Haswell Overclocking Guides / Results

[Acebmxer]

Re: Haswell Overclocking Guides / Results

Update: I tried LinX with Linpack 11.0.5.009 in a Win7-64 non-OC'd environment. It put out one rep with 161.4 GFlops, then stopped on error in the second rep. Temps were reasonable -- 67c on hottest core. Now I have to go back to linpack 10.3 and see if it will work.

Yeah that what it would do for me and is doing the same in win8.

[ehume]

Re: Haswell Overclocking Guides / Results

Another update.

In the same non-OC Win7-64 environment I ran LinX with Linpack 10.3 -- includes AVX. LinX went quickly. For one thing, it went fast -- 6.9 seconds per rep instead of 257 seconds with non-AVX Linpack when the rig was OC'd to 4.7 GHz. And the speed of completions bears no relation to the difference in Gigaflops -- 101 GFlops with AVX, 66 GFlops on non-AVX.

CPU temps got up to 69c, hottest core.

So now I have decisions to make. Creep up the OC until I can run AVX Linx with no core going over 95c? Or just OC to 4.7 and expect I'll never need the max from the rig? I suppose I should try to see what the max temps are at the lower OC's, then decide.

Hi ho, hi ho, it's off to work I go. The maddening thing is that I have to come upstairs to get most big files and to interact with forums. The wireless in the basement is just so slow.

[ehume]

Re: Haswell Overclocking Guides / Results

Thanks to the rapid turnover of LinX+AVX reps (under 5 seconds), I was able to determine that an OC of 4.2GHz with a Vcore of normal+0.12v got me a max core temp of 94c. I also learned that setting LLC's to Extreme caused boot failures. Turning them off allowed for booting. Weird.

[Acebmxer]

Re: Haswell Overclocking Guides / Results

I would suggest trying fixed voltage. will all power saving enabled vcore will drop at idle. Also when using offset voltage linx with avx will up the voltage beyond what you will need.

For my cpu at 4.7ghz I need 1.330 set in bios but if I try to get offset to equal 1.330 I end up around 1.4xx at full load.

[ehume]

Re: Haswell Overclocking Guides / Results

I would suggest trying fixed voltage. will all power saving enabled vcore will drop at idle. Also when using offset voltage linx with avx will up the voltage beyond what you will need.

For my cpu at 4.7ghz I need 1.330 set in bios but if I try to get offset to equal 1.330 I end up around 1.4xx at full load.

Yes. And if all I was going for was trophy runs I'd do exactly as you say. But I am casting about for a daily overclock. For that, I'd like to leave my chip unmolested by higher Voltages until they are really needed.

I'm leaning toward 4.5 as a compromise between the max my chip can handle and stay under throttle temps (4.2), and its max stable OC (4.7).

[boondocks]

Re: Haswell Overclocking Guides / Results

As long as the power saving options are enabled, Haswell will drop the voltage and the clock at idle.....so what Ace is telling you is that setting the vcore with no offset is not going to subject the cpu to high voltage all the time.
With Haswell it's perfectly alright to set vcore straight out. Use cpuz or HWINFO to monitor and you will see that's so......Aida works too but the vcore reading was off last time I checked alongside cpuz & my DMM.

[ehume]

Re: Haswell Overclocking Guides / Results

Ah. Thanks for that. Makes sense. This adaptive Voltage: with CPU clock set to 4.5, and Vcore normal + 0.1v, it actually passed LinX+AVG, but Voltage maxed out at 1.324v. On plain LinX it maxed out at 1.21V, more or less as expected.

So now I can just go back to fixed Voltages. Or leave it as normal + 0.x, so that it only goes really high when the cpu maxes out.

I'll have to try it both ways. I can foresee a long set of test runs before I settle on a final setting. This means I have more excuses to play.

[Acebmxer]

Re: Haswell Overclocking Guides / Results

If the cpu is fully stable when you set 1.21v manually but is at 1.324 when using offset, why would you go with the higher voltage setting?

[wazza300]

Re: Haswell Overclocking Guides / Results

doesn't setting a lower llc lower load voltage? it should do

that's with offset

[Acebmxer]

Re: Haswell Overclocking Guides / Results

With Haswell, Intel built in over volting when AVX instruction set is being used. So you can dial in offset voltage using a stress test that does not use AVX. Once you use AVX the cpu will over volt over what you set with offset and do what it wants to do.

The only way around this is to enable all power states so vcore and cpu speed drop a idle and use fixed vcore. This way cpu will not over volt while using AVX instruction set.

[1000moths]

Re: Haswell Overclocking Guides / Results

I don't see that voltage drop, if I set a manual volt it stays static, even with all power saving set in the BIOS, the multiplier and frequency drop by the Core,VID, and VRM all stay at the value i've set in the BIOS.

[Acebmxer]

Re: Haswell Overclocking Guides / Results

What are you using to monitor vcore? I had to use Cpuz 1.64.0 to see idle voltage 1.64.3 would not. Or get a DMM and you will see voltage drop. I also put a video on first post show it both with DMM and cpuz.

[1000moths]

Re: Haswell Overclocking Guides / Results

AIDA (latest beta), CPU-Z 1.64 (OC) all show a static 1.20 when manually set to that in BIOS. I don't have a MM anymore unfortunately or i'd check with that.

I've set all the power saving options to ENABLED, and when using an offset all of the voltages drop, and I get around 9w draw when completely idle, but with the manual voltage lowest I get is 15w draw.

[Acebmxer]

Re: Haswell Overclocking Guides / Results

AIDA (latest beta), CPU-Z 1.64 (OC) all show a static 1.20 when manually set to that in BIOS. I don't have a MM anymore unfortunately or i'd check with that.

I've set all the power saving options to ENABLED, and when using an offset all of the voltages drop, and I get around 9w draw when completely idle, but with the manual voltage lowest I get is 15w draw.

See below try opeing more the one window of cpuz

Yeah for some reason 1.64.3 would not show idle voltage, always fixed vcore. 1.64.0 with OC skin show me idle voltage. Some times you may have to reopen it, max 3 times (so far for me) for it to show idle voltage. Most of the time you need to leave it open for 20 sec or so before it will show idle voltage.

Video of DMM vs CPU-z voltage. LLC was set to extreme.

Also try setting turbo to auto and all other cstates and eist to enabled.

[1000moths]

Re: Haswell Overclocking Guides / Results

Tried all of those, in offset CPU-Z shows the drop immediately, with set limit it sticks at the limit.

Guess i really need a DMM to check it.

I'm running F6J BIOS too.