i5 at 4.0GHz 24/7?

Hey guys,

As the title says, what do people think about running a i5-750 running at 4.0GHz 24/7? Details as follows:

Multiplier and BLK at 20*200
Voltages:
CPU: 1.37500V
QPI/Vtt: 1.210V
PCH Core: 1.120V
CPU PLL: Auto (ie not sure)

The RAM is at 1600MHz and 1.65V, but they are rated at said speeds so I'm not too worried about them.

With Prime 95 the temps are:
Core 0: 73
Core 1: 76
Core 2: 66
Core 3: 78

And with IntelBurnTest:
Core 0: 82
Core 1: 86
Core 2: 72
Core 3: 86

(celsius by the way, lol)

What do people think? Thanks in advance

 

Looks like you managed a good overclock with that proc.. All I can say is congrats!! If you are worried use the default clocks but looking good to me. cheers! -Beaux

 

All I can say is the thermalright MUX works wonders, lol. I'm actually stil running Prime 95 at the moment, but I've got high hopes since I've been running IntelBurnTest like crazy. Results tomorrow morning *yawn*

 

For me personally those temperatures would be a little too high for 24/7 use. It could reduce the live span of your chip a little bit, or you might have to clock it down after a few years because it might no longer be stable then. If you want to risk that, is up to you, the overclock should at least not damage anything immediately.

 

The temperatures would be a little lower, but the ambient is sky rocketing here because summer is coming, but at night it's still pretty cool, and that's when I do the most gaming anyways. I have EIST activated so in idle the CPU will clock down and decrease voltage slightly. Idle temperatures are a little higher than I would like (36, 33, 34, 31), so I'll see how that works out. Otherwise, my overclock went 24 hours stable on Prime95, so I think I'll leave it at this setting for a while. I had a Q6600 at 3.6 for a year I think before I had to clock it down, and the temperatures were way worse then XD

I think if you increase the voltage on the chip you immediately start "reducing" the life span of the chip, but then again, a processor typically has a much longer life than our upgrade cycles are, even overclocked, so all's good

What I'm more worried about is the QPI/Vtt voltage. I read somewhere that Intel's official guidelines were not to cross 1.15V, and most definitely not 1.25V, but in other forums I read that it's just fine. What do people know?

 

My 860 is currently at 4.2GHZ with 1.34v, temps are a bit lower than yours (water-cooled). I'm hoping to get 4.4GHZ out of it in the near future.

I'm not exactly Bodar when it comes to overclocking, but I would have said that your OC is fine, temps are fine and voltage is prob to the higher end of the scale but fine.

 

Wow 4.2GHz... So close yet so far away ><

Thanks for your input Alec. I might try to lower the voltages a bit but I tried 1.35V and it couldn't POST properly, and I bumped it up to 1.375V to make sure it was a stable clock. When I'm done with my damn research paper (oh college...) I'll be able to tinker around a lot more.

I figure you're able to use a lower voltage because of water cooling and that the 860 is clocked higher anyways, but damn, 1.34V is an awesome voltage for 4.2GHz overclock, nicely done sir.

 

Yeah it goes without saying that watercooling is a huge benefit for high end over clocks (so why I just said it I have no clue lol) but good luck with it and keep us updated!

 

Maybe offtopic but does OC'ing also have to do with you're PSU? cause i can't even overclock 2,7ghz or my PC ain't starting up anymore :thumbdown
(my motherboard has an automatic overclock feature) Everything in my PC is fine, but my PSU kinda sucks...

i always wanted too OC, but i always fail at it :bang:

 

Yes it does have quite a lot to do with your PSU actually. When you overclock, more power is required by whatever component you are overclocking. If your PSU can't deliver the required power, then you're facing an inevitable crash. If I'm correct in assuming that you have the Amacrox AX500-A, then you don't have enough power for you rig. Hilbert recommends at least a 500W PSU for the 5850, which you have, you but also need 40A combined on your 12V rails, of which you only have 31A. Your PSU might not be enough support your system at stock speeds, let alone overclocked.

Now I might be wrong about your power supply model, but I briefly checked the Amacrox website and couldn't find much specifications, so I went with the AX500-A assumption. You should check how many watts are available on your PSU's 12V rails via the sticker on the side of the PSU. If the combined value is >40 then your good. Otherwise, you need to seriously consider getting a new PSU for your system to continue functioning. There are A LOT of good PSU brands out there, but still do some research before you buy anything, just in case you end up with something you don't like. It's happened to me more than once I can tell you.

Anyways, back to my overclock, it crashed today because the temperature here jumped to 28 Celsius, which was apparently enough to upset the overclock. It's friggin April but apparently latitudes work different for Illinois. Isn't it supposed to warm up loads till the end of May? So it seems until I find a stable lower voltage overclock, I'll boot stock clocks when the sun's up and use the 4.0GHz clock at night. *sigh* C'est la vie ><

 

Hey this seems like a good question.
I started testing my new chip.

I Have it stable and 4.2Ghz.

Temps : 38C IDLE and 68C Full load.

Cooling : Scythe Mugen 2 rev.b



But i have few questions :

1. What are the safe load/idle temperatures for this cpu?

2. What is the maximum safe voltage ?

3. Any reports that i5 ( Lynnfield that is ) will degrade like Wolfdale when you put too much juice on it ?

4. My volt in bios is set to 1.36v , why CPUZ is showing higher?


PS. I Got it booted at 4.9Ghz but it doesn't seem reasonable with 1.49v...

 

^Super chip

 

Holy crap Kapu, that really is a super chip considering you're on air cooling and all, well done. ><

As for the safe voltages, according to Intel, the CPU should not pass 1.55V and the Vtt/QPI 1.21V for the CPU not to degrade beyond repair, ie. not operate at stock clocks and voltages. I'm sure you can pass those voltages if you have adequate cooling, and with 68 load temperature, I think you can push it more if you really want. As for the the Vtt/QPI voltage, I currently have it set at 1.21V. I found that tweaking this value is instant win for overclocking. Despite Intel's specifications, my motherboard only starts warning when I past 1.23V, and some quick searching that most people overclocking usually set this value way past 1.21V, so I'm not to sure on the validity the actual safe value for that.

To answer your third question, any chip will start degrading as long as it's being used. A higher voltage simply speeds up this process. Even so, a moderate overclock with adequate cooling will still last for a long time, and mostly a lot longer than the upgrade cycle for most overclockers who use this forum, haha. Besides, your load temperatures are perfectly fine, and actually a lot lower than mine. Your idle temperatures are a bit high, but I'm guessing that you don't have EIST enabled to downclock your CPU when idle?

Finally, as for your voltage discrepancy, ASUS has been known to use system monitor chips that read out values a lot differently than from what's set in the BIOS. In that case, trust your BIOS values, since they have to be right (or else your BIOS is just messed up, which I hope it isn't, lol)

I'm curious as to how you tested stability though. Did you use Prime95? If so, for how long? The sad part of overclocking is that it might not be as stable as you hope it would be

 

For stability i tested Prime95 for 2 hours and about 2-3 Hours of Bad Company 2 gaming (multiplayer).

Also the air cooling isnt bad, acutally i was shocked by the performance of my

Scythe Mugen 2 , trully awesome cooler, well invested money if you want silent PC and mild OC.

As for degrading, i'm not thinking overtime degrading , i'm thinking wolfdale degrading when people killed chip in one hight with too high voltage , you can try gooogle it , it was quite common - I hope Lynnfield doesnt have this issue.

Anyone i'm having it clocked to 3.4Ghz (after turbo) since higher clocks right now are pointless with my pathetic GPU .

THough i wanted to play with the chip, wanted to see how far it would go.
and 4.9Ghz was my highest boot (i doubt it would be stable).

Anyway, i'm saving overclock for later ^^ LIke in a year or something when it will be needed

 

I was told that for decent stability, you should run Prime95 for at least 8 hours. That or just run IntelBurnTest, which rapes your CPU and heats it up like lioness in heat and does it in 20 minutes Obviously the 20 minutes doesn't prove jack, so I just do 15-20 runs on standard to make sure it doesn't crash immediately, find the settings I like, and then run Prime95 overnight to be sure.

I didn't know about the Wolfdale burnout, but I haven't heard anything in relation to the Lynnfield or Nehalem chips. Besides, even if you clock the CPU at a really high voltage (ie way beyond recommended levels) and run the chip without proper cooling, you'll be hurting the chip a lot in a lot of bad ways XD But if you don't keep the CPU at the high voltage for too long, it shouldn't get warm enough to destroy too many transistors on the CPU and should be fine after you lower the voltages.

With such a decent overclock, you definitely need to invest in a good video card to make up for the awesomeness pumping out of your CPU, lol. By the way, what are your RAM timings at?

 

They are at 1.55v (default 1.65) but 1350Mhz if i'm not wrong , their default clock is 1866.

Ram timings are : 9-9-9-20-68-1T Command.


As in CPU-z.

Should i lower them ? Possibly more performance but i'm bit skeptical to ram timings and performance

 

Those temps in IBT are a little high. I wouldnt be happy with anything over 80 degrees, but that is my personal preference.

Although depending on how you use your pc, you will probably never stress it like IBT does so you probably will never hit those temps.

 

@Kapu
Your timings seem a bit high for a 1350MHz clock, even with a 1T refresh rate. But then I'm actually not that familiar with RAM overclocking and I was hoping that you'd know more about it which was why I asked, haha.

@Ji1986
Yah I'm not too worried with the IBT temperatures since there's no way in hell I'd be able to stress my CPU to reach temperatures like that under normal usage. If it were to get too warm then I'd just go back to stock clocks. I only game really, and nothing too intensive generally, so it's cool

 

From what i know and personally tested , timings have very little effect performance impact.

I would rather go for stability and power saving than maximizing performance for little or no gain.

 

ZewoT were did you get the info that said the i5 750 could take 1.55 vcore?

From what I can find out says its recommended max vcore is 1.4V?

Just curious, since I'm hoping your source also says I can run my Q9450 @ 1.43 volts for a stable 4.0 ghz OC^^ :banana: