For whatever reason, my sticks of CORSAIR XMS2 2GB (2 x 1GB) DDR2-800 are showing up in CPU-Z's SPD section as 4-4-4-12 at stock voltage (v1.9 I presume), but my Patriot eXtreme Performance 2GB (2 x 1GB) DDR2 800's are showing up as 5-5-5-15. According to the specs of the Corsair, 4-4-4-12 is achieved at 2.1v, whereas the Patriot's achieve 4-4-4-12 at 2.2v. So, despite the differences in voltage suggestions:
1. Must I change my DDR2 voltage to see the right timings for all four DIMMs? And should I go to v2.1 or v2.2?
2. Why do the Corsair run at the right timings automatically, but not the Patriots (both have EPP support)?
3. Do I need to touch the memory multiplier or FSB/Core voltage settings to achieve 4-4-4-12 across all four DIMMs?
I had the same problem with my g-skill DDR2-800. My Gigabyte motherboard's bios though allowed me to change the clock timings from 5-5-5-15 manually to 4-4-4-12. It now shows up in CPU-Z as 4-4-4-12. The problem for me though is that it still says its 1.8v in CPU-Z when I know that I set it to 2.0v in the bios. I think it just doesn't show the correct voltage in CPU-Z or the bios isn't allowing my ram to run at that voltage or something...
1.) Not necessarily. You could perhaps achieve the same timings with lower voltage. Pick what is stable.
2.) The SPD charts of CPUz is not what the ram is running at. You'll have to look else where. And you do need to set the settings in the bios manually.
3.) I don't think you need to touch the vcore or the FSB voltage to OC ram, unless you're OCing both the mobo and CPU as well. You also do not need to change the system memory multiplier, most people leave it at 2 since it supposedly offers the best performance.