The gap between DDR333 and DDR400

Intel has supported dual-channel since 865p motherboards, and early motherboards only supported symmetrical dual-channel, that is, the two memories should be the same.

Memory bandwidth: Memory frequency*4 (32-bit technology in the early days) dual-channel multiplied by 2.

If your motherboard is a motherboard before 865p, the two memory are not the same only downclocked to 333M, which reduces some memory bandwidth, but not much, because it is not multiplied by 2. If dual channels are supported, the performance gain will be greater if it is replaced by two of the same strings, because not only does it run at a frequency of 400m, but it also has to be multiplied by two.

The difference is very small, and the memory of the two DDR generations, no matter which one is outdated. Not only the memory, but also the platform plays a big role, and if the platform is not changed, no matter how strong the memory is, it will be in vain. What's more, the DDR400 is not strong either.

It's more practical to save money to upgrade the platform.

333 and 400 are about the same. The gap between 256 and 512 is similar.

After all, it is DDR1 generation.

Dual-channel can only do this DDR1

The difference between 333 and 400 is about 2% or 3%.

ddr400 ddr400

Frequency: 166MHz 200MHz

CAS latency.

RAS to CAS

Cycle 7 8

Mine is the same as yours, one DDR333256 and one DDR400512 are used together, and the DDR400 is downclocked to 333, which can be seen from the CAS latency cycle, which is much slower

It's huge. The interpolation of 256+512 is itself wrong.

The capacity is increasing, but the speed is greatly reduced.

256 + 256 512 + 512 1g + 1g is the correct interpolation.

1. The specifications are different.

DDR3 memory starts at 800MHz and can reach a maximum frequency of 2133MHz.

DDR4 memory starts at 2133MHz and can reach a maximum frequency of 3000MHz.

2. The appearance is different.

DDR4, as an upgraded version of DDR3, has undergone some changes in appearance.

The golden finger of DDR4 memory has become curved, which means that DDR4 is no longer compatible with DDR3, and if you want to replace DDR4 memory, then you also need to replace the motherboard with a new platform that supports DDR4 memory;

3. The memory capacity is different.

In terms of memory performance, DDR3 can reach a maximum capacity of 64GB per strip, but only 16GB and 32GB are available on the market.

DDR4 has a maximum capacity of 128GB per strip, and the larger capacity means that DDR4 can support more applications. Using DDR3-1600 memory as a benchmark, DDR4 memory has at least a 147% performance boost, and this magnitude is a clear difference.

DDR Formula:

DDRI II memory operating clock frequency: Actual clock frequency*2. (Since two data transactions are transmitted simultaneously, the clock frequency of the 200MHz memory will operate at 400MHz.) ）

Memory bandwidth = Memory speed * 8 bytes

Standard formula: memory frequency dividing coefficient = clock frequency 200 * speed algorithm: external frequency * (except frequency frequency synchronization frequency) (using this formula will result in a 4% error).

The above content reference: Encyclopedia - DDR