"QPI / Processor Uncore" voltage

M

Momo

Gawd
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Mar 3, 2005
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Ok, so i'm new to overclocking a core i7.

I've got an intel DX58S0 motherboard, and i've got what appears to be a stable overclock at 3.52ghz, memory at 1.5v, and "QPI / Processor Uncore" (that's what the intel bios calls it) at 1.35v

Is 1.35v safe for the "QPI/Processor Uncore"?
If i drop this voltage at all, keeping the clocks the same, it becomes unstable within windows.

My temps dont go over 80 celcius under full load (running P95, 8 threads) .... when gaming they dont go over 60 celcius it seems.

Any help here would be greatly appreciated. I like the stable OC, but I dont want to shorten the life of the processor / motherboard. The processor core voltage itself is still stock IIRC.

Anyone know a good program that can tell me all this info in windows 7 64-bit accurately? ... I was using the Intel Desktop Control Center (not supported for windows 7 yet, they are working on it now though, confirmed by intel tech support last night)
 
Are you using auto vcore voltage? At 3.6ghz i was running 1.18 vcore set in bios manually with qpi at 1.2125, ive now upped my bclk to 183x21 (turbo enabled) vcore at 1.2750, qpi at 1.300, memory voltage at 1.64. Id suggest using manual voltages particularly for qpi and vcore, this way you can se them a bit lower which will help with temps. Btw, 1.35 qpi is the max reccomended.
 
here's a what my motherboard has in terms of voltage adjustments.
CPU Core: Either static from 1.0000V to 1.6000V (in 0.0125V increments) or dynamic from +0.000V to +0.489V
CPU Uncore & QPI(...commonly called CPU VTT...)I: 1.150V to 1.800V (in 0.025V increments)
Vdimm: 1.50V to 2.50V (in 0.04V increments)
IOH (Northbridge): 1.100V to 1.500V (in 0.025V increments)

Will setting the CPU core to static at a level where it's stable now allow me to lower the CPU Uncore / VTT voltage ??

link to source for mobo info: http://vr-zone.com/print/5-way-x58-motherboard-roundup-part-1/6298.html

sorry, it's set to default not, which is dynamic.
 
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ok so i tried the manual voltage for cpu core, with QPI/Proc Uncore at 1.25, and it would not get me to my desktop as high as 1.1875 ... should I keep trying higher? how high?

I did however discover that 1.325 is stable for QPI/Proc Uncore... so that's a little less voltage. I really wanna get that number down though, i don't like the idea of increasing voltage to the limit, I want my components to last...

Thanks for your help all!
 
Well, Im using the same board and Ive found that too much QPI causes me instability. Also, QPI generates more heat than vcore (ie: Id see more difference in temp lowering my QPI 1 notch than dropping vcore 2 notches).

For 4.2ghz, Im running 1.2v QPI, 1.15 IOH, and 1.3v (bios, 1.254v actual) vcore. Also, your instability may be from your vDimm. Its only 1.5 and Im pretty sure MOST ram runs at 1.65v default. Try setting your ram to 1.66v in the bios. Id almost bet money that is causing the instability and not so much teh QPI voltage.
 
i read that more than 1.5v for RAM can damage the processor? i swear i read this right on intel's website... is this outdated info?
oh, nevermind... it shows 1.6V. I will try setting the vDimm to 1.6 i guess.

Before i do though... i'm using Mushkin part #998659

For some reason, i thought this ram was rated for 1.5... when it's really 1.5v-1.6v

I will try lowering the QPI, and raising the vDimm. will get back to you in a few mins
 
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well, with ram set to 1.58v, and with the current OC (160x22 for 3.52), the system will not even POST with QPI @ 1.2v ...

Doz, do i set the voltage for Vcore manually now?
 
man, i'm getting nowhere with this. It wont POST with the previously stable overclock, now.

I set all the performance stuff back to default for Processor and Memory.
 
Ok... Just throw these settings in and give it a shot...

Bclk set to 200mhz, Multiplier set to 20x
Turn off turbo/eist/c1e/speedstep for now (you can enable 21x multi full time with this board though!)
CPU vCore: 1.35
QPI: 1.225
IOH: 1.175
Set your ram divider to 2:8 (important!!) and set the uncore to 16 (always 2x the divider, you may need to adjust it after a bclk change so always check it).

Now, what you MIGHT be doing wrong is when you change your bclk, are you adjusting the ram divider? You will raise the FSB and the divider might stay at 12, which would cause your ram to be clocked too high. Maybe not, not sure. The UNCORE and the ram divider can easily make a system not post. If you DONT change it, that could very well be your problem.

BTW are you using a D0 cpu or C0? Above would be for a D0 and C0 might change things. Give it a shot and report back. If that doesnt work, go the old fashioned route. Find your max bclk w/ the lowest multi possible then slowly up it.
 
thanks for the post Doz.
When you say turbo/eist/c1e/speedstep... these are all basically the same thing, right?
I turned off turbo, and the cpu idle power state option, but couldnt find speedstep or c1e.

I've booted with the settings above, 4ghz! ... ok, so i ran prime95, and it immediately jumped to ~86 celcius. Im going to try backing it off a bit.
 
Definitely try to lower the vcore, that was just a round about high shot in the dark to get you started. Also, try turning off hyper-threading if you dont need it. It will lower temps by ALOT.
 
so, I tried dropping vCore to 1.230 and QPI / UnCore to 1.175 ... running blend now, temps hovering from 80-85 ...

You said QPI ups/downs had a greater effect on temps then vCore eh ?

Gonna drop unCore some more, see if it will boot. I want those temps to stay around 80 under 100% load, not 85+
 
vCore down to 1.219 in CPU-z, i swear i set it to 1.300 in BIOS... is there a setting i've missed that is lowering that voltage or something?

QPI is down to minimum now, seems stable. 1.150... i think i had the QPI multiplier too high before, that was the problem.

Gonna try dropping vCore a bit more.
 
I've gotta keep dropping the voltage to find out how low i can take it, at 3.8, to keep the temps down. Gonna take some time i think.
 
Hey doz, i stress tested overnight at 3.6 (1.2000v vCore, min QPI, and stock IOH i think) and it passed.

I recorded 1.200v in BIOS, and 1.125v in CPUZ with 100% slope.
I recorded 1.200v in BIOS, and 1.148v in CPUZ with 50% slope.

Seems i've got 0.075v Vdroop? Am i reading this correctly?
Like i said though, it was 100% stable running prime95 overnight, and I was happy with the max temp of 75 celcius. So... how to proceed? this is 200.2Mhz x 18.0 for 3.603.2Mhz btw.

Keep the 50% slope and try a 19x multiplier (3.8ghz) ?
Drop the voltage another step and check for stability?

... I really dont want to 'over volt' the CPU, as iirc this decreases it's life more so than overclocking.
 
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