i5 750 overclocking question

[evilbix]

Well.. I've reached 3.8ghz on air at 1.15V, stable on prime95 for 8 hours. Hit max temps of 67, 65, 61, 61. I'm wondering if I should push past the 4ghz barrier or is there a point of diminishing returns on the OC? I don't really want to up the volts and temps much if the gains are going to be less than 5% or so.

 

[The Sauce]

You have lots of room on the voltage, not a lot of room on the temps. I wasn't hitting those temps until I had it up to 4.2 GHz and 1.35V. Are you using the stock cooler? I probably wouldn't try to go much higher than that for 24/7 unless you upgraded your cooler. Would be useful to post your system specs.

BTW - Prime 95 stable for 8 hours = LinX stable for about 4 minutes. Test with both but for a quick answer while ramping up an overclock, LinX is the way to go.

 

[Kenmitch]

I'd upgrade the cooler those temps seem kinda high for such a low voltage....I'd guess stock cooler

I like to use Intel Burn Test first as it'll error very quickly and it's a great cooler tester

As far as the point of diminishing returns just judge it by how much voltage it takes to make the next jump in clockspeed. At some point you will have to start upping the voltage quite a bit to make the next jump. This is the point when you decide is the xtra voltage your pumping in worth the xtra mhz you achieve. Every chip has it's sweet spot you just gotta find it.

 

[The Sauce]

750 is funny with the sweet spot. On every prior chip I have found that spot no problem. On the 750 I find a fairly linear increase in speed with increasing voltage over the 4 GHz range - i.e. 4GHz @ 1.3v, 4.2GHz @ 1.35, 4.3GHz @ 1.4v, 4.4GHz @ 1.45V. Didn't go higher because of temps but never quite hit that point of diminishing returns and sorta felt that I could just keep increasing voltage and going higher. Makes me think this chip would be very scalable with extreme cooling techniques.

 

[iluvdeal]

I'll second that rec on LinX, your temps will go higher and you'll get a failure relatively quickly compared to Prime95.

Regarding overclocking efficiency on the i5-750, I'd recommend reading this article: http://www.tomshardware.com/reviews/core-i5-750-efficiency,2500.html

 

[Kenmitch]

Use Intel Burn Test to find your limits quickly. It will error out very quickly compared to prime. I always use this one first then move on to OCCT. Most of the time if it passes IBT then it passes OCCT. Sometimes ya gotta bump the voltage a tic or 2 to pass OCCT tho. Once you pass OCCT then try prime if you wanna but most of the time you can just skip it.

Also it's great for testing your cpu cooling

I'll make up some numbers so you get the point. Say idles at 40*c and shoots up to 80*c's in just a couple of seconds if your cooling solution doesn't cut the mustard

 

[mav451]

That's a nice stock vcore overclock. If you are using it for gaming, you may need to bump up the VTT a tad - or not. But 3D stable will usually take just a smidgen more. Regardless, looks like you got a good chip.

And agree with everyone else - your temps are on the high end considering you aren't even over 1.2vcore.