i7 920 D0 @ 4GHz needs lower temps

[Tristor]

So, I'm working on a box currently based around an i7 920 D0 on an E760 Classified. I've lapped the CPU to 1200grit and it passed a flatness test. I used the dots and X method of applying the G751 thermal paste on top of the IHS and attached the Noctua UH12P SE2 (push/pull), which is currently unlapped but very flat from the factory.

Everything is in a Coolermaster Stacker 830 with 3xScythe S-Flex SFF21F on the side for intake, 2x SFF21F in the front for intake (one is ducted via custom plexi duct through the #2,#3, and #4 from the top 5 1/4 slots right into the CPU cooler over the RAM), 1x SFF21F in the top for exhaust, and 1x SFF21F in the rear for exhaust + the PSU fan. Additionally there is a 60mm fan on the NB heatsink blowing towards the top (NB is at 55-60C pretty constant) and over the heatpipes on the bottom of the CPU cooler. Room ambient temp is 67F.

I'm currently 1 hour stable Prime95, but after about 1 hour and 30 minutes, it BSODs usually with a 101 error code (indicating I need to increase CPU vCore). My issue is I have the voltage higher for stability than I'd like it to be and I'm being forced to push it further, which is causing my temps to go above my window. Peak load is 85C on Core 0, avg load is 83C. I'd like to see peak load of 80C and avg load of 75C+. I'm planning on lapping the cooler and reapplying the thermal paste tomorrow, but I'm looking for other ideas.

Any ideas would be helpful, as at this point I'm at a loss for what to do other than lapping the cooler and pressure modding it to try to drop the temps, but that's only going to gain me maybe 3C across the board. Any and all ideas welcome.


My current BIOS template follows:

Mother Board ( EVGA X58 Classified E760 )
Bios ( S61H )
CPU ( 920 D0 )
CPU Cooler ( Noctua NHU12P SE2 Push/Pull )
Memory ( Corsair Dominator GT 1866 7 8 7 20 )
PSU ( Enermax Revolution85+ 1050W April 2009 Rev2 )
GPU ( EVGA GTX275 Superclock 1.75GB X 2 )
Drivers ( 191.07 )
Operating System ( Windows 7 64bit Ultimate )


Frequency Control
CPU Clock Ratio ( 20X )
CPU Host Frequency (Mhz) ( 200 )
MCH Strap ( Auto )
CPU Uncore Frequency (Mhz) ( 3205hz { 16X } )
CPU Clock Skew ( 0 ps )
Spread Spectrum ( Disabled )
PCIE Frequency (Mhz) ( 101 )


Memory Feature
Memory Speed ( XMP Profile 1 )
Memory Control Setting ( Enabled )
Memory Frequency ( 1600Mhz / 2:8 )
Channel Interleave Setting ( 6 Way )
Rank Interleave Setting ( 4 Way )
Memory Low Gap ( Auto )
tCL Setting ( 7 )
tRCD Setting ( 8 )
tRP Setting ( 7 )
tRAS Setting ( 20 )
tRFC Setting ( 57 )
Command Rate ( 1t )


Voltage Control
EVGA VDroop Control ( Without VDroop )
CPU VCore ( 1.2875v )
CPU VTT Voltage ( +275 )
CPU PLL VCore ( 1.800 )
IOH PLL VCore ( 1.350 )
DIMM Voltage ( 1.62 ) (1.65v in E-LEET, at 1.65v BIOS is reads 1.69v)
DIMM DQ Vref ( +0mV )
QPI PLL VCore ( 1.375 )
IOH VCore ( 1.375 )
IOH/ICH I/O Voltage ( 1.550 )
VTT PWM Frequency ( 250 KHZ )
CPU PWM Frequency ( 940 KHZ )
CPU Impedance ( Auto )
QPI Signal Compensation ( Auto )
ICH VCore ( 1.150 )


CPU Feature
Intel SpeedStep ( Disabled )
Turbo Mode Function ( Disabled )
CxE Function ( Disabled )
Execute Disable Bit ( Disabled )
Virtualization Technology ( Disabled )
Intel HT Technology ( Enabled )
Active Processor Cores ( All )
QPI Control Settings ( Enabled )
QPI Link Fast Mode ( Enabled )
QPI Frequency Selection ( 4.800 GT/s )
OC Recorvery ( Enabled )

PnP/PCI PCI Express
Maximum Payload Size ( 4096 )

 

[2March]

I don't know how much experience you have with overclocking so don't be offended.

Usually every proc has a speed at which the needed Vcore for a speed increase ramps up aggressively. Usually that's the speed where I quit. You may want to try how much Vcore it needs for higher speeds to get an idea how sensitive it is. You may be in that zone right now. I always hate to say it but D0 doesn't automaticly means you get a good OC but you already knew that I guess

My C0 does 3.8 stable at 1.248V Vcore, HT on. Temps reach about 75 degrees.

I would say considering your Vcore, cooler and speed those temps are on the high side but as said before, there is no such thing as a garantied OC.

 

[MrK6]

First thing I'd try is turning on VDroop control - that alone can stabilize an overclock. You should still try to get your temps down though. Enabling VDroop might allow you to drop the voltage some, but might not have an effect on temps (voltage under load could still be similar, for example). Since you want to stay at 4GHz, the only other place to look would be to improve your cooling. The Prolimatech Megahalems is evidently the current king of cooling, but the Noctua UH12P is also a pretty damn good heatsink, so I don't think you'd see much improvement switching (maybe a few degrees C). If you are going to lap your Noctua heatsink, limit yourself to 600 grit, anything after that is overkill and sometimes even hurts performance. I'd also recommend grabbing a 120x38mm fan (or two) for the heatsink. While the Noctua fans are quiet, they don't have the pressure needed to push a lot of air through the fins of the heatsink. A bigger (wider) fan generates this pressure and does drop temps noticeably. Finally, judging by your description of your case, it sounds like you have way too much intake (5 fans) compared to your exhaust (2 fans + PSU). First, try running your case without any of the three side fans running to generate negative pressure in the case. Also, try turning on only one fan on the case's door (no more). I'd imagine either of those scenarios will generate better temps for you. Good luck!

 

[Tristor]

I'll try out turning Vdroop on, but I'm afraid there will be significant voltage spikes during the transition period between idle and loaded states. I usually OC with Vdroop off for this reason.

I'm not sure that I have an airflow problem in the case. I intentionally have a positive pressure airflow design to cut back on dust generation. I'll see about throwing a couple of Scythe SFF21Fs on the CPU cooler as well, maybe Gs. I can't go to anything too loud though as I have a noise ceiling I can't exceed as well.

 

[MrK6]

I'll try out turning Vdroop on, but I'm afraid there will be significant voltage spikes during the transition period between idle and loaded states. I usually OC with Vdroop off for this reason.

Ah, well, I forgot to mention such a caveat: different motherboards (and even BIOS revision of a motherboard) handle Vdroop differently, so yes, use what works best for you.

I'm not sure that I have an airflow problem in the case. I intentionally have a positive pressure airflow design to cut back on dust generation. I'll see about throwing a couple of Scythe SFF21Fs on the CPU cooler as well, maybe Gs. I can't go to anything too loud though as I have a noise ceiling I can't exceed as well.

Unless you have fan filters on those 5 intake fans, I don't think positive pressure really doesn't keep dust down. The problem with positive pressure is it can trap heat pockets within the case, which will increase temperatures significantly depending on case design. Removing those 3 side intake fans will more than make up in noise for any fan changes on your heatsink. That's another benefit of a 120x38mm fan on the heatsink - you can run it at lower RPMs and generate the same or higher airflow with greater pressure.

 

[Ayah]

Try turning on Turbo for a 21X multiplier and using a 190 FSB.
I find that my processor runs alot cooler with a 21X multiplier than a 20X multiplier at the same effective speed(190 vs. 200 FSB)

 

[Tristor]

Yep, all the intakes are filtered. That's one nice thing about the Stacker 830 vs other cases is that everything is filtered out of the box. At any rate, we may attempt to put a 120x38 fan in place, but I'm not sure if that will fit, we've got little space to work with.

Turbo mode might potentially be an option if nothing else presents itself, but I'd prefer 4GHz on all cores instead of only on Core 0 (turbo mode only changes multiplier for one core).

I am going to lap the cooler tonight and see if I can figure out a way to pressure mod it, although it has a different bracket style than most other towers do so a simple washer won't do it.

 

[postaled]

I'd try to do everything you can to lower your vcore, I was runing ~ 10C higher with the normal vcore @ 3.8ghz with my d0 and I have had no issues with stability in p95/linx after dropping mine down to 1.15 with vdroop off. With air cooling with that I idle ~ 38 and don't break 65C after hours of full load, also my room stays ~75F. Not sure if you'll be able to but just try to get that vcore lower imo, maybe I'm wrong though :\

Good luck on getting your temps down.

 

[GLeeM]

Have you checked your temps with the side of the case off? How much better are they?

I agree with trying the 21 multi - on my ASUS P6T Deluxe V2, all cores are at 21 not just one. Have you tried 21?

I have 920 D0 HT on, 21x190 with 1.264V (from CPU-Z), lapped (didn't help much) TRUE (one original fan) with washer, load is upper 70s with side of crappy case off.
If I go higher, temps are worse and it needs alot more V, I should really do 3.8 or 3.9 and be happy with much lower V and cooler temps.

 

[Tristor]

I'm sitting at 1.250v @ 3.9GHz (20x195) after reseating the cooler and increasing the pressure, it looks like load peaks are around 75C, which is much more manageable. I'm just not seeing anything stable at 4 (20x200) without upping voltage significantly, so either I've hit the wall or I'm doing something wrong.

I'll try enabling Turbo Mode next.

 

[rgallant]

you have the CPU VTT @ +275 , the 760 default in the bios is 1.2mv not 1.1 ,so 1.2 + .275
= 1.475 mv ,well over the intel 1.35mv MAX
-so I would just go with the +75\+100 mv
-try the 21 multi.x 191
-do not use the memory XMP profile for now ,could be why you need a high vtt ,try apox.8,8,8,24,88 for testing.
-use 1.4 vcore then dial it down. if that's possible , but it looks like you put a lot of time into the settings you have.
-nb temps = a fan is needed ,mine is 50c in the bios ,no way to check in windows under load.
-I use a modded spot fan between the vid .card and the nb heat sink blowing out[pci FX] so the slot is not needed for now ,
-my vreg has a 92mm mounted blowing down on it, 45c is max. but I'm on cpu water so I have the room.[haf 932 dust magnet]
-I haven't tweek my 760 yet , just running @ 4.0 @3.125 vcore [bios no vdroop]

- so maybe try that to see if the high vtt is the temp issue.
-also run some games and log the temps. mine only runs COD6 MW2 @ 14% cpu load LOL

 

[Tristor]

So 3.8 with Turbo on at 1.268v = no BSOD, but it locks up at 7 minutes and 32 seconds into Prime95. I'm going up to 1.275.

I can lower VTT, but I don't know that it will make any significant differences.

The NB temps are fine, 53-65C with little variance at load. There's a 60mm fan on the NB cooler, which is a pretty well made heatpipe cooler on the E760. BTW, you can see NB temps in Speedfan (get 4.40 Beta 5 for i7 accurate temps).

I need 24 hour Prime95 stable, I'm not worried about game stability, I'm sure it's stable in games but I need to be 100% sure it's rock solid.

 

[Ayah]

You might want to try LinX or Intel Burn Test. (Same program at the base, just different interface)

If your system is unstable, it should quick relatively fast with a high memory usage (4GB+)

 

[Tristor]

I've got it stable with turbo mode on at 3.8 (190x20/21) with load peaks of 77C and load avgs of 74C. It seems this is the best I can do, thoughts?

 

[BTRY B 529th FA BN]

Wait a minute woo woo woo, hold the phone, you have an Enermax 1050 Revo running with that mobo? I thought they were ... whats the S/N on the PSU?? i've been holding off on building mine (sig rig3) because the S/N on the Enermax Revo and Evo needs to be above 95xxxxxxx to be the correct revision to work with the 760. Which is your S/N?

 

[Tristor]

Wait a minute woo woo woo, hold the phone, you have an Enermax 1050 Revo running with that mobo? I thought they were ... whats the S/N on the PSU?? i've been holding off on building mine (sig rig3) because the S/N on the Enermax Revo and Evo needs to be above 95xxxxxxx to be the correct revision to work with the 760. Which is your S/N?

I don't know off hand. The original PSU Newegg shipped was manufacturered in December 2008 and was the wrong revision, I RMAed it and received a replacement from Enermax that was manufactured in April 2009. It seems that the 2nd revision started being manufactured in March 2009.

You can just look at the box and see the month/year of manufacturer. The version on both revisions says "1.0".

 

[coreyb]

god it sounds complicated to overclock these new chips.

 

[Tristor]

god it sounds complicated to overclock these new chips.

Yes.

 

[BTRY B 529th FA BN]

I don't know off hand. The original PSU Newegg shipped was manufacturered in December 2008 and was the wrong revision, I RMAed it and received a replacement from Enermax that was manufactured in April 2009. It seems that the 2nd revision started being manufactured in March 2009.

You can just look at the box and see the month/year of manufacturer. The version on both revisions says "1.0".

Your PSU box should have it, look at it and let me know, if you can, but thanks either way

 

[Tristor]

Your PSU box should have it, look at it and let me know, if you can, but thanks either way

I cut off the S/N on the box for the mail in rebate so it's not on there anymore. Whoops. I probably should have written it down first.

 

[Thor86]

Disable HyperThreading in your mobo bios settings, if you don't need it.

 

[Tristor]

Disabling hyperthreading isn't an option, that's one of the primary reasons I got the i7 and not the i5.

 

[Thor86]

Disabling hyperthreading isn't an option, that's one of the primary reasons I got the i7 and not the i5.

Why would that not be an option? Are you planning on cpu intensive tasks such as media encoding or vms?

If not, then HT is useless to you, and holding you back from your max GHz oc because of high temperatures it causes.

Google overclock D0 temperatures. This is well known D0s run hotter that previous versions of the i7.

 

[postaled]

That is still pretty high for only @ 3.8 on your temps though... :\ I wish I knew something to help you out. And yeah only enable HT if you need it. I have it on for media encoding myself.

 

[imaxcpu]

Hi, Just a thought on your great effort with regard to Therm-paste, sounds like you might be over doing it, just a thin, thin film is need and is best esp if you are flat. It >will make a difference.

Take care.