Computer parameters and terminology
I. CPU products
CPU is the heart of the computer, and the CPU used by the computer basically determines the performance and grade of this computer. With the development of CPU, the frequency has reached 2GHZ. When we decide which CPU to buy or read articles about CPU, we often see parameters and terms such as external frequency, frequency doubling and cache. Let me give you a brief introduction to these commonly used CPU-related terms.
cpu
The central processing unit (CPU) is the brain of the computer, and more than 90% of the data information is completed by it. Its working speed directly affects the running speed of the whole computer. CPU integrates tens of thousands of transistors and can be divided into control unit (control unit; CU), logic unit (arithmetic logic unit; ; ALU), memory unit (memory unit; MU) three parts. According to the internal structure, it can be divided into integer operation unit, floating-point operation unit, MMX unit, L 1 buffer unit and register.
basic frequency
The clock frequency inside the CPU is the working frequency when the CPU performs operations. Generally speaking, the higher the main frequency, the more instructions completed in a clock cycle, and the faster the CPU runs. However, due to different internal structures, not all CPUs with the same clock frequency have the same performance.
External frequency
That is, the system bus, the frequency of data transmission between CPU and peripheral devices, specifically the bus speed between CPU and chipset.
frequency doubling
There is no concept of frequency doubling. The main frequency of CPU is the same as the speed of system bus, but the speed of CPU is getting faster and faster, and the frequency doubling technology was born. The system bus can work at a relatively low frequency, and the CPU speed can be infinitely improved by frequency doubling. Then the calculation method of CPU main frequency becomes: main frequency = external frequency x frequency doubling. In other words, frequency doubling refers to the multiple of the difference between CPU and system bus. When the external frequency is constant, the higher the frequency multiplication, the higher the CPU frequency.
Cache (cache)
Most data information processed by CPU is retrieved from memory, but the operation speed of CPU is much faster than that of memory. So in this transmission process, a memory is placed to store data and instructions frequently used by CPU. This can improve the data transmission speed. It can be divided into first-level cache and second-level cache.
Level 1 cache
That is, L 1 cache. It is integrated in the CPU and used to temporarily store data while the CPU is processing data. Because the working frequency of cache instructions and data is the same as that of CPU, the larger the cache capacity of L 1 level, the more information is stored, which can reduce the number of data exchanges between CPU and memory and improve the running efficiency of CPU. However, cache memories are all composed of static RAM, and their structures are complex. In the limited CPU chip area, the capacity of L 1 level cache cannot be made too large.
L2 cache
That's the L2 cache. Due to the limitation of L 1 level cache capacity, in order to improve the operation speed of CPU again, a high-speed memory, namely the secondary cache, is placed outside the CPU. The main working frequency is flexible, which can be the same as or different from the CPU. When the CPU reads data, it first looks in L 1, then in L2, then in internal memory, and then in external memory. Therefore, the influence of L2 on the system can not be ignored.
Memory bus speed: (memory bus speed)
Refers to the data exchange speed between CPU and L2 cache and memory.
Expansion bus speed: (expansion bus speed)
Refers to the data transmission speed between CPU and expansion device. The expansion bus is a bridge between CPU and external devices.
Address bus width
Simply put, it is how much memory the CPU can use to read the physical address space of data.
Data bus width
The data bus is responsible for the data flow of the whole system, and the width of the data bus determines the amount of information transmitted between CPU and secondary cache, memory and input/output devices.
manufacturing technique
In the process of producing CPU, it is necessary to process various circuits and electronic components and make wires connecting various components. The manufacturing accuracy is expressed in microns (um), and the higher the accuracy, the more advanced the manufacturing process. The same material can make more electronic components. The thinner the connecting wire, the higher the integration of CPU and the smaller the power consumption of CPU. In this way, the main frequency of CPU can also be improved, and the highest frequency can reach 600MHz in the production process of 0.25 micron. The CPU of 0. 18 micron production process can reach the level of G Hz. 0. 13 micron CPU will be on the market soon.
operating voltage
Refers to the voltage required for the CPU to work normally. Increasing the working voltage can enhance the internal signal of CPU and increase the stable performance of CPU. But it will lead to the problem of CPU heating, change the chemical medium of CPU and reduce the life of CPU. In the early days, the working voltage of CPU was 5V. With the improvement of manufacturing technology and main frequency, the working voltage of CPU has changed greatly. The voltage of PIIICPU is 1.7V, which solves the problem of excessive CPU heating.
MMX (Multimedia Extension).
The earliest SIMD instruction set developed by Intel can improve the speed of floating-point and multimedia operations.
SIMD stream extension.
The second generation SIMD instruction set developed by Intel has 70 instructions, which can improve the speed of floating-point and multimedia operations.
3DNow！ (3D without waiting)
The SIMD instruction set developed by AMD can enhance the speed of floating-point and multimedia operations, and its instruction number is 2 1.
Second, the motherboard
Everyone likes to compare CPU to the brain or heart of a computer, so the computer motherboard can be called the nervous system of a computer. Motherboard is a high-tech, high-tech integrated product, and it is inevitable that everyone will be confused when they are busy. Therefore, it is of great benefit to know some basic knowledge of motherboard first. Below, I will briefly explain some common terms of the motherboard to you.
Motherboard:
The English "motherboard" is the largest circuit board in a computer and the core component of a computer system. It is covered with various slots (sound card/graphics card/modem/etc.). ), interface (mouse/keyboard, etc. ) and electronic components, perform their respective duties, and closely connect various peripheral devices. Its performance will have a decisive impact on the overall index of the computer.
Central processing unit:
Also known as the microprocessor. It is called the heart of the computer. It is actually an electronic component, which consists of millions of transistors and is divided into three parts: control unit, logic unit and storage unit. Its working principle is that the control unit transmits and distributes the input instructions, then sends them to the logic unit for processing to form data, then stores them in the memory, and finally waits for them to be handed over to the application program.
BIOS (basic input-&; -output-system basic input/output system):
After literal translation, the Chinese name is "basic input and output system", and its full name should be ROM-BIOS, which means read-only memory basic input and output system. In fact, it is a set of programs solidified on a ROM chip on the computer motherboard, which stores the most important basic input and output programs of the computer, system setting information, self-check program and boot program when the system starts.
CMOS:
CMOS is a readable RAM chip on the computer motherboard, which is used to protect the hardware configuration of the current system and the user's setting of some parameters. Now the manufacturer has put the CMOS program into the BIOS chip, and after booting, press a specific key to enter the CMOS setup program to set up the system. So it's also called BIOS setup.
Chipset (chipset):
It is the core of the motherboard circuit. In a sense, it determines the level and grade of the motherboard. It is the collective name of "South Bridge" and "North Bridge", that is, a chipset that integrates complex circuits and components into several chips to the greatest extent.
Northbridge: the chip closest to the CPU on the motherboard, which is responsible for contacting the CPU and controlling the transmission of Northbridge memory, AGP and PCI data.
South bridge: a chip on the motherboard, which is mainly responsible for I/O interface and control of IDE devices.
MCH (memory controller hub):
Memory controller center, responsible for connecting CPU, AGP bus and memory.
ICH (input/output controller hub):
I/O controller center, responsible for connecting PCI bus, IDE devices, I/O devices, etc.
FWH (firmware controller):
Firmware controller, whose main function is to store BIOS.
Input/output chip:
The I/O control circuit is provided on the motherboard of grade 486 or above. It is responsible for providing serial and parallel interfaces and floppy disk drive control interfaces.
PCB:
That is, several layers of resin materials are bonded to the motherboard circuit board, and copper foil wiring is used inside. The general PCB circuit board is divided into four layers, the upper and lower layers are signal layers, and the middle two layers are grounding layer and power layer. Put the ground plane and the power plane in the middle, so that the signal line can be easily corrected. The circuit board of a good motherboard can reach six layers, because the signal lines must be far enough apart to prevent electromagnetic interference. A six-layer board can have three or four signal layers, one ground layer and one or two power layers to provide sufficient power.
AT board type:
That is, the "vertical" board design, that is, the short side is located at the back panel of the chassis. It was originally applied to IBM PC/AT. AT motherboard size is13x12 inch.
Baby-AT board type:
With the substantial improvement of the integration of electronic components and control chipsets, a relatively small-sized Baby AT main board structure has been introduced. The size of baby AT is 13.5×8.5 inches.
ATX (external) board type:
It is a new type of main board structure proposed by Intel Corporation. Its layout is a "horizontal" board design, just like turning the Baby-AT board upside down, which increases the space of the motherboard outlet and enables the motherboard to integrate more expansion functions.
Micro ATX board type:
Main board structure was put forward by Intel Company in 1997, mainly to reduce the motherboard size by reducing the number of PCI and ISA slots.
At the power supply:
It consists of two groups of interfaces, P8 and P9. Each interface has six pins and supports voltages of +5.0V,+12V, -5V and-12V, but does not support voltages of+3.3v. ..
ATX power supply:
ATX power supply is the power supply of ATX motherboard, which adds some new functions. First, it can provide a set of micro-current (5V/ 100MA) power supply when it is turned off. The second is to increase the 3.3V low-voltage output.
Slot 1:
A CPU socket specially designed by Intel for Pentium II is a 242-pin slot, which provides greater internal transmission bandwidth and CPU performance.
Socker 370:
INETL CPU slot designed for Celeron series reduces the cost. Support VRM8. 1 specification, and the core voltage is about 2.0V.
Socker 370 II:
INETL is designed for Pentium III Coppermine and Celeron II, supports VRM8.4 specification, and its core voltage is about1.6V..
Slot a:
AMD made it for K7 series CPU, which looks like slot 1.
Socket a:
AMD dedicated CPU socket, 462 pins.
Socker 423:
Intel is committed to the socket of the first generation Pentium IV processor.
Socket 478:
Special CPU socket for Pentium IV of Willamette kernel.
SIMM (Single Column Memory Module):
72-wire memory slot.
DIMM (Dual In-line Memory Module):
A memory slot. 168 line structure.
SDRAM (synchronous burst RAM):
Synchronous burst memory. It is a 168 line with a voltage of 3.3V, a bandwidth of 64bit and a speed of 6ns. It is a dual bank structure, that is, there are two memory arrays, one of which is ready to read when the CPU reads data, and the two automatically switch each other, which doubles the access efficiency. And the RAM and CPU are controlled at the same clock frequency, so that the external frequencies of the RAM and CPU are synchronized, and the waiting time is cancelled, so the transmission rate is faster than that of the EDO DRAM 13%. SDRAM adopts bank storage structure and burst mode, which can transmit a whole piece of data instead of a piece of data.
DDR RAM (double data rate):
Twice the data speed. Its speed is twice that of SDRAM, and its core is based on SDRAM, but its speed and capacity have been improved. Compared with SDRAM, it uses more and more advanced synchronous circuits. And adopted.
Delay locked loop
A DataStrobe signal is provided. When the data is valid, the storage controller can use this data filtering signal to accurately locate the data and output it every 16 times. DDR can double the speed of SDRAM without increasing the clock frequency. It allows reading data on the rising and falling edges of clock pulses, so its speed is twice that of standard SDRAM.
RDRAM(Rambus DRAM):
It is a kind of memory developed by American RAMBUS Company on the basis of RAMBUSCHANNEL technology. The word length of data storage is 16 bits, and the transmission rate is 600MHz. Pipeline storage structure supports AC * * access and executes four instructions at the same time.
Direct RDRAM:
It is an extension of RDRAM and uses the same RSL, but the interface width reaches 16 bits and the frequency reaches 800MHz, which is more efficient. The single transmission rate can reach 1.6GB/s, and the twice transmission rate can reach 3.2 GB/s.
ECC (error checking and correcting):
Is to check mistakes and correct them.
PC 133:
Because Intel P III supports the external frequency of 133MHz, it needs to have corresponding memory bandwidth, so PC 133 appears, its clock frequency reaches 133MHz, and its data transmission rate is1.066 GB/s/s.
Caching:
It is cache, which is divided into first-level cache and second-level cache. It provides a buffer for memory and CPU to exchange data. So most motherboards have cache chips or slots, because the data exchange between them and CPU is much faster than that between memory and CPU.
IDE (Integrated Electronic Equipment):
A disk drive interface, also known as ATA interface. It is a controller interface developed by Compag and Conner*** and produced by Western Digital Corporation. Now it has been widely used as an interface standard. Up to two IDE interface devices can be connected, and the maximum hard disk capacity is allowed to be 528 megabytes. The control line and data line share a 40-core flat cable to connect with the hard disk interface card. The data transmission rate is 3.3Mbps-8.33Mbps.
EIDE (enhanced IDE):
It is a necessary standard interface for motherboards above Pentium. Two EIDE interfaces can usually be provided on the motherboard. EDIE is integrated on the motherboard above Pentium.
Raid:
Commonly known as disk array, it has two main purposes, one is data mirroring, or data security, and the other is to speed up access. It is often heard that RAID 1 refers to the backup function, RAID 0 refers to the acceleration function, and RAID 0+ 1 refers to both. In layman's terms, it is the backup and acceleration function.
ULTRA DMA/66:
Is a hard disk interface specification, its burst data transmission rate is 66MB/S, which can reduce the workload of CPU and improve the overall system efficiency.
ATA 100 interface:
It is an interface standard with an interface transmission rate of 100MB/ s and 80-pin interface cable, including 40 ground wires, which can avoid electromagnetic interference when sending and receiving data. ATA 100 is completely traditional IDE in backward compatibility, including PIO, ATA/33, ATA/66, etc.
PCI bus (peripheral component interconnection):
Belonging to local bus is a bus structure introduced by PCI group. The data transmission rate is 133MB/S, the load capacity is strong, it can support 10 peripherals, and it is compatible with ISA and EISA buses.
AGP slot (accelerated graphics port):
This is a bus structure aimed at improving video bandwidth. It directly connects the graphics card with the chipset of the motherboard for point-to-point transmission. But it is not an ordinary bus, because it can only connect with AGP graphics cards, so it is not universal and extensible. Its working frequency is 66MHz, which is twice that of PCI bus, and it can provide 528MB/S data transmission rate for video equipment. So it is actually a superset of PCI.
AGP 1X/2X/4X:
The bus transmission rate of AGP 1X is 266MB/s, and the working frequency is 66MHz. The bus transmission rate of AGP 2X is 532MB/s, the working frequency is 133MHz, and the voltage is 3.3V V. The bus transmission rate of AGP 4X is 1.06GB/s, and the working frequency is 266.
AMR (audio/modem Riser sound card/modem card):
Is an open industrial standard, which defines an expansion card that can support voice and modem functions. Through this design, the cost can be effectively reduced, and at the same time, some functional limitations of voice and modem subsystems can be solved.
CNR(communicationnotwork Riser communication network card):
It is an upgraded product of AMR. From the appearance, it is slightly longer than AMR, and the two pins are different and incompatible. CNR can be connected to a dedicated CNR-Modem or use a dedicated home telephone network (home PNA), which has the plug-and-play function of PC 2000 and supports the function of10/1000 MB LAN more than AMR.
Advanced communication riser:
It is an upgraded product of CNR, which can provide local area network, broadband network, wireless network and multi-channel sound processing functions, and is compatible with AMR.
SCSI (Small Computer System Interface):
Small computer system interface is an interface standard issued by American National Standards Institute (ANSI). SCSI was originally defined as a universal parallel SCSI bus. SCSI bus itself does not communicate directly with devices such as hard disks, but establishes contact with devices through controllers. An independent SCSI bus can support at most 16 devices and is controlled by SCSI D.
USB (universal serial bus):
It is not a new bus standard, but an input/output interface standard for connecting computer systems to peripheral devices such as keyboards, mice and printers. ). It is a new serial interface jointly developed by IBM, INTEL, NEC and other famous manufacturers. It is connected by a daisy chain. It consists of two data lines, a 5V power line and a grounding line. The data transmission rate is12mb/s.
FDD:
Slightly shorter than IDE slot, specially used for inserting floppy drive.
Parallel port:
It is the so-called print port. In fact, it can not only connect printers and mice, but also connect modems, scanners and other devices.
COM port:
Motherboards usually have two COM serial ports. Usually used to connect a mouse and communication equipment (such as connecting an external modem for data communication).
PS/2 port:
This is a mouse/keyboard interface. Generally speaking, the round mouse is connected with PS/2 port.
Interrupt request:
Interrupt request. Peripheral is used to send interrupt request signal to computer.
ACPI power interface:
It is a new function unique to motherboards above Pentium. The function is to save energy as much as possible when managing various components inside the computer.
AC’； 97 specifications:
Because the sound card is more and more expensive, and the processing power of CPU is more and more powerful, Intel issued the AC97 standard in 1996, which removed the most expensive DSP (Digital Signal Processor) in the sound card, and made the CPU responsible for signal processing by writing a driver specially, which required some CPU resources when working.
Temperature detection:
If the CPU temperature is too high, the system will be unstable or even crash, so it is very important to detect the CPU. When the CPU temperature exceeds the safe range, it will send out warning detection. There are two kinds of temperature probes: one is integrated in the processor and supported by *BIOS; The other is external, which can be seen on the motherboard, and is generally a thermistor. They all change their own resistance values through the change of temperature, so that the temperature detection circuit can detect the change of resistance, thus changing the temperature indication.
Third, memory articles
Memory is also an important accessory in computer system. Its quantity and quality directly affect the performance and stability of the whole system. Today, I will introduce you to several main parameters of memory, hoping to get help when you choose and use memory.
Synchronous dynamic random access memory (SDRAM);
It is a widely used memory type in PC 100 and PC 133 specifications. At present, its bandwidth is 64 bits, the voltage is 3.3V, and the highest speed of the product can reach 5ns. It uses the same clock frequency as CPU for data exchange, and its working frequency is synchronized with the external frequency of CPU, so there is no delay and waiting time.
Double data rate SDRAM (DDR SDRAM):
Also referred to as DDR for short, because it can transmit data on the upper and lower edges of the clock trigger edge, the bandwidth can reach 2. 128GB/s even at the bus frequency of 133MHz. DDR does not support LVTTL with 3.3V voltage, but supports SSTL2 standard with 2.5V It can still use the existing SDRAM production system, and its manufacturing cost is slightly higher than that of SDRAM, but it is still much lower than that of Rambus. Because the equipment for manufacturing ordinary SDRAM can produce DDR memory with a little improvement, there is no patent problem, so it represents the memory development direction that can compete with Rambus in the future.
Direct Rambus DRAM (DRDRAM):
It is the future development direction of memory advocated by Intel. According to the characteristics of high clock frequency, RISC (Reduced Instruction Set) is introduced into it to simplify the data volume of each clock cycle. The working frequency is higher than SDRAM (not lower than 300MHz), but the data channel interface bandwidth is low, only 16 bits. When the working clock is 300MHz, Rambus uses the upper edge and the lower edge of the clock to transmit data respectively, so its data transmission rate can reach 300×16× 2/8 =1.2 GB/. It is different from the traditional DRAM in that the pin definition will change with the command, and the same set of pin lines can be defined as address lines or control lines. Its pin count is only one-third of that of ordinary DRAM.
Virtual channel memory (VCM):
It is a memory standard supported by most of the latest motherboard chipsets. VCM is a new type of "buffer DRAM" developed by NEC Company, and this technology will be used in large-capacity SDRAM. It integrates the so-called "channel buffer", which is configured and controlled by high-speed registers. VCM not only realizes high-speed data transmission, but also maintains high compatibility with traditional SDRAM, so VCM memory is usually called VCM SDRAM. The difference between VCM and SDRAM is that data can be submitted to VCM for processing whether it is processed by CPU or not, while ordinary SDRAM can only process data processed by CPU, which is why VCM processes data more than 20% faster than SDRAM.
CL(CAS delay):
It is the delay time of CAS, the reaction time of vertical addressing pulse, and one of the important signs to measure the memory supporting different specifications at a certain frequency. For example, at present, most SDRAM (when the external frequency is 100MHz) can run in the mode of CAS Latency = 2 or 3, that is, the delay time of reading data can be 2 clock cycles or 3 clock cycles.
tCK(TCLK):
Is the system clock period, representing the maximum frequency at which SDRAM can run. The smaller the number, the higher the frequency that SDRAM chip can run. For an ordinary PC 100 SDRAM, the logo "-10" on its chip means that its running clock cycle is 10ns, that is, it can work normally at the external frequency of 100MHz.
TAC (time from CLK):
Is the maximum number of input clocks at the maximum CAS delay. The specification of PC 100 requires that when CL=3, tAC should not be greater than 6ns. Some numbers of memory numbers represent this value. At present, the access time of most SDRAM chips is 5, 6, 7, 8 or 10ns.
For the memory of PC 100, when CL=3, the value of tCK should be less than 10ns, and tAC should be less than 6ns. Generally, this formula is used to calculate the total delay time: total delay time = system clock cycle × number of CL modes+access time (tAC). For example, the access time of PC 100 memory is 6ns, and we set the number of CL modes to 2 (that is, CAS latency =2), so the total latency = 10ns×2+ 6ns= 26ns, which means that if the memory of PC 100 and PC 133 is only 6ns.
Sorry, javascript support of the browser must be turned on to browse properly.
Verb (abbreviation for verb) hard disk article
Hard disk is an important storage of computer. Our data, materials and files are all stored in hard disk.
There are not many hard disk manufacturers, mainly IBM, Maxtor, Seagate, WesternDigital, and a Quantum, but it has been acquired by Maxtor.
The performance parameters of hard disk include capacity, storage capacity per disk, speed, cache, internal and external transfer rate, transfer mode, seek time, etc.
Except IBM's hard disk can hold 5 discs, other manufacturers' hard disks can only hold 4 discs. At present, the storage capacity of each hard disk is 15G and 20G, so we can know that a hard disk can reach more than 80G. So the hard disk we bought should also be above 20G, so what is the concept of 20G? Why not 500 Jin? Not 7000 taels? Let's have a look. 1G= 1000M, 1m = 1000m, 1K= 1000 bytes. 1K can store 500 Chinese characters or 1000 English letters.
At present, the speed of hard disk is divided into 5400 rpm and 7200 rpm. Speed is good, but it also has a high calorific value. But now that the technology is much more mature, this problem is no longer a problem.
We extract data from the hard disk and write data from the hard disk through the cache. The size of the cache is an important parameter of the external transmission rate of the hard disk. The bigger the cache, the better. There are three types of hard disk caches: 5 12K and 1M and 2M.
The transfer rates inside and outside the hard disk are inconsistent. Generally, the internal transfer rate is 35M~50M, and the external transfer rate is 66M~ 100M. The speed of writing data into the hard disk is the internal transmission rate, and the speed of sending data out of the cache is the external transmission rate.
Transmission mode:
Mainly divided into AIA-66/ 100. Backward compatibility with ATA-66. Theoretically, ATA- 100 should be faster than ATA-66, but this is not the case. Because the internal transmission rate of the hard disk is low. It seems that we have to pull 400 kilograms of goods at the same speed as a 500-kilogram truck or a 1 ton truck. The only way to improve the internal transmission rate is to increase the storage capacity per disk, improve the circuit board design of hard disk and increase the speed of hard disk.
Looking for time:
The time required for a magnetic head to find data on a disk. The unit is nanosecond (ms), generally 8.2 ms ~ 12 ms, and the smaller the number, the better.
Hard disk design life is generally 5 years, and the warranty is one year.
International business machines Corp.
IBM is the pioneer of hard disk, and other hard disk manufacturers adopt GMR heads produced by IBM. Hard disks include the second generation Longteng series, 7200 rpm and 2M cache, ATA- 100. The storage capacity of each disk is only 15G, but they are all made of glass disks, which makes the magnetic head closer to the disks, faster, and less noise and heat. It is the best hard disk at present, but the price is the most expensive among many brands.
WesternDigital (western digital)
Western Digital (hereinafter referred to as WD) is a famous brand in Europe and America, and it is also my favorite hard disk. WD has many records in the field of hard disk.
The first one proposed IDE interface, which is still in use today.
The first hard disk with ATA-66 interface,
The first hard disk with 2M cache,
The first to introduce a 7200 rpm hard disk with a storage capacity of 20G per disk,
The first hard disk with IEEE- 1394 high-speed serial bus.
WD hard disk circuit boards are all inverted, which reduces the external volume of the hard disk and is the best design for protecting precision circuits. I have used all brands of hard disks, and I feel WD is the best, and it starts quickly. Hard disk defragmentation with the same capacity is more than 20% faster than other hard disks, with low noise and heat generation.
In 2000, Intel demonstrated a PC system known as the fastest Windows platform in the world at IDF-2000 Forum, which took only 18 seconds from startup to shutdown. The system uses WD hard disk, which can be started at full speed in 4.5 seconds.
WD's hard disks are divided into Caviar and Protege, both of which are 2M caches, each of which stores 20G, and ATA- 100 interface, with the former 7200 rpm and the latter 5400 rpm. WD is not expensive, but it is not widely publicized in China, so its popularity is not high.
Seagate
Seagate mainly includes five generations of U series and cool fish series. Cool fish is divided into two, two-100 and three. U-series is 5400 rpm/1M cache, each disk stores 20G, and ATA- 100 interface. Cool fish series all have 7200 rpm and 2M cache, and the storage capacity per disk of II and II- 100 is 100, that of III is 20G, that of II is ATA-66, and that of II- 100 is ATA- 100.
Maituo
Also known as diamond hard disk in China, there are mainly star diamond generation and gold diamond generation, and now there is a beautiful diamond. Drilling around makes my hair dizzy. American diamond, star diamond and gold diamond are all ATA- 100 interfaces, with 2M cache, 5400 rpm for American diamond and 30G for single disk storage. Star Diamond 5400 rpm, 20G storage per disk. Gold diamond 7200 rpm, each disk storage 15G.
Diamond hard disk is my dislike hard disk. Slow speed. It takes 3 minutes to partition 20G hard disk with Fdisk, and only 30 seconds for WD. It is recognized that the diamond hard disk has a high calorific value, and now even the noise is coming from behind. Defragmentation with Windows disk is very slow.
Diamond hard disk is also very particular about power interface, which is easy to burn out. Among many hard disks, the diamond repair rate is the highest. Some people may say that the service of diamonds is good. I totally agree. If its repair rate is not high, how can we know that its service is good?
The current hard disk 100% supports ATA- 100, but the cache is uneven. 7200 rpm is definitely faster than 5400 rpm, but in fact we don't feel it in ordinary applications. ATA-66 and ATA- 100 half a catty. It is recommended to buy WD hard disk with 5400 rpm or more, 2M cache and ATA- 100 interface.
Fourth, the graphics card
There are all kinds of graphics card products on the market now, and the performance and price are also different. For people who don't know much about graphics card products, choosing a graphics card is really a scratching their heads. At this time, people may go online to find some articles to help them choose a graphics card product. However, usually this kind of articles are full of graphics card terms. If you don't understand these terms first, even if you read the article, I'm afraid you don't know why. Therefore, I will simply introduce some terms of graphics cards to you today, hoping to help those who want to know more about graphics cards.
Generally speaking, a home graphics card has several key parts, namely GPU, video memory, BIOS, VGA socket, bus interface and so on. The rest are some patch resistors, capacitors, regulated MOS transistors, chokes, video output, and processing chips that realize some special functions. These will vary depending on the manufacturer, graphics card type, graphics card performance and even graphics card price.