Help a rookie OCer keep from burning up!

[mundanesoul]

Hi all,

Decided after doing some research that I would try to do a modest overclock on my i5-4670K since I'm getting ready to throw a new GPU and some extra memory into my machine. I actually put a 212 EVO on my CPU back when I built this PC back in 2014 in case I decided to give this a shot.

However, after bumping by multiplier up to just 40 from 34 (I didn't modify anything else), I'm getting up into the high 80s when I do a Blend test in Prime95. Do you all have any idea what could be causing this huge jump in temps? Did I just lose big time in the silicon lottery or am I totally missing something obvious? My build is included for reference below. Let me know if you have any ideas where the issue might lie. And thanks in advance for your help!

Intel Core i5-4670K 3.4GHz Quad-Core Processor
Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler
Asus Z87-Pro ATX LGA1150 Motherboard
G.Skill Ripjaws Series 8GB (2 x 4GB) DDR3-1600 Memory
Gigabyte GeForce GTX 770 4GB WINDFORCE Video Card
Corsair 500R Black ATX Mid Tower Case
Rosewill Capstone 650W 80+ Gold Certified Semi-Modular ATX Power Supply

 

[Lochekey]

What is the voltage set at? If it is on auto it is probably giving way to much voltage.

 

[mundanesoul]

Ah, okay. I can't check at the moment, but I will look into this. Do I need to set it to a static value?

 

[trents]

What version of Prime95 are you using? The newer versions use AVX2 instructions and generate an inordinate amount of heat. A lot of people are using other stress testers such as AIDA64 Extreme, Intel Extreme Tuning Utility or Realbench to test for stability without generating excessive heat. Another option is using an older version of Prime95 such as 27.7 that doesn't have the AVX2 instruction set.

It may also be time to redo your TIM. It may have dried out or pumped out. And what about dust buildup in the heatsink? Have you checked for that?

What about case ventilation? Is it adequate?

 

[mundanesoul]

Thanks for the tips, trents. I was thinking I might grab some thermal paste to see if that makes a difference, and I'll check for dust in the heatsink.

Case ventilation should be good, I've got fans in the front, back, and side panel that are all running full bore.

I saw some of the talk about newer versions of Prime95, too, so maybe that's part of the issue - I'm using the latest version. Should I feel confident if I get better scores in AIDA or an older version of Prime? And what kind of temps do you all think I should feel confident with? I saw a pretty wide range out there, but general agreement was that over 80 was bad news, so I knew I was in trouble there.

 

[trents]

90c or under is safe for extended periods. Thermal throttling sets in at about 100c.

I have found that passing 2 hr. of Prime95 demonstrates sufficient stability in an overclock to give confidence but using AIDA or XTU I would go at least 5 hr. (I usually just set it for 8 hr. overnight while sleeping). Realbench, maybe 4 hr. OCCT large data set, 3 hr.