How to combine CPU and memory

CPU and memory are the most reasonable (both the CPU and memory have the corresponding speed and bandwidth. In the computer configuration process, the CPU speed and bandwidth are used together with the corresponding rate and bandwidth memory, which will directly affect the performance of the entire machine. Improper combination will often waste CPU or memory performance. Next, we will have a deeper understanding of the common knowledge of CPU and memory matching rules.
1. Obtain the rate and bandwidth.
When we want to match a reasonable CPU and memory, we should first understand the CPU and memory speed and bandwidth respectively. Generally, we can easily understand the CPU frequency of assembly machines, because we have already introduced the CPU frequency in the packing box or in the instruction manual, but the configuration sheet usually only specifies the capacity, for example, the "256 mb ddr" text.
We can use specialized detection software such as Everest to directly test the memory speed. Tip: Everest, formerly known as aida32, is a tool for testing software and hardware system information. It can display details about every aspect of the PC. : Http://www.skycn.com/soft/8258.html.

2. Speed Overview
In the current CPU market, the FSB (Front-End bus) of Intel's three series products are both 100 MHz, and the FSB of the Four series products is 400 MHz, the Pentium 4 series has three levels: 400 MHz, 533 MHz, and MHz. The CPU Front-End bus of AMD's new Poison Dragon series is 266 MHz. The fsb of the athlon XP series based on Thorton core is also 266 MHz, and the fsb of the athlon XP series based on Barton core is 333 MHz, the Barton 3200 + and athlon 64 series products have a MHz Front-End bus. In the current mainstream DDR memory market, ddr266, 333, and 400 memory is the mainstream in the diyer and brand machine markets.

3. bandwidth Overview
CPU bandwidth refers to the data transmission rate between the CPU and the North Bridge. From the calculation method of the CPU frontend bus bandwidth, "frontend bus bandwidth = system external frequency × n times speed × 64-bit bus bit width/8, we can know that the transmission bandwidth of the P4 series 133mhz external frequency, that is, the CPU speed of the front-end bus is 533 MHz (133mhz external frequency × 4 times speed), up to 4.2 Gb/s (533mhz × 8. Therefore, we can calculate the CPU bandwidth of other front-end Bus: the transmission bandwidth of 266 MHz FSB is 2.1 Gb/s, and that of 333 MHz FSB is 2.7 Gb/s; the transmission bandwidth of 400 MHz FSB is 3.2 Gb/s, the transmission bandwidth of 533 MHz FSB is 4.2 Gb/s, and the transmission bandwidth of 800 MHz FSB is 6.4 Gb/s. Memory rate refers to the memory operating frequency. For example, the ddr266 operating frequency is 266 MHz. According to the memory bandwidth algorithm: bandwidth = bus bit width/8 × number of packets exchanged in a clock period × bus frequency, ddr266 bandwidth = 64/8 × 2 × 133 = 2128, and its transmission bandwidth is 2.1 Gb/s, therefore, ddr266 is also known as pc2100, where 2100 refers to its memory bandwidth of about 2100 MB. Similarly, ddr333 operates at 333 MHz, and the transmission bandwidth is 2.7 Gb/s, commonly known as pc2700. ddr400 operates at 400 MHz, and the transmission bandwidth is 3.2 Gb/s, commonly known as pc3200.

4. Impact of speed and bandwidth on computers
We know that the overall performance of the CPU (that is, whether it can truly play, extract all the performance of the CPU) depends on the cooperation of other components of a computer, especially the memory of one of the main components. Therefore, whether the CPU and memory speed and bandwidth work together directly affects the bus speed of data exchange between the two. From the data calculated above, we can find that if the purchased cpu fsb is 266 MHz or less than 266mhz, it is more appropriate to use ddr266. Intel's CPU has higher requirements on memory speed than AMD's. Even for low-end and mid-range ciyang 4 series CPUs, ddr400 memory must be configured to meet CPU needs. That is to say, if you purchase a brand-name host that uses the race Yang 4 series CPU or want to assemble a race Yang 4 computer, you need to configure ddr400 memory, otherwise, the performance of the CPU will not be fully realized due to the memory bandwidth bottleneck (that is, the memory bandwidth cannot meet the CPU bandwidth needs. In addition, the CPU of the 533mhz and 800mhz Front-End bus requires dual-channel ddr266 and ddr400 to be configured properly. However, it is prompted that, in fact, we usually use the brand-name server of the Sai Yang 4 series, with only ddr333 memory. Although this will waste 0.5 Gbit/s of CPU bandwidth, it is only theoretical data, as shown in the test data based on the 533 MHz fsb cpu and the same brand of ddr333 and ddr400 platforms, although the ddr333 speed is indeed inferior to that of ddr400, the difference is no theoretical 15%, only about 7% (for example, ddr333 is 2002 and ddr400 is 13270 in the pcmark 13496 pro of the overall memory read/write performance ), in some testing projects (such as memory latency testing, super π, and quake 3), the performance is almost the same. Therefore, if you have a shortage of funds at hand, you do not have to worry too much about the waste of CPU performance if the configured memory is slightly lower. As far as brand machines are concerned, ddr333 and saiyang 4 are also reasonable in terms of grades and purposes.

5. Works with appropriate computer configurations
To sum up, if you select a four-series CPU, you should configure ddr333/ddr400 memory, ddr266 is only suitable for the CPU of ceyang 3 and the athlon XP series based on the Thorton core products using AMD's new drug dragon. The product of the Barton 3200 + model and the athlon 64 series should be equipped with ddr400 memory. Similarly, if you are buying a P4 series processor, you should use ddr400 or even dual-channel ddr333 or ddr400 memory to match, so as to avoid excessive CPU bandwidth waste and affect the overall performance of the computer. With the above knowledge, we can know exactly how to match CPU and memory when assembling a computer. Of course, if you are buying a brand machine, you can also analyze the rationality of the brand machine configuration from the knowledge above. After all, the current brand machines are diverse in both brand and model types, it is impossible to determine what you have purchased. It is a reasonably configured model. After learning about the rules of these configurations, we can select brand machines of different models and brands based on these rules and select the model with the highest cost performance.