New member...OC'ing an older combo (P8Z68-V and i5-2500k)

[texasniteowl]

I've had this combo for a couple years and to be honest, it is still overkill for the majority of my uses. However a few weeks ago my Corsair H60 stopped cooling, so I replaced my cooling, and since I'm "playing around" with my system at the moment I decided to go ahead and try to OC it.

Basics: i5-2500k, ASUS P8Z68-V (bios 3402), 8gb Corsair ram, Thermalright True Spirit 140 BW Rev. A cpu cooler, 4 GT AP-53 case fans, Plextor M5 ssd, WD black 1tb, no gpu...using integrated (don't shun me!). Corsair HX-520 PSU (I think) that is about 6 yrs old I think.

Right now, I have set my turbo multipler to 44, LLC is regular, VRM is manual/350, optimized phase control, t.probe duty control, 110% cpu current capability, offset + 0.005, cpu spread spectrum disabled. I understand with such a low OC, I can set VRM back to Auto?

My idle vcore with these settings is 0.992-1.000 (cpu_z) and my highest load vcore is 1.320-1.328 (light load, during the image editing/GIMP) with sustained 100% load at 1.280-1.288. I did run 1 cycle of the RealBench benchmark tests and watched cpu_z while that was running to note those vcores. Max temps reached during the 1 run of RealBench were: 60/56/61/62. Note...at these temps, my fans only run at about 70%, not full speed.

I suppose I'm looking for input on how those voltages seem. I don't really have much interest right now in pushing the OC higher. I was getting input on another site, but their focus tends to be solely on the 100% load (ie. prime95) vcore which runs lower than the light load (ie. GIMP image editing) part of the RealBench tests. So is a light load vcore of 1.320-1.328 normal when the 100% load vcore is 1.280-1.288? On my system I am much more likely to be constantly jumping between the 1.320 and idle 1.000 than I am to be at 100% load. After all, it jumps to the 1.320 just opening a new tab in Chrome.

I have saved some screenshots of my bios, so if need be I will figure out how to post them here.

Thanks for any comments.

[texasniteowl]

Yeah, so far I see no reason to move off Win 7. I'll be keeping an eye on W10, but not impressed by the inability to control windows updates. Curious to see what else comes out when it gets released. Anyway, I've only had one BSOD since I started attempting to OC...and I think that was before I even posted here...in fact, I think that happened one of the handful of times I tried a manual voltage before switching to offset. Since then I have 15 pages of tests with no BSOD. (I made up a form for myself with all the BIOS settings. So the ones that don't change once set are entered and then I write in the ones I change.)

I guess I will just use the system for a day or two and see how things go. The drop when realbench stopped is where I saw my lowest idle vcore of 0.968 and then it rebounded back to 0.976. Still, overall, it seems like 44 (or maybe even 45) at load of 1.264-1.272 is good enough.

And thanks so much for your feedback!

[Arne_Saknussemm]

Nah you're welcome 😮

Sounds like a good way to keep track of things...nice and methodical...good results!

Probably good to run the system a couple of days...best stability testing is using the rig for your normal stuff as well as stress tests...

[texasniteowl]

Everything continued fine yesterday. Left the machine at times...a couple times for several hours. Had no issues or hangs so far. This morning I have bumped it up to 45. Had largely the same results as on 44. Only exception is that during GIMP it did go to 1.320 more often than 44 did (44 stayed mostly at 1.312). Otherwise, only other change were slightly higher temps of 61/58/63/63 (44 was 58/55/61/61) ... but ambient was 1 to 1.5 degrees higher as well.

We will see if I leave well enough alone this time or whether I can't resist and drop the offset to -0.015 just to see what happens.

[Arne_Saknussemm]

tick tock

hmm I wonder...

tick tock

maybe it'll be stable and temps will be lower

tick tock

no, leave it alone...things are fine as they are what more do you want

tick tock

but what if....?

😉

[texasniteowl]

Well after 2 days at the previous settings with absolutely no problems...I had to tinker a bit more. So I had been at Regular LLC with -0.010 offset and idle vcore of 0.976 - 0.984 and full load vcore of 1.264-1.272.

So first, just for the purposes of experimentation...I changed LLC to Medium and decreased (or increased the negative) offset to -0.015. Idle vcore ran 0.976 down to 0.968 but load vcores were higher than the previous setting with full load running 1.288 to 1.296. Definitely a step backwards in terms of load vcore.

Maybe it is just my board, but even at Medium LLC, load vcores remain much higher (have less vdroop?) than they need to be. If I am doing my math right, to get my load vcores down to the 1.264 range that works fine under Regular LLC I would have to increase my offset another -0.03 or at least -0.025 for a total negative offset of 0.040 or more, but...that would or should corresponding drop my idle vcore to 0.951 or lower. I mean...maybe I should try it? Maybe my chip will handle an idle vcore that low? I guess the only way to know is to try...

Anyway, next...I went back to Regular LLC and set offset to -0.015. Idle vcore runs 0.976 down to 0.968 while full load vcores run mostly 1.264 +/-. (Lowest spotted during load was 1.256.) "Light" load vcore (aka during GIMP part of benchmark) was roughly 1.304-1.312.

Note: For speed, my multiplier has mostly been 44. But in tests so far, I get essentially identical results for 44 and 45.

I guess, depending on how things run at this -0.015, I might get the itch to try going even lower. We will see. Since watching for idle instability means just using the system it will be at least a day or two probably before I try changing anything again. And I guess it looks like I will be staying on Regular LLC since Medium always raises the load voltages so much higher.

[Arne_Saknussemm]

Yeah regular is good...vdroop is good

Those volts coming down nicely step by step 🙂

[texasniteowl]

Well, I can't leave it alone now! 😮

Booting this morning, I changed to 45 AND dropped the offset again. Now -0.020 still on Regular LLC.

It did boot. And I ran 1 benchmark test cycle.

idle is running 0.968 with occasional drops to 0.960
GIMP ran mostly at 1.304
h264 ran at 1.256-1.264
OpenCL ran (mostly) at 1.272
multitask started at 1.272-1.264 and then dropped to 1.264-1.256
(with a couple drops as low as 1.248)

temps ran 60/57/63/62 at 24 ambient (ambient about a degree warmer than yesterday's test at 44)

So...we will see if idle drops down to 0.960 are too low or not!

[Arne_Saknussemm]

Holding up OK?

[texasniteowl]

Yes it is! I haven't run stress test against it. But I'm still at 45 with the -0.020 offset and regular LLC and I've had no issues during use so far. No idle hangs or lockups after exiting programs, etc. No problems during boot.

I am curious about dropping the offset to -.025...load might come down a little farther, but at some point I will start to have idle issues, right?

Honestly though, 100% load at 1.256-1.272 at 45 seems reasonable. Idle is staying at 0.968 with occasional drop to 0.960.

I suppose I could always drop the offset to -0.025 and increase the multi to 46 to balance them out! :cool: But, I think I am looking good where I am at.

[texasniteowl]

So, it has been running completely fine at 45 and -0.020. So of course I had to change things.

I am now at 46 and -0.025. Only been about 1 hour but so far so good. Did run 1 cycle of benchmark to see where things stood.

idle: 0.960-0.968 with occasional drops to 0.952 after heavy usage programs (ie. benchmark) quit
GIMP: 1.304 +/-
h264: 1.256 +/-
OpenCL: 1.264-1.272
multitask: 1.264-1.256-1.248

temps: 60/57/63/62

So I will run this for a few days and see if I have any idle instabilities or not!