Core i7/X58 Overclocking Thread

[Classic Satch]

I guess everyone has their own priorities. HT serves absolutely no purpose for me so it stays off. I'm spending every moment of free time playing Fallout 3 and it's DEFINITELY not necessary for that.

[anzial]

Pisklink, nice results. What's your cpu batch #?

[SteveRo]

Today I started OC'ing my new hardware. Besides the first results (which look promising, I gues) I also bumped into some questions.

Questions:
As you can see I'm using Asus P6T mobo but there are some settings in bios which I'm not sure of what to select. These are the following items and settings I applied:

C1E Support: disabled
Hardware prefetcher: disabled
Adjecent cache line prefetch: disabled
Intel Virtualization tech: disabled
CPU TM function: enabled
Execute-disable bit: enabled
Intel HT technology: disabled
Active processor cores: all
A20M: disabled
Intel speedstep tech: disabled
Intel turbomode tech: disabled
Intel C-state tech: disabled

- Did I apply the correct settings on overall?
- Is it possible to enable a power consumption saving setting (like speedstep for instance) while overclocking?
- Is it possible to use turbomode on P6T when using 190+ bclk?

First results
After a lot of reading I applied some reference voltages in the bios and started OC'ing right away. It seems to be stable right away. I'm not used to that after switching from P5E3-Premium to this board. These results are without HT enabled. But is there much more vcore necessary when enabling HT? I think my temps are good and still have some potential left. Nonetheless I would like to know your opinion on these results and if possible give some advice for improvement.

Settings:
MP: 20x
BCLK: 200
DRAM: 1200
Uncore: 3200
QPI: 3600
Vcore: 1.35
CPU PLL: 1.92
QPI/DRAM: 1.35
CPU spread spectrum: disabled
PCIE spread spectrum: disabled

Everything else on AUTO

a couple ideas for you.
i think the max cpu pll should be no greater than 1.89 (according to intel)
you may need more than 1.35 vcore for 4 ghz, I needed 1.4v

[Pisklink]

Pisklink, nice results. What's your cpu batch #?

Batchnumber is 3836A875

a couple ideas for you.
i think the max cpu pll should be no greater than 1.89 (according to intel)
you may need more than 1.35 vcore for 4 ghz, I needed 1.4v

Thanks for the overview of voltages. It seems I don't need more Vcore with current settings because if you look at the screenshot I already was benching on 4Ghz @ 1.35v. Only if I would put on HT I think I will need more voltage. I will try to put CPU PLL lower and see if it's still stable.

[Pisklink]

Why is it so quiet in here?

Is the max. voltage for the CPU 1.55v according to Intel specs in the overview above?

[Khalmyr]

I still don't get what PLL is for.

I was priming @ 4Ghz, 1.35 vQPI and 1.88 PLL which are the maximum safe values set by Intel.
Then i decided to put PLL back at 1.80 and it kept priming for 6 hours until I had to stop.

weird

[Chicken Patty]

I keep seeing how some of you have better stability when raising CPU vtt compared to core voltage.

Well raised CPU VTT from 1.25v to 1.30v and at same vcore went from no stability at all @ 4.1 Ghz, to at least running 3dmark, Will test stability further over the next few days, see how it behaves

[GenTarkin]

I finally got ahold of a kill a watt and measured my OC power numbers =)
Very interesting to say...and system not using anywhere near what I thought it would.
My major hardware is listed in my signature.
Here are my readings 3822mhz @ 1.27v 182x21 VTT/QPI@ 1.25v 3095mhz .. all other voltages on auto:
Computer off but plugged into wall: 2watts
POST to windows an average of 160-190watts
Windows idle:160-175watts
WCG number crunching: 290-300watts
WCG+3dmark06: 370-395watts
3dmark06 only: 260-290watts
Prime95 blend: 307watts
CoreDamage: 325watts

Now the next point is...the PSU effeciency is rated @ 80+. I am not even using its full load capacity meaning its more likely less effecient then that. So, assuming 75% effeciency...is it correct to take 25% off the above numbers and that number is the true power draw of my PC? (obviously I know the socket sees the full numbers listed above, but Im talkin internal usage after the effeciency of the PSU is taken into affect...)

[poupouxios]

Hey huys! I tried to overclocked my core i7-920 and the only stable until now is 21x166 in 1.128V! I run LinX and it passed and the max temps are 65-75. I ordered a few days ago 4x1 OCZ GOLD edition pc3-14400 1800mhz and i will try to overclock when they arrive. My problem is if i use 3x1gb of OCZ is it going to work trible channel?

[Pisklink]

Now the next point is...the PSU effeciency is rated @ 80+. I am not even using its full load capacity meaning its more likely less effecient then that. So, assuming 75% effeciency...is it correct to take 25% off the above numbers and that number is the true power draw of my PC? (obviously I know the socket sees the full numbers listed above, but Im talkin internal usage after the effeciency of the PSU is taken into affect...)

I'm not sure but I always thought the efficiency raises when not using the full potential of a PSU. So if a PSU is rated for 800W it will provide e.g. 85% efficiency at that max capacity. If less power is drawn the efficiency will raise because all the PSU components are less stressed.

@ All

Is it correct that 1.55v is the max. allowed vCore according to Intel specs?

[anzial]

I don't get it, what's the speed on my computer? I guess, at stock speed, and idle cpu one core is overclocked, and the rest are taking a break? So tweaker reports the multi of the cores that are on the break, and CPU-Z- the single working core. Is that a reasonable assumption?

[Splave]

I'm not sure but I always thought the efficiency raises when not using the full potential of a PSU. So if a PSU is rated for 800W it will provide e.g. 85% efficiency at that max capacity. If less power is drawn the efficiency will raise because all the PSU components are less stressed.

@ All

Is it correct that 1.55v is the max. allowed vCore according to Intel specs?

Absolute max is 1.55v, Your problem would be cooling that damn thing at that voltage. Do you have a un-heated basement?

[Pisklink]

Thanks for your reply. Luckily I'm living in an iglo on the Antartic so cooling shouldn't be a problem.

Nah, my chip doesn't get that hot really. It's watercooled by a D-Tek Fuzion version 1 with 5,5mm nozzle and at 4080Mhz it gets around 48 - 50 degrees celcius in Realtemp.

[SteveRo]

Hey huys! I tried to overclocked my core i7-920 and the only stable until now is 21x166 in 1.128V! I run LinX and it passed and the max temps are 65-75. I ordered a few days ago 4x1 OCZ GOLD edition pc3-14400 1800mhz and i will try to overclock when they arrive. My problem is if i use 3x1gb of OCZ is it going to work trible channel?

If you can stay under the max volts (I would want to stays under 1.35 qpi vtt and under 1.65 for the memory) you should have no problem running that memory 3x1gb - running 3 not 4 strips correct?

[SteveRo]

I don't get it, what's the speed on my computer? I guess, at stock speed, and idle cpu one core is overclocked, and the rest are taking a break? So tweaker reports the multi of the cores that are on the break, and CPU-Z- the single working core. Is that a reasonable assumption?

If you have C1E, eist or some of the other power saving stuff turned on in the bios - that seems to confuse some of the apps. the latest version of realtemp shows the multi dropping down if C1 is enabled - I can confirm that.

[anzial]

I wan't talking about realtemp, it's the discrepancy b/n the tweaker and cpu-z I was talking about.

[SteveRo]

I wan't talking about realtemp, it's the discrepancy b/n the tweaker and cpu-z I was talking about.

when I have C1E enabled cpu z reports just a little under the bios clock.
I don't know what the problem is with tweaker.

[poupouxios]

If you can stay under the max volts (I would want to stays under 1.35 qpi vtt and under 1.65 for the memory) you should have no problem running that memory 3x1gb - running 3 not 4 strips correct?

Thanks for yous answer! Yes i will use 3 strips! But the max volts of OCZ 1800mhz are 1.9volts. You mean to stay under this max volt or the 1.65 max volt?

[Khalmyr]

1.65v as stated by Intel

[SteveRo]

Thanks for yous answer! Yes i will use 3 strips! But the max volts of OCZ 1800mhz are 1.9volts. You mean to stay under this max volt or the 1.65 max volt?

Well, the jury is still out on this, intel says - some where (I do not know where) not to exceed 1.65v but then there's the intel electrical spec - see below - not sure what to believe. I try to stay below 1.65, a lot of folks are going by the rule of keeping memory volts within 0.5v of qpi/vtt. So if your qpi/vtt is 1.35v, you want to keep your memory volts to leas than or equal to 1.85v. I know of no one that had fried their cpu (yet).

[unclewebb]

anzial: RealTemp reports your average CPU multiplier. Depending on your C1E / EIST bios settings and how the Windows power options are set up (Minimum processor state), you might see the multi jumping up and down at idle. I left RealTemp like this because it best shows you what's going on. If EIST and your power options are set up properly, at idle, you should have a consistent multi of 12.0 on Core i7. If you don't want your multi dropping at idle then you need to make sure SpeedStep is off and Minimum processor state is set to 100%.

Sometimes CPU-Z does some averaging and reports the multiplier at its full value but the displayed MHz will be based on some sort of average. Your screen shot is a good example. CPU-Z shows 133.3 X 22.0 which doesn't equal 2907.9 MHz which is displayed.

rge did a lot of Core i7 testing for me so I think you should be able to trust RealTemp MHz as well as temperatures. Here's the most recent release:

http://www.xtremesystems.org/forums/...postcount=3166

RealTemp 2.70 does not properly support Core i7 so don't use that version.

[hlonipha]

what are the max temps for the 920? is 75c too hot on core 1-2 and 69 on 3-4 running 2 instances (8 threads) of p95? running 194x21 turbo on.

[Chicken Patty]

what are the max temps for the 920? is 75c too hot on core 1-2 and 69 on 3-4 running 2 instances (8 threads) of p95? running 194x21 turbo on.

absolute max is 100ºc

I like to be under 85ºc when I was on air.

[hlonipha]

ok cool im not so bad then.

[SteveRo]

anzial: RealTemp reports your average CPU multiplier. Depending on your C1E / EIST bios settings and how the Windows power options are set up (Minimum processor state), you might see the multi jumping up and down at idle. I left RealTemp like this because it best shows you what's going on. If EIST and your power options are set up properly, at idle, you should have a consistent multi of 12.0 on Core i7. If you don't want your multi dropping at idle then you need to make sure SpeedStep is off and Minimum processor state is set to 100%.

Sometimes CPU-Z does some averaging and reports the multiplier at its full value but the displayed MHz will be based on some sort of average. Your screen shot is a good example. CPU-Z shows 133.3 X 22.0 which doesn't equal 2907.9 MHz which is displayed.

rge did a lot of Core i7 testing for me so I think you should be able to trust RealTemp MHz as well as temperatures. Here's the most recent release:

http://www.xtremesystems.org/forums/...postcount=3166

RealTemp 2.70 does not properly support Core i7 so don't use that version.

thanks for a most excellent app!
getting better all the time!