i7 950 OC Oddity

A

Arthur Hucksake

Limp Gawd
Joined
Oct 27, 2010
Messages
373
Hi folks,

Recently switched to a pair of 570 GTXs SLI and started getting stability issues, first point of call was to blame the cards as the BSODs I was getting pointed towards video drivers and VIDEO_TDR errors.

CPU was OC'ed to 3.7Ghz and had been stable for sometime.

Dropped the OC down to 3.6Ghz, and it has been fine since. 3 hours of Kombustor, 50 passes of IBT, couple hours in Crysis, couple hours in Arma 2, TDU2. General usage, not a problem. Temps mid 30s idle, 67C max after 50 passes of IBT.

I just don't get it. Regardless of whether Vcore is 1.2 ...upto 1.28v , anything over 3.6Ghz and it falls over. Been hoping to make use of the 23x multi.

Although my ram was operating within the specs, under 1600mhz, voltages were SPD/XMP values suggested by Corsair also, it wouldn't stay stable.

My instinct is telling me it's the ram not wanting to play with the OC of the CPU. Is that possible?

Or am I just unlucky and have an i7 that is just one of the unlucky bunch?
 
Mine needed more juice than that once I hit 3.6GHz and above. I settled on 4.2GHz using 1.4vcore. 1.35v was enough for 3.6GHz. (May have been less but I was fine with 1.35v and had lost the patience to dial it right in.)

Also, did you go from a single GPU to those duals? You may wish to bump the PCI-E IOH voltage with dual GPUs. Especially higher end ones like yours. I ask because I noticed some issues with my GPUs crashing the whole system but thinking it was CPU at first. (It either straight BSOD'd or locked up needing a hard reboot.) I bumped up that voltage and so far, it seems to be ok. Though this was just done a couple days ago so I haven't had a whole lot of time to test it. The 2 games I have played most that do it were Rift beta and TF2. TF2 did the "multi-colour horizontal lines freeze" deal ATI cards seem to do. Rift just froze with the last scene or BSOD'd. (P.S. Note: Rift is still beta! So take that with a grain of salt so to speak.)

*bell rings*

Oh, what did you do for QPI voltage? It is very important for a higher OC. Mine is currently at 1.5v to maintain 4.2GHz.
 
Not had any crashing, freezing etc so far with the 3.6Ghz. Games have been great, no artifacting and stuff.

I think my QPI is at 1.35v , I "think" anyways. Will need to check that again. I was under the impression that was something you didn't want to tip over the 1.35v?
 
Arthur Hucksake said:
Not had any crashing, freezing etc so far with the 3.6Ghz. Games have been great, no artifacting and stuff.

I think my QPI is at 1.35v , I "think" anyways. Will need to check that again. I was under the impression that was something you didn't want to tip over the 1.35v?
Click to expand...

Lower is always better but here's how I justify my 1.5v QPI. My mob has OC Genie, an auto OC button I can push pre-boot and it will OC itself. It settled on 3.6GHz and set QPI to 1.587v. I figure 1.500v is good for 4.2GHz in comparison.

Now you have me thinking I should go try 1.45v and see how that goes.

P.S.

Well, I jumped straight to 1.35v instead and I am on test 7 of the 10K tests in P95 64. It passed 18 tests of 8K already. Solid so far.

I'm what I consider a "sloppy OCer". My patience wares thin, so I may stop before dialing in the best options. Especially when an OC fubars Widows, needing a reinstall. It happened 2 days in a row with a BSOD while testing. (I have a good image to go back to now though.) I'm hoping this is the case here and 1.35v sticks.

P.P.S

Well, 1 hour in with P95 and still rock solid. :)
 
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Got a random Video_TDR Bsod setting up 3D Vision. Couple of them in succession. Gutted!

Whipped the ram out and replaced it with Patriot Viper, only thing I haven't changed except the CPU.
 
Little, do you have LLC on?
At 1.30Vcore I'm hitting 84C in IBT and LinX at 4.0Ghz 23x 174 and ram at 1740.

I've been told keep the qtt/vtt at 1.4 if possible. My NB is at 55C so I have a bit of room to increase.

What are your settings for 4.2?

Aurther...... You should bump up your IOH Core to about 1.2V for your 2 cards.
 
Patonb said:
Little, do you have LLC on?

At 1.30Vcore I'm hitting 84C in IBT and LinX at 4.0Ghz 23x 174 and ram at 1740.

I've been told keep the qtt/vtt at 1.4 if possible. My NB is at 55C so I have a bit of room to increase.

What are your settings for 4.2?
Click to expand...

Mine has Low/High options rather than On/Off. I set CPU to low with 1.35vcore. If I left it on high it would drop to 1.288v and crash on full load. On low it bounces between 1.344v and 1.352v. I've been running small FFTs in P95 for over an hour now without issue. Room temp is 15C and the hottest core is pretty much solid at 66C. 67C for quick flashes from time to time.

I found using a lower multi seemed more stable for me. (200x21 vs 185x23. for 4.2GHz.) Though it's quite likely it could have been a different issue. I just like running my RAM at stock speed/timings to and 200x21 achieves that with a 4x multi.

Mine was 1.5v but since dropped to 1.35v.

Disabled Turbo Boost and Hyper-Threading.
BCLK 200x21 multi.
Vcore 1.35v
Low CPU Vdroop
CPU PLL auto
QPI 1.35v
High QPI Vdroop
DRAM multi 4x
IOH I added +0.1 (One is 1.6v from 1.5v the other 1.2 from 1.1v but I forget which is which ATM.)
ICH I added +0.1 (One is 1.6v from 1.5v the other 1.2 from 1.1v but I forget which is which ATM.)
 
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If you are using SLi you should try increasing your PCIE voltage, IOH Core and ICH Core a notch.

Ex.
PCIe: 1.56v
IOH-Core: 1.18v
ICH-Core: 1.15-1.2v ( this is very important when using multiple GPU's )

Try and check how it goes. SLI stresses your system and needs more power, since you have 2 x16 lanes being powered instead of a single gpu ;)
 
Little_4nic8er said:
Mine has Low/High options rather than On/Off. I set CPU to low with 1.35vcore. If I left it on high it would drop to 1.288v and crash on full load. On low it bounces between 1.344v and 1.352v. I've been running small FFTs in P95 for over an hour now without issue. Room temp is 15C and the hottest core is pretty much solid at 66C. 67C for quick flashes from time to time.
Click to expand...

Ah youre 10C below my room temp.
 
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