# few Qs about i7 950



## deviess (Apr 7, 2010)

Hi everyone!

I've been fiddling with my overclock recently, here's what i've figured out:

I can get a stable OC at 3.84GHz with Vcore at 1.275V (160 x 24)
I can get a stable OC at 4GHz with a Vcore at 1.35V (200 x 20) temps started getting a little high so i decided i wouldn't keep it)
I can get a 4.2GHz (untested stable) at 1.375V (200 x 21)

is the increase in voltage for the 160MHz worth it or should i jsut go down to 3.84GHz?

Also, when in the settings for the stable 3.84GHz, why does everything show 3.68GHz rather than 3.84, other than cpu-z and the bios? I ran cinebench and i got a good score at 3.68GHz rather than 3.84GHz. why is this?

After a 3.80GHz OC i found that the CPU scored higher on the (according to cinebench) 3.68GHz OC why is this? kinda confused....


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## Aus_Karlos (Mar 10, 2007)

Make sure that in the BIOS power save modes C1, C2 and C3 are disabled. These can affect the overclock and lower the clock speed when CPU isn't fully utilised and can lead to instability. 
Also ensure that Intel Turbo Boost for the I7's is set to normal and not Turbo. you may find the M/B will increase the core speed when all cores hit 100% usage. Very bad when a CPU is already OCed :grin:.


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## llacrossedude7 (Jul 31, 2009)

You can easily run a safe 3.6-3.8GHz on those voltage as long as you have a solid cooler. Since the i7's have Hyperthreading you should get really great performance.


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## deviess (Apr 7, 2010)

OK, C1E, C2, C3 and C4 are all disabled. Turbo and speedstep are both disabled and already were but conebench etc still says 3.68GHz when i'm watching in relatemp it shows 3.84GHz. My OC that i thought was stable obviously wasn't.

I reformatted for a number of reasons, one being to try and fix my GPU (6970) drivers, another being that I had too much crap on that OS. Thing is, I still get crashes for some reason.

I ran Prime95 on my old OC and after a couple of hours there was one error on one of the cores. So I downclocked again to the stock settings, and last night, before I went to sleep, I set Prime95 going again.

Woke up this morning to another error on one of the cores/threads... I don't understand how I get an error at stock... Why might it be?

The other question I have is this: Why the hell did one core get 100 more tests done than the others?


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## deviess (Apr 7, 2010)

Sorry should've said earlier! here's my specs so you know what i'm working with:

ASUS P6X58D-E
Core i7 950 @3.07GHz
12GB Corsair XMS3 @1600MHZ
Corsair TX650W (Voltages all seem stable when running prime95 and furmark when OCed)


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## Wrench97 (May 10, 2008)

Try backing the ram down to 1333 and rerunning the test at stock CPU settings.


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## deviess (Apr 7, 2010)

ok, will run that later. the BIOS is running the RAM in XMP mode so it should be at the rated voltages and speeds etc, which it does.

anyways, I will downclock it later then run prime95 overnight again.


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## deviess (Apr 7, 2010)

Ok, Prime95 ran fine all night. just under 9 hours it went for and every test passed on all threads. is it something to do with my RAM?

My BIOS settings were actually all on auto so is it possible that the RAM wasn't geting 1.6V or somethign and it caused instability?


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## Wrench97 (May 10, 2008)

It's something I've been finding on 1600 speed ram, most seem to run more stable and seem to be more nimble at 1333 then 1600, remember 1600 is a overclock speed as native for the on CPU controller is 1333.


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## deviess (Apr 7, 2010)

hmmm. ok. what about 2000 then? anyways. if i leave my RAM at 1333 or thereabouts, will the speed of my RAM be fine. and what speed should my uncore clock be? last night i had it run at 3200 and it was fine. but that's what it was at 1600MHz RAM. shoud it be 2666 for the lower speed?


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## Wrench97 (May 10, 2008)

I've yet to see 2000 run that fast on any CPU but a Extreme Edition, usually it's setting the uncore higher that causes the errors, as it raises everything but the core speed PCU, QPI, memory, L3 are all controlled by the uncore speed.


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## deviess (Apr 7, 2010)

so if i leave my uncore at 3200MHz everything should work fine? and keep the RAM at 1333? then try and OC the CPU again and it will work nicely... in theory?


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## Wrench97 (May 10, 2008)

You'll have to play around to find the sweet spot on your particular CPU, RAM and MB they're not all the same once you start to OC, try settings in the middle or lower the uncore to stock and up the blck.


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## deviess (Apr 7, 2010)

well i just set it at 162 blck with the ratio at 24 now i ahve RAM at just under 1300 and uncore was at just under 2600 i think. gonna run prime95 now and see what happens.


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## Wrench97 (May 10, 2008)

If it comes out good up the uncore and rerun.


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## deviess (Apr 7, 2010)

ok. that didn't come out good. put blck back to 160 how it used to be and the RAM and uncore are both whatever their respective MHz are; pretty much the same.

It stable so far. but i will probably leave it running overnight again to see what happens.

also, should i try and run the RAM at 1600 or shuold i leave it at 1300-ish? will the performance difference be that noticable? especially in things like blowing up tnt in minecraft where i might blow up 100k tnt at once... would that benefit from the exrta 300MHz?


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## deviess (Apr 7, 2010)

AHA! think i may have found the problem!

My RAM is rated at 9-9-9-24 but in the BIOS it was set to 8-8-8-20... no idea how or why, but that is something a bit off and is probably the cause of it. I have gone back to my old settings at 3.84GHz and 1604MHz. should be good now so I'll run prime95 overnight again and see if it has been fixed.


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## Aus_Karlos (Mar 10, 2007)

Your motherboard has different presets when it comes to RAM frequency and timing. Usually RAM at 1600mhz will be at 9-9-9-24. But dropping the frequency while leaving the RAM timings on Auto will cause them to Tighten ([email protected] 1333mhz). Think of it as a compensation, you have less latency between RAM-CPU but at the cost of some bandwidth. To be honest i was running my RAM at 2000mhz and saw no benefit. Its better to reduce frequency and tighten timings.


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## deviess (Apr 7, 2010)

OK. Well, I downclocked my CPU to 3.2GHz 160 x 20 and it ran for 16 horus straight no problem on prime95 so i think i may just leave it there. I might put an extra 1 or 2 on the multi but if i do that it seems to be less reliable.

RAM is working fine to the looks of it, so hopefully that's sorted.

Only problem I have now is my GPU.... Damn AMD drivers. They don't work properly. 6970 if you want to know.


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## Wrench97 (May 10, 2008)

What kind of issues?

Make sure MS .net is the latest version.

Sometimes I use driver sweeper to completely remove the driver and reinstall or move back to the last driver sometimes works.


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## deviess (Apr 7, 2010)

This is on a fresh install of windows. It may have been the RAM and CPU that were failing... but it would seem far more likely the graphics card. A shutter blind style screen of one colour comes up sometimes when the cpmuter crashes which seems grpahics orientated.

Anyways, I'm using the latest off the site which is 11.5 and I don't like CCC as it just makes it crash far more. so it's just the driver installed.

Does ms .net thing have an impact on graphics cards etc?


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## Wrench97 (May 10, 2008)

The ATI driver uses .net for some of the interface framework, CCC is based on .net.

The color and blind effect is usually a failing video card but not always.


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