Many readers always feel that understanding a variety of hardware is a more difficult thing, in fact, as long as you understand some of the basic knowledge of the type of hardware and parameters, you can have a more rational understanding of computer hardware.

One, look at the parameters of the CPU

CPU is CentralProcessingUnit (Central Processing Unit) of the acronym, the CPU is generally composed of logical computing units, control units and storage units. In the logic operation and control unit includes some registers, these registers are used for the CPU in the process of data processing data is temporarily saved. We need to focus on understanding the main indicators/parameters of the CPU are:

1. main frequency

Main frequency, that is, the clock frequency of the CPU, simply put is the operating frequency of the CPU, for example, we often say that the P4 (Pentium IV) 1.8GHz, this 1.8GHz (1800MHz) is the main frequency of the CPU. Generally speaking, the number of instructions completed in a clock cycle is fixed, so the higher the main frequency, the faster the CPU speed. Main frequency = external frequency X multiplier frequency.

Additionally, it should be noted that AMD's AthlonXP series processors have mainframe frequencies that are nominal PR (PerformanceRating) values, such as Athlon

XP1700+ and 1800+. For example, an Athlon

XP that actually runs at 1.53GHz is labeled as 1800+, and is also shown as such in the system boot self-test screen, Windows system properties, and detection software such as WCPUID.

2. External Frequency

The external frequency is the external clock frequency of the CPU, and the standard external frequency of the motherboard and CPU is mainly 66MHz, 100MHz and 133MHz. In addition, the more adjustable and higher the external frequency of the motherboard, the better, especially for overclockers more useful.

3. Multiplier

The multiplier is the number of times the difference between the CPU's external frequency and its main frequency. For example, the AthlonXP2000+ CPU has an external frequency of 133MHz, so its multiplier is 12.5x.

4. Interface

Interface refers to the interface that connects the CPU to the motherboard. There are two main types, one is the card interface, known as SLOT, card interface CPU like we often use a variety of expansion cards, such as graphics cards, sound cards, etc. is vertically inserted into the motherboard, of course, the motherboard must have a corresponding SLOT slot, the interface of the CPU has been eliminated. The other type is the mainstream pin interface, called Socket, Socket interface CPU has hundreds of pins, because the number of pins is different and called Socket370, Socket478, Socket462, Socket423 and so on.

5. Cache

Cache is the memory that allows high-speed data exchange, which exchanges data with the CPU before the memory, so it is extremely fast, so it is also known as cache. There are two general types of caches associated with processors - L1 caches, also known as internal caches, and L2 caches, also known as external caches. For example, the Pentium4 "Willamette" core product uses a 423-pin architecture with a 400MHz front-side bus, a 256KB full-speed L2 cache, an 8KB first-level tracking cache, and the SSE2 instruction set.

@1 Internal Cache (L1Cache)

This is what we often refer to as a Level 1 cache. The built-in cache inside the CPU can improve the CPU's operating efficiency, the built-in L1 cache capacity and structure of the CPU performance has a greater impact, the larger the L1 cache, the CPU works with the slower access speed of the L2 cache and memory exchange data between the fewer the number of times, relative to the computer's computing speed can be increased. However, the cache memory are composed of static RAM, the structure is more complex, in the case of the CPU core area can not be too large, the capacity of the L1 cache can not be made too large, L1 cache capacity unit is generally KB.

@2 External Cache (L2Cache)

CPU external cache, the cost of external cache expensive, so the Pentium4 Willamette core. Pentium4 Willamette core for the external cache 256K, but the same core Celeron 4 generation only 128K.

6. Multimedia instruction set

In order to improve the computer in the multimedia, 3D graphics applications, a number of processor instruction sets came into being, the most famous three are Intel's MMX, SSE/SSE2 and AMD's 3D graphics. The most famous three are Intel's MMX, SSE/SSE2 and AMD's 3DNOW! Theoretically, these instructions provide a comprehensive enhancement to popular multimedia applications such as image processing, floating point computing, 3D computing, video processing, audio processing, and more.

7. Manufacturing Process

Early processors were manufactured using a 0.5-micron process. As CPU frequencies increased, the original process was no longer able to meet the requirements of the product, which led to the emergence of the 0.35-micron as well as the 0.25-micron process. The finer the production process means that the more electronic components integrated into the unit volume, and now, the processor products manufactured using 0.18 micron and 0.13 micron is the mainstream of the market, for example, the Northwood core P4 using the 0.13 micron production process. And in 2003, Intel and AMD's CPUs will have a 0.09-millimeter manufacturing process.

8. Voltage (Vcore)

The operating voltage of a CPU refers to the voltage required for normal operation of the CPU, and is related to the manufacturing process and the number of integrated transistors. The lower the normal operating voltage, the lower the power consumption and the lower the heat generation, and the direction of CPU development is also to ensure that the performance of the basis, and constantly reduce the voltage required for normal operation. For example, the old core Athlon

XP's operating voltage is 1.75v, while the new core AthlonXP's voltage is 1.65v.

9. Packaging

The so-called CPU packaging is the last process in the CPU production process, packaging is the use of a specific material will be the CPU chip or CPU module cured in which to prevent damage to the protection measures, generally must be in the package to prevent damage to the CPU chip or module. The CPU package depends on the CPU installation form and device integration design, from a broad classification point of view, usually using the Socket socket for installation of the CPU using the PGA (grid array) way of packaging, while using the Slotx slot installation of the CPU are all used in the form of SEC (Single Edge Connector Box) packaging. The PLGA (Plate-Layer-Grid-Array) package is also available. Nowadays, there are also PLGA (PlasticLandGridArray), OLGA (OrganicLandGridArray) and other packaging technologies. Due to the increasingly fierce competition in the market, the current direction of development of CPU packaging technology to save costs.

10. Integer Unit and Floating Point Unit

ALU - Arithmetic Logic Unit, this is what we call "integer" unit. Mathematical operations such as addition, subtraction, multiplication and division and logical operations such as "OR, AND, ASL, ROL" instructions are executed in the ALU. In most software programs, these operations make up the majority of the program code.

And the floating-point unit FPU (FloatingPointUnit) is mainly responsible for floating-point operations and high-precision integer operations. Some FPUs also feature vector operations, while others have specialized vector processing units.

The integer processing capability is the most important manifestation of the CPU's computing speed, but the floating-point computing capability is related to the CPU's multimedia, 3D graphics processing is an important indicator, so for the modern CPU for the floating-point unit computing ability of the strength of the CPU's performance can be better shown.

Two, look at the parameters of the motherboard

The motherboard is the total platform of all computer accessories, so you buy or use the motherboard first of all to understand how the core functions of your motherboard, what type of CPU it can support, memory, graphics cards, how many PCI devices can support, and so on.

1. board

The circuit board to do motherboards in the computer to use, but also need to be made into a different board type, the following we will give you a brief introduction to the common motherboard board type. AT board type is one of the most basic type of board, which is characterized by the structure of a simple, inexpensive, and its standard size of 33.2cmX30.48cm, the AT motherboards need to be with the AT chassis power supplies and other matching

Baby

AT is an improved version of the AT architecture motherboard, which has a more reasonable layout and can support AT/ATX power supplies, but has fallen out of favor due to the popularity of the ATX architecture.

While the ATX board type is like a large horizontal AT board, so that it is easy to ATX chassis fans for CPU cooling, and many of the board's external ports are integrated into the motherboard, not like the AT board many COM ports, print ports have to rely on the cable to output. There is also a Micro

ATX small form factor, which supports up to four expansion slots, reducing size, power consumption and cost.

The NLX board, which is favored by brand-name manufacturers, is shaped like a motherboard with a graphics card inserted, and consists of two parts: one part is a baseboard with logic control chips and basic input and output ports, and the other part is an add-on board with slots for AGP, PCI, and ISA that is inserted into special ports on the baseboard like a graphics card, which allows for more space and easy disassembly and installation. convenient.

2. Core

The motherboard chipset is the core of a computer's motherboard, and it represents the main technical characteristics of the motherboard. With the adoption of different motherboard chipsets, various computer motherboards support different functions accordingly. For example, a motherboard using Intel's i845D motherboard chipset, i845D motherboard chipset and its predecessor i845 compared to its main change is that it provides support for mainstream DDR memory. Its main features are described on its motherboard manual "The i845D chipset consists of the I845D chip and the ICH2 chip, which supports Socket 478 socket Pentium4 processors, supports 400MHz

FSB (Front Side Bus), supports AGP4X, integrates AC97 sound, and supports ATA100 hard disk drive transfer specifications."

3. Socket Types

The CPU socket is where the processor is installed on the motherboard. The main mainstream CPU sockets are Socket370, Socket478, Socket423 and SocketA. Socket370 supports PIII and new Celeron, CYRIXIII and other processors; Socket423 is used for early Pentium4 processors, while Socket478 is used for current mainstream Pentium4 processors. Socket423 is used for early Pentium4 processors, while Socket478 is used for the current mainstream Pentium4 processors. Socket

A (Socket462) supports AMD's Viperon and Velociraptor processors. The other CPU socket types are Socket7, which supports Pentium/Pentium MMX and K6/K6-2 processors; SLOT1, which supports PII or PIII; and SLOTA, which is used by AMD

ATHLON.

4. Supported Memory Types

Nowadays, we mainly use two kinds of memory: 168 lines of SDRAM and 184 lines of DDRSDRAM memory; SDRAM memory, 168 lines, 64-bit bandwidth, 3.3v operating voltage, which supports different specifications such as PC66/100/133/150, etc.; and the main feature of DDR memory is that it can use clock pulses to generate the memory. feature is that it can use the rising and falling edges of the clock pulse to transfer data, so the speed of DRAM can be increased exponentially without increasing the operating frequency.

Nowadays, DDR memory is mainly available in PC1600/PC2100/PC2700/PC3200 specifications. For example, one motherboard specification states that it "supports two 184-pin DDR memory slots, which can support 2GB of memory capacity." This statement indicates that it does not support 168 lines of SDRAM, and that it has two DDR memory slots that can be used to plug in two pieces of DDR memory. In addition, you can see from the other text about DDR that this motherboard can only support PC1600/PC2100 specification DDR memory.

5. Supported AGP Slot Types

The AGP1X (266Mbps), AGP2X (533Mbps), AGP4X (1066Mbps), AGPPro and AGP Universal Slots (1066Mbps), AGP8X (2133Mbps), and several other graphics card slots are different. The graphics card specification slots in the back of the line are generally compatible with the graphics card specification slots in the front of the line, for example, an AGP4X specification graphics card slot can be used with an AGP2X graphics card, while an AGP4X graphics card can not be used properly in an AGP2X graphics card slot (note: there is also an AGP2X/4X universal slot).

So, the type of graphics card your motherboard supports is key to making the right choice for your graphics card. For example, if a motherboard has an AGP4X slot, you can buy an AGP1X/2X/4X graphics card to work properly on it.

Three, look at the parameters of the hard disk

As we all know, the hard disk on the market is mainly divided into two categories: IDE and SCSI. SCSI hard disk has the characteristics of fast speed, large capacity, stable use, is the front-runner of the hard disk technology, but its price is too expensive, and it is mainly used in the more professional occasions.

While the IDE hard disk, although said in the technical standard still with SCSI hard disk has some gap, but undoubtedly the gap has become smaller and smaller, today's IDE hard disk also has a fast speed, large capacity, and its price is cheap, has become the first choice for home occasions.

The IDE hard disk according to the size of its internal platter diameter, can be divided into 5.25, 3.5, 2.5 and 1.8-inch hard disk, etc. 2.3 and 1.8-inch platter diameter size of the hard disk is mainly used for laptop computers and other equipment; 5.25 and 3.5 platter diameter hard disk is mainly used in desktop computers, desktop computers are most commonly used is the size of the 3.5-inch platter diameter of the hard disk.

1. Capacity of the hard disk

We will first ask when we buy a hard disk, this hard disk is how big ah? Answer: 40GB, 80GB, is the capacity of the hard disk. It generally refers to the capacity of the hard disk after formatting. The larger the capacity of the hard disk, the better.

Secondly, when choosing the capacity, you can also prioritize the products with large single-disk capacity. The larger the capacity, the more advanced the technology and the easier it is to control costs. For example, a 40GB hard drive with a 10GB capacity would require 4 platters and 8 heads, while a 20GB capacity would require 2 platters and 4 heads, and a 40GB capacity would require 1 platter and 2 heads, which would save you a lot of money and improve the stability of the hard drive.

2. The speed of the hard disk

This is also a matter of concern. It refers to the speed of rotation of the spindle inside the hard disk. IDE hard disk on the market today is mainly divided into 5400RPM (rpm), 7200RPM (rpm) two kinds of speed. In the case of capacity price are similar, you can prefer the fast speed of 7200 RPM hard disk products.

3. Hard disk transfer rate

The hard disk transfer rate is also one of the important parameters of the hard disk. It mainly refers to the transfer rate of the hard disk's external and internal data, which are measured in Mb/s (megabits per second) or MB/s (1MB=8Mb). Hard disk external transfer rate (burstdatatransferrate) that is, the hard disk burst data transfer rate, which generally refers to the rate of the hard disk's data interface. Now the ATA/66/100/133 interface hard drive transfer rate can be up to 66-133MB/S.

And the hard drive's internaldatatransferrate refers to the maximum data transfer rate between the magnetic head and the hard drive's cache, and in this regard, the maximum internaldatatransferrate of the mainstream hard drives on the market is generally up to

4. Hard drive cache

The size of a hard drive's cache is also one of the hard drive's key indicators. The cache of a hard disk is the high-speed memory inside the hard disk. Today's hard drives use a type of cache that is mostly SDRAM, but there are exceptions such as EDODRAM. The larger the capacity of the cache, the better, it is directly related to the read speed of the hard disk, today's hard disk cache capacity is mostly 2M, and to the 8M of the larger capacity over. However, there are also a few products with only 512K cache, which you need to pay attention to.

5. Hard disk head

The type of magnetic head used on the hard disk, mainly MR and GMR two kinds of head, GMR giant magnetoresistive magnetic head has begun to replace the MR head to become the mainstream of the hard disk head.

MR magneto-resistive heads, the use of write and read heads separate head structure, it is through the change in resistance to sense the signal amplitude, quite sensitive to changes in the signal, so that the accuracy of its read data is also correspondingly improved, and because of the amplitude of the signal it reads has nothing to do with the width of the magnetic track, and therefore, the magnetic track can be made very narrow, which improves the density of the platters, which makes the capacity of the hard disk This allows the capacity of the hard disk to be very large.

Compared to MR heads, GMR heads use materials with a better magnetoresistive effect and a multilayer thin-film structure, which is more sensitive than MR heads, thus allowing for higher storage densities. Today's MR heads can achieve disk storage densities of 3Gbit-5Gbit/in2 (gigabits per square inch), while GMR heads can achieve 10Gbit-40Gbit/in2 or more.

6. Hard disk seek time

The seek time of the hard disk is also one of the important parameters to understand the hard disk. It mainly refers to the averageageseektime, singletrackseek, maxfullseek, and average wait time. They are all measured in ms (milliseconds).

The average seek time of a hard drive is the time it takes for the hard drive's magnetic head to move to the track where the data is located, and the smaller the value, the better; most IDE hard drives today have an average seek time of less than 9 ms. The average seek time for IDE hard drives today is 9ms or less. The inter-channel seek time of a hard drive is the time it takes for the heads to move from one channel to another, and this time is also as short as possible.

The maximum seek time of a hard disk refers to all the time it takes for the disk's magnetic head to move from the beginning until it finally finds the data block it needs, and its value is also the smaller the better, and most of the mainstream IDE hard disks on the market have a maximum seek time of 20ms or less. As for the average waiting time of the hard disk, it refers to the time when the magnetic head moves to the track where the data is located, and then waits for the desired data block to continue to rotate under the head, and its value is also the smaller the better.

Four, look at the parameters to recognize the monitor

The importance of the monitor is self-evident, we should be from what aspects to understand it?

1. CRT display

Visual area

Visual area refers to the maximum range of your monitor can display graphics, we usually say 15 inches / 17 inches actually refers to the size of the tube, and the actual visual area is far from this size. 14-inch monitors tend to be only 12 inches in the visual range, 15-inch monitors. Visual range in 13.8 inches or so, 17-inch monitor visual area is mostly in 16 inches or so. When buying a monitor, it makes sense to pick one with a larger viewing area to give you a wider field of vision.

Dot Pitch/Bar Pitch

Dot Pitch is one of the most important technical parameters of the CRT, which is measured in mm (millimeters), and it refers to the straight-line distance between the two closest fluorescent dots of the same color of the CRT. The smaller the better, the smaller the dot pitch, the clearer the display graphics, the current display usually uses 0.28 dot pitch. In addition, there is a concept of horizontal dot pitch, 0.28 dot pitch of the tube its horizontal dot pitch of 0.24.

The tube has a shade (ShadowMask) and shade grid (ApertureGrilleMask) two types. The grating distance is the distance between the parallel gratings of a ShadowMask tube. The advantages and disadvantages of the shade and grille type tubes, the advantages of using the grille type tube is that its grating distance after a long period of time will not be deformed, even if the use of many years there will be no degradation of picture quality; on the other hand, because of the grille type can be through more light, so that you can achieve higher brightness and contrast, so that the image color is more vivid, realistic and natural.

Resolution

Resolution defines the resolution of a monitor's picture, which can be achieved as long as the monitor's bandwidth is greater than the acceptable bandwidth at a given resolution. It is usually expressed as a product, which indicates the number of pixels in the horizontal direction (horizontal resolution) and the number of pixels in the vertical direction (vertical resolution), e.g. 800X600dpi, 1024X768dpi, etc.

The resolution of the monitor is affected by the size of the monitor, the pixel pitch of the picture tube, circuit characteristics, etc. It is worth mentioning that the resolution of a monitor can be achieved at a refresh frequency of more than 75Hz is its real resolution. And now some manufacturers advertise the maximum resolution is often in the refresh frequency is very low under the conditions of the maximum resolution can be achieved, generally unable to provide more than 75Hz stable image, not very meaningful.

Refresh rate

Refresh rate is the speed at which the monitor screen is refreshed, which is measured in Hz (hertz). The lower the refresh rate, the more flickering and jittering of the image, the faster the eye fatigue, in general, if you can achieve a refresh rate of 80Hz or more can basically eliminate the image flicker and jitter feeling.

Horizontal refresh rate, also known as line frequency (Horizontaiscanningfrequency), it is the number of times the display scans the horizontal line in 1 second, its unit is kHz. vertical refresh rate, also known as field frequency (Verticalscanningfrequency), the unit is Hz, which is determined by the horizontal refresh rate and screen resolution, vertical refresh rate and screen resolution. It is determined by the horizontal refresh rate and the screen resolution. Verticalscanningfrequency indicates how many times the screen image is redrawn per second, which means the number of times the screen is refreshed per second.

Video Bandwidth

Bandwidth is the range of frequencies that can be processed by a particular electronic device, and it determines the range of information that can be processed by a monitor. The video bandwidth (BandWidth) is the total number of pixels scanned by the electron gun per second, which is measured in megahertz (MHz), and theoretically the video bandwidth is the product of the horizontal resolution, vertical resolution, and vertical refresh rate. The wider the bandwidth, the higher the frequency that can be processed, and the better the image quality. Professional monitors and ordinary monitors the difference between their video bandwidth is huge, the higher the bandwidth, the higher the price of the monitor, high-end monitors whose bandwidth can reach more than 200MHz, but the daily home monitor can have about 100MHz bandwidth to meet our needs.

2. LCD liquid crystal display

To understand the LCD monitor should mainly start from the following points:

Brightness/contrast

LCD brightness in square candles (cd/m2) or nits (lumens) for the unit, LCD monitors due to the number of backlight than the laptop monitor to be more, so the brightness LCD monitors look significantly brighter than laptop ones. Their brightness generally ranges from 150nits to 500nits. Higher brightness values certainly indicate higher product performance.

But one thing to note is that some of the low-grade LCD monitors on the market have more serious uneven brightness phenomenon, the brightness of its center and the bezel part of the area of the brightness difference is relatively large. So we should be more important in the purchase of LCD monitor brightness uniformity, that is, the product's display effect whether the screen center or the four sides of the requirements of uniform brightness, the four sides of the phenomenon of no obvious darkness, which we need to focus on the purchase of LCD monitors.

The contrast ratio is a direct reflection of the LCD monitor can reflect the rich color gradient parameters, the higher the contrast ratio, the better the restoration of the picture hierarchy, even when watching a very bright photo, the dark parts of the details can be clearly reflected, the current market of LCD monitors contrast ratio is generally in the 150:1 to 350:1 between the high-end LCD monitors are also higher. In the case of similar prices, you should first consider choosing a product with a higher contrast ratio.

Viewing Angle

Since LCD uses light transmission to visualize, there is the problem of viewing angle, so the ordinary LCD has a disadvantage that the viewing angle is small. In an LCD, both direct and oblique light penetrate the pixels in the same display area, so viewing the screen from an angle greater than the viewing angle will reveal phenomena such as ghosting and discoloration of the image. Therefore, the viewing angle refers to the maximum angle at which the image of the LCD screen can be clearly seen, and the larger the viewing angle, the better.

Usually, the LCD viewing angle is symmetrical left and right, but up and down is not necessarily. Currently on the market 15-inch LCD monitor horizontal viewing angle is generally 120 degrees or more, while the vertical viewing angle is much smaller than the horizontal viewing angle, the prevailing level is up and down asymmetry **** 95 degrees or more.

Response time

Signal response time is the time it takes for a pixel to go from bright to dark and then from dark to bright. Response time reflects the speed at which each pixel of an LCD monitor responds to an input signal, and the smaller the value, the better. In the past, the response time of most LCD monitors ranged from 20 to 100 ms, but newer models nowadays are able to achieve a response time of less than 20 ms. The smaller the response time, the less the motion picture will make the user feel like a shadow.

The simple way to judge is to move the mouse quickly, in general, low-grade LCD monitors, the cursor in the rapid movement, the process will disappear until the mouse is positioned, no longer moving after a short period of time, will reappear; and in the general speed of the action, the movement of the process will be clear to see the mouse moving traces. These for you to play action or 3D games or watch VCD when the impact is great, slow signal response of the LCD monitor will appear very obvious image trailing, "ghosting" and other phenomena, seriously affecting the display effect. In addition to the indicators given in the product manual or leaflet, the actual test is the most important when you buy.

Size

The size of the monitor is the length of the diagonal of the picture tube, the unit is inches (1 inch = 2.539 cm), while the size of the LCD and CRT monitors are different, the size of its size is generally the true display size, the main size of the LCD monitors on the market at present 13.3, 14, 15, 17, 18 inches, etc., the price of the LCD monitor mainly Determined by the size of the LCD screen.

Resolution

LCD and CRT monitors are different, it has a fixed resolution, only in the specified use of the resolution of its picture quality is the best, in other resolutions can be expanded or compressed, the picture will be displayed.

In the display of less than the optimal resolution of the screen, LCD using two ways to display, one is the center of the display, for example, in the display of 800 * 600 sub resolution, the monitor is only in the middle of the 800 * 600 pixels to display the screen, the surrounding is shaded, this way due to the resolution of the signal is a one-to-one correspondence, so the picture is clear, the only regret is that the picture is too small.

Another way is to display the image in the middle of the screen.

The other is to expand the way, is the 800 * 600 of the screen by calculating the way to expand the resolution of 1024 * 768 to display, due to this way to deal with the signal and the pixel is not a one-to-one correspondence, although the picture is large, but also caused the image of the distortion phenomenon, clarity and accuracy will be affected. Currently on the market 14-inch / 15-inch LCD monitors are the best resolution of 1024 * 768, 17 inches of the best resolution is 1280 * 1024.

Five, look at the parameters of the memory

With memory chips, coupled with a less complex process of manufacturing, many of the strength of the manufacturers can produce finished products to the memory, in addition to the other, you can also use the memory to buy or use the memory, but also to make sure that you are not using the memory. In addition to this, there are a number of other things you should know about memory, whether you're shopping for it or using it.

1. Operating frequency

The operating frequency of the memory is the standard specification of the memory. For example, the standard memory frequency of PC100 is 100MHz, and the frequency of PC133 is 133MHz. DDR memory is developed on the basis of SDRAM memory, and since it is based on the double transmission of data on the basis of the same frequency of SDRAM, its bandwidth is more than double the same frequency of SDRAM, for example, the DDR266 memory runs at 133MHz when its actual operating frequency is 266MHz. The actual operating frequency is 266MHz, and the bandwidth is 2.1GB/S.

If you want to buy a DDR333 memory, but the merchant took a DDR266 memory to you, the more simple and feasible way to identify is that you can understand from the DDR memory access time, for example, -7 and -7.5 nanoseconds of the general DDR266 memory, -6 nanoseconds of the general For example, -7 and -7.5 nanoseconds is usually DDR266 memory, -6 nanoseconds is usually DDR333 memory, -5 nanoseconds is usually DDR400 memory.

The successor to DDR, DDRII, is even more advanced than DDR in that it quadruples the data transfer rate of DDR, making it twice as fast as DDR! If it also runs at 133MHz external frequency, its operating frequency is 532MHz/S, and its bandwidth is up to 4.2GB/S.

2. CAS value

You know, memory has a CAS (ColumnAddress

Strobe, column address selective pulse) latency, the memory stores the information on the Like a large table, the rows (Column) and columns (Row) are used to locate all the information stored in memory, and CL means how many clock cycles it takes to find the corresponding location.

For SDRAM, there are generally two values to choose from: 2 and 3, while DDR memory can be divided into two types: 2 and 2.5. The smaller the CAS value, the better, that is to say, the performance of DDR memory products with a value of 2 is better than that of the products with a value of 2.5, and if you need to CAS value of 2, then you have to pay attention to the selection of the JS with a value of 2.5 to make the product of 2 products to be sold to you (can be actually use or test with memory testing software).

3. Memory labeling

Additionally, knowing the numbering of some DDR memory chips can also give you a deeper understanding of DDR memory. Here we take the most common HY's DDR memory as an example:

HYXXXXXXXXXXXXXXXXXX-XX

1234567891011

1: represents HY's factory label

2: for the memory chip type-5D: DDRSDRAMS

3: Process and operating voltage-V: CMOS, 3.3V; U:CMOS, 2.5V

4: Chip capacity and refresh rate-64:64MB, 4kref; 66:64MB, 2kref; 28:128MB. 4kref; 56:256MB, 8kref; 12

:512MB, 8kref

5: Chip structure (data width) -4:X4 (data width 4bit); 8:x8; 16:x16; 32:x32

6: Number of BANKs -1:2BANKs; 2:4BANKs

7: I/O interface-1:SSTL_3; 2:SSTL_2

8: Chip kernel version-Blank:1st generation; A:2nd generation; B:3rd generation; C:4th generation

9: Energy Level-Blank:Normal; L:Low Energy

10: Package Format-T:TSOP; Q:TQFP; L:CSP(LF-CSP); F:FBGA

11: Operating Speed-33:300MHz

6. Look at the parameters of the graphics card

1. Core Frequency

The core frequency of the graphics card is the default operating frequency of the graphics card, and the value is usually The higher the value, the better. For example, ATI's RV250 (Radeon9000/9000Pro), which use a 0.18-micron manufacturing process, can handle up to four parallel rendering pipelines of up to 1 billion pixels/s. The Radeon

9000 and 9000Pro have similar features except for a different core frequency. The Radeon 9000 comes with a 250MHz

GPU and 400MHz DDR memory (200MHz*2), while the 9000Pro has 275MHz/550MHz

DDR (275MHz*2), so the latter has more performance.

2. About Graphics Memory

Graphics memory is one of the most important factors affecting the performance of a graphics card.

Capacity of graphics memory

When it comes to graphics memory, we can definitely say that this graphics card is 16M, that one is 32M, and so on, and all these refer to the capacity of the graphics memory. The graphics memory is like a big warehouse that holds data and information, including frame buffers, Z-buffers, and texture buffers, all of which take up the capacity of the graphics memory and increase with screen resolution and color depth, so the size of the memory capacity affects the performance of the graphics card.

Graphics memory speed

Graphics memory speed is the operating frequency of the memory, expressed in nanoseconds on the memory particles, generally 6ns, 5ns, 4ns, 3.5ns, 3ns, and so on, the operating frequency of the memory = 1 / the speed of the memory, for example, 5ns operating frequency of the memory = 1/5ns = 200MHz.

Graphics memory bit-width and bandwidth

As you know, the information in the graphics memory is not static, it needs to be constantly exchanged with the core of the graphics card (GPU or VPU), which involves the concept of graphics memory bit-width. Bit-width refers to the bit-width of the interface between the graphics particle and the external data exchange, usually 8bit, 16bit, 32bit, etc. The bit-width of the graphics chip is the bit-width of the interface between the graphics particle and the external data exchange.

The memory bandwidth is the maximum amount of data that can be exchanged per second. As we know, the GPU of a graphics card calculates the data to be exchanged between the graphics card and the memory, so if the memory bandwidth is not high enough, it will seriously affect the performance of the graphics card. The memory bandwidth is determined by the memory bit-width and memory frequency, as well as the number of memory particles***, i.e., memory bandwidth = memory bit-width X memory frequency X number of memory particles/8.

For example, a GeForceMX440SE graphics card adopts the HYNIX4ns DDRSDRAM memory, numbered HY5DV "64" "16" 22AT, which is 64 megabytes of memory particles, and is used in a variety of applications including video games, music and movies.

3. Pixel fill factor

Pixel fill factor

The Pixel Fill Rate

3.

Pixel fill factor is a term we hear a lot when shopping for graphics cards. What is pixel fill rate? Pixel fill rate is the number of dots that the graphics chip/card can draw on the monitor per second.

For example, if you have a screen resolution of 800x600, it takes 800x600=480,000 pixels to form each image on the screen. Then take