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Overclocking

For all intents and purposes, the Corsair XMS2-PC8888 is already significantly overclocked.

JDEC standards were only supposed to go as high as DDR2-800 (PC6400) however memory manufacturers have long ago significantly exceeded those limits. JDEC really should set standards up to at least PC8500 as most major manufacturers have products that run at least that fast.

The fact is, that the PC8888 memory is already running "close to the edge" is bourne out by it not being able to run at 1111-4-4-4-12 on the excellent Asus P5W DH Deluxe; on that board it topped out at 1066-4-4-4-12 and turned in some amazing numbers. At Corsairs suggestion I tried the PC8888 memory on the newer NVIDIA 680i based Asus P5N32-E SLI motherboard we have in for review, and on that board, the memory was not only able to meet its specification, it was able to exceed it - albeit not by a great margin.

The best result with the Corsair PC8888 was 1131MHz at 4-4-4-12 timing; which corresponds to a PC9048 rating - noticably higher than the PC8888 rating the modules are sold as.

Are there any guarantees that every module will work at that speed?

No.

Heck, I am sure there are some boards out there that won't even run the modules at PC8888 - when all but the latest chipsets were designed, no one thought DDR2 would reach over 1100MHz!

The fact is, running the memory at 1066-4-4-4-12 can outperform running it at 1131-4-4-4-12 - if you have an additional 2MB of L2 cache.

Regardless, should you wish to try 1131-4-4-4-12 on an Asus P5N32-E SLI, here are the settings that worked for me:

• AI Tuning: Manual
• FSB Memory Clock mode: Linked
• FSB Memory Ratio: 5:4
• FSB (QDR) MHz: 1415
• CPU Multiplier: 8
• Memory timing: 4-4-4-12-2T
• Spread Spectrum: Disabled
• LDT Frequency: 4x
• Vcore 1.55V
• Memory Voltage: 2.4V
• HT Voltage: 1.45V
• NB Voltage: 1.4V
• SB Voltage: 1.6V
• CPU VTT Voltage: 1.35V

Be careful if you want to try this; the 680i chipset runs VERY hot - personally I have three 63CFM fans (one on the Noctua 12, two blowing at the chipset) and the fan module that came with the memory all hooked up for these benchmarks!

Conclusion

The Corsair TWIN2X2048-8888C4DF ended up meeting its claimed specifications, and in that, it lived up to the high standards I hold Corsair to after the excellent results I've gotten in the past from their PC8500 and PC8000 modules.

Will another manufacturer make modules that will run faster? Inevitably.

The "performance King" hat regularly gets passed around; and as you can see from the results presented in this article, there are a lot of fine high speed modules out there; and often top-tier memory not sold at the highest speed a manufacturer sells will significantly overclock.

What else can I say? It works, its fast, its good.

Recommended.

Why am I recommending it even though it did not hit 8888 on all motherboards?

Because it simply screamed when the right balance of FSB/CPU/memory speed was achieved, and because I was able to hit a scorching 1131-4-4-4-12 setting. 

Let's face it. As soon as you get any memory that hits 1000-4-4-4-12 you are pretty much laughing. After PC8000 you really are only looking for how easy it is to get it running at 1000MHz+, how far above it you can push the memory if you are lucky enough to have a motherboard and chipset that can handle it, and on how many motherboards it will run at that speed. How high you can push the memory is a good indication of the quality of the stick; and often because of processor or FSB limitations you may still be better off to run the memory at less than its maximum speed - if you can run it with a higher FSB and a higher CPU speed.