Performance on i875P Based Mainboard
First of all, we decided to figure out with what memory timings and frequencies the new Corsair memory modules could actually work if used in an i875P based mainboard. Note that Corsair TwinX1024-4000PRO undergo all in-house testing for the ability to work at 250MHz (500MHz DDR) on this particular mainboard, and to be more exact on ASUS P4C800.
During this benchmark session we used the following system:
- Intel Pentium 4 2.4C GHz CPU;
- ASUS P4?800 mainboard on i875P chipset;
- Corsair TwinX1024-4000PRO 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.
We tested the stability by running 3DMark2001 SE and 3DMark03 test sets, which load the memory subsystem really heavily. We also used a special Super Pi utility, which is capable of crashing down even the most stable and reliable systems.
The graph below shows at which frequencies, timings and voltages Corsair TwinX1024-4000PRO memory works stably enough in the above described system. During the test session we synchronously increased the FSB frequency and memory frequency (the maximum for our CPU was 280MHz) until the system turned unstable because of the memory subsystem errors. The AGP/PCI frequency was locked at 66/33MHz. The Performance Mode parameter was set in Turbo, and Performance Acceleration Mode – in Enabled position. However, the test results showed that none of these options had any effect on the top working frequencies of the tested memory modules.
Now let’s analyze the obtained results. As we see, with aggressive 2-2-2-5 timings, Corsair TwinX1024-4000PRO modules are unable to work at all (here I am talking about the frequencies of 200MHz and up). In fact, this is not at all surprising. In our article called Choosing Optimal Memory to Match Intel Pentium 4 Processor we have already pointed out that the memory modules capable of working at higher frequencies, and DDR500 definitely belongs here, cannot work with aggressive timings even in DDR400 mode. Now we see another proof of this point. Actually, for those users who are going to use their memory in DDR400 mode with aggressive timings, Corsair offers an alternative memory modules set: TwinX1024-3200C2PRO.
When we reset the timings to 2-3-3-6, Corsair TwinX1024-4000PRO starts working at pretty high frequencies reaching 225MHz with 2.75V Vdimm. The next qualitative improvement is observed when we change the timings to 2.5-4-4-8. In this mode the modules reach 256MHz working frequency. With the nominal 3-4-4-8 timings the result is about the same: the maximum working frequency for these modules reaches 257MHz. Note also that the 257MHz result is not that high at all: it is only 7MHz higher than the nominal. Although no one promised that Corsair TwinX1024-4000PRO will overclock well above the 250MHz, it is still a little disappointing that it wouldn’t. for example, the recently tested OCZ EL DDR PC-4000 Dual Channel memory managed to overclock to 261MHz. Probably Corsair modules are paying back this way for the additional circuitry used for the colorful LEDs.