High vDimm and AMD no go

Neuromancer · #1 03-05-2010

Well was wondering why I could not clock my CPUNB with any stability recently. Talked to Buckeye about it, and today I see a post about a guy running 1.65vdimm and not passing blend until he dropped it.

So I pulled out the 1.9v 1600 7-7-7 sticks and dropped in 2 sticks (glad I did not RMA them yet) out of a triple channel kit I picked up recently. (1800 8-8-8 1.65 running 1600 8-8-8 at 1.62)

After not passing blend at 2400 MHz CPUNB (fails in 1 minute) I am now 10 minutes into blending at 2600 CPUNB.

Looks like I am going to try shooting for 3K and see if it opens up any performance on the CPU.

Kal-EL · #2 03-05-2010

Glad to hear you found a new angle.

Neuromancer · #3 03-05-2010

Yup... 11 minutes into a 3000MHz CPUNB blend run.

FACE · #4 03-05-2010

I wouldn't have made it to half that.... call it good @ 5 and push on!

Good stuff.

Neuromancer · #5 03-05-2010

Well I opened up CPUz and AOD to get a screenie... and low and behold its reading 2000 MHz.

Reboot... 3000 MHz get into windows 2000 MHz. WTF?

set it to 2800 and it shows up fine. Trying to run some p95 at 4.4 GHz now, figure if I can make that stable... pushing past 4.6 should not be a problem at all

(EDIT: Looking at the bot, I have no reason to push past 4.45-4.5 benchable at this time unless I move to DIce (which I am on Sunday

)

Buckeye · #6 03-05-2010

As I said when we talked... I have used an older set of G.Skill DDR3 from back in my 790i days that I had vdimm up to 2.1v and that worked fine.

I also use 2 sticks from a 3 stick I7 kit all the time at 1.65vdimm

All should work fine, just make sure the settings in teh BIOS are set correct.

Neuromancer · #7 03-05-2010

Yeah I dunno Bill...only way I could up the CPUNB stable was with the lower vdimm.

I do know even with my 1.9v sticks when I dropped the vdimm I was able to increase the IMC.

Maybe c3 is different or something?

Cecil · #8 05-14-2010

Lower Vdimm causes less stress. Thats why I like the Gskill ECOs. With 1.45Vdimm I can run them at 1600 6-7-6-18 with NB at 2600, CPU around 4.2Ghz.

Going from a 790X-UD4P to a 790XT-UD4P with the same CPU netted me a slightly higher 24/7 stable setting as well. Only difference was vdimm/ram speed/timings.