Question about BIOS, VccSA and VCCIO

[BonzaiDuck]

I had ignored memory over-clocking when I built my i7-2600K last year. It made my work easier, and I got a good kit of DDR3-1600s 1.5V with tight latencies.

Now -- I've come back to it.

I doubled my RAM from 8GB to 4x4GB. I am beginning to suspect that this will require only minor adjustments to voltages for the speed and timings I want.

I did some more "e-search" and reading. Apparently, both VccSA (for the IMC) and VCCIO assist for higher speeds and more slots filled. Other sources suggest "don't mess with VccSA."

But the VccSA setting option is not available on my P8Z68-V Pro with BIOS version 606. I now find it was introduced with BIOS 706. Further explanations indicated that ASUS specifically had linked together VccSA with the VCCIO adjustment for the earlier BIOS versions.

For that reason, I'm hoping I needn't have to update to BIOS 706.

Will I really be "missing out" on something if I can't manually adjust the VccSA setting?

 

[tweakboy]

I got to 2600k and 8 4x4GB and I have no idea what I read. Im sure tho someone will help win.. gl

 

[Cerb]

You might have to run the RAM at 1333MHz (the horror!), or loosen the timings a good bit. Unless all you do is run WinRAR all day, don't sweat it.

 

[BonzaiDuck]

You might have to run the RAM at 1333MHz (the horror!), or loosen the timings a good bit. Unless all you do is run WinRAR all day, don't sweat it.

I don't think so . . .

Some "over-clocking wisdom" suggests that alternate adjustment of "system agent" (memory controller) voltage and the VCCIO termination voltage will stabilize two situations: filling all the RAM slots, or OC'ing the RAM for higher speed.

If ASUS had "linked" the VccSA and VCCIO voltages in their earlier BIOS, it may not be necessary to manually tweak the VccSA. I was looking for more insight . . . on that . . .

Right now, two kits of G.SKILL GBRL DDR3-1600, 9/9/9/24. I was able to run 20 hours of HCI Memtest on the 16GB or nearly 400% coverage before the test failed, at the DDR3-1866 speed and 10/10/10/28. The VCCIO for that test was only 1.076V. That leaves as much as 0.125V of more adjustment in 0.025V increments -- probably with the RAM voltage still set to its 1.5V spec.

So . . . . I don't think I'll have to run the GBRL's as "1333 Mhz RAM." My biggest gripe -- the time it takes to thoroughly test 16GB configurations . . . . Think about it: If it takes 20 hours to complete 40% of an "extremely thorough" test, the test fails, you have to start . . . alll . . . over . . . . again . . .

The temptation is to make sloppy voltage adjustments -- higher than necessary -- to avoid wasting time in the stress-tests. . . .