Before we pass over to the actual analysis of the performance boost you can get due to the new Corsair TwinX1024-4000PRO memory modules, let’s try to figure out what would be the best application for them. As we have just seen, these memory modules can’t work with aggressive memory timings, that is why their major advantage is the higher working frequency. This feature is valuable if you are overclocking your CPU and tend to overclock the FSB and memory frequency synchronously. Besides, it doesn’t make any sense to use Corsair TwinX1024-4000PRO at 200MHz or close, because other memory modules (such as TwinX1024-3200C2PRO) will surely provide much higher performance boost due to lower latencies.
However, 257MHz frequency, which we will be able to achieve with the modules we are testing today, is not that high at all: many Pentium 4 processors can work at a much higher FSB frequency. For example, you can easily overclock a Pentium 4 CPU with 800MHz bus up to 3.5-3.6GHz. This way, it makes much more sense to use Corsair TwinX1024-4000PRO when you overclock your CPU with a 14x multiplier, i.e. during Pentium 4 2.8C overclocking. In this case, increasing the FSB frequency to 250-260MHz allows reaching about 3.5-3.6GHz CPU frequency. The CPUs with lower multipliers are most likely to be restricted by the maximum memory frequency thus requiring the lowering dividers. However, when you apply lowering dividers the memory frequency drops down to around 200MHz, which means that it would be better to use DDR400 with lower latency.
When you overclock a CPU with the multiplier above 14x, the memory cannot reveal all its potential, because the FSB frequency increase will be slowed down by the CPU frontiers. In other words, Corsair TwinX1024-4000PRO, as well as any other DDR500 memory, appears to have very narrow application field.
Now let’s still try to find out what the benefits of Corsair TwinX1024-4000PRO are when used in the most favorable conditions, that is during Pentium 4 2.8C processor overclocking. Here we will compare the performance of two systems:
- One with Intel Pentium 4 2.8C processor overclocked to 3588MHz by raising the FSB frequency to 256MHz and using Corsair TwinX1024-4000PRO memory working in synchronous mode
- Another one with the same processor but Corsair TWINX1024-3200LL memory working with a lowering divider set to 5:4, i.e. at 205MHz.
Note that the result of this testing is not predetermined at all. The thing is that Corsair TWINX1024-3200LL working at 205MHz can allow 2-2-2-5 timings, and in order to make our Corsair TwinX1024-4000PRO work at the desired 256MHz, we will have to use much worse timings: 3-4-4-8.
The test systems in this case were configured as follows:
- Intel Pentium 4 2.8C GHz CPU (overclocked to 3588MHz);
- ASUS P4C800 mainboard on i875P chipset;
- Corsair TwinX1024-4000PRO and Corsair TWINX1024-3200LL memory modules;
- 1024MB RAM, the memory worked in dual-channel mode in all tests due to the fact that we had two 512MB memory modules at our disposal;
- NVIDIA GeForce FX 5900 Ultra graphics card, Detonator driver version 45.23;
- Seagate Barracuda ATA IV HDD, 80GB;
- MS Windows XP Professional SP1.