Intel Core 2 Duo E8400 CPU
Asus P5K64WS motherboard
XFX geForce 8600GT Superclocked
SilverStone Decathlon DA800 800 watt PSU
1 x 250 gig Seagate SATA 3.0 HDD
OCZ Vendetta CPU Cooler
Zalman VF-700Al GPU Cooler
Microsoft Windows Vista Ultimate 32-bit
Besides overclocking, I feel that it is important to test memory modules for their flexibility. Some may not have the hardware to attain significant overclocks, but they still can realize a performance boost by tightening timings. Normally, I would also experiment with lower voltages, as most high-performance memory modules I have had defaulted at higher voltages, but the Xtune runs at 1.5v, which is the standard for PC3 memory.
At default, Xtune runs at DDR3-1333 8-8-8-24, at 1.5v. Looking at the SPD chart, we see timings of 5-6-6-16 at DDR3-834, 6-6-6-18 at DDR3-1000, 8-9-9-25 at DDR3-1333, and 9-9-9-27 at DDR3-1500. Notice that the VDIMM is the same across the chart, the Xtune plans to do it all at the stock voltage. Prior to benchmark testing, I ran MemTest86, the Xtune showed no errors.
The first testing I will do is to tighten the timings. I spend some time experimenting, I could not get the Xtune to boot at CAS5 at any frequency. Understandable with CAS8 memory. The best timings I could get were 6-5-5-9, and it held rock stable up to DDR3-1000. Increasing VDIMM made no difference. I found those timings not great but respectable enough that would get someone a noticeable performance boost with a motherboard or processor that maxes at 1000 FSB.
Next I do some overclocking. After a lot of experimentation, I feel that the memory has pretty much maxed out at DDR3-1528, with timings of 10-10-10-25. I started getting blue screens with memory dumps at much above that. I upped the VDIMM, but it really didn't help any. I thought that the DDR3-1528 clock was pretty stable, but we'll see later that DDR3-1500 was a much more stable clock.