Bootloops past 4.4GHz with GA-Z68XP-UD4 and 2500k

[nissanman]

Hey everyone!

Earlier this year, I built my new PC using an Intel Core i5 2500K CPU and the Gigabyte GA-Z68XP-UD4 motherboard. The system works very well and runs every game I throw at it. However, along with the CPU, I also bought the Corsair H100 as I wanted to push the CPU to its limits. I currently have the CPU at 4.4Ghz and it is running fine, but whenever I try and go any higher, no matter how much more voltage I give it, the system will boot loop every now and then when I turn it on. This is an issue for me, as I was hoping to push my CPU alot furtherer. Anyone else with this board experiencing the same issue? I updated to the latest BIOS revision but am no closer to solving this problem.

The rest of my System specs are as follows.

8GB Kingston HyperX DDR3 1600 memory
Corsair HX650W
Radeon HD6870 Crossfire (Problem occurs with 1 card installed also)
60GB OCZ Agility 3

My CPU also seems to require an abnormally large amount of volts to remain stable at 4.5/4.6 in Windows. Like 1.45v. This just doesn't seem right to me. Any clues?

Thanks

Nathan.

 

[bluebob951]

Just a bad cpu, it can happen. how many month has your computer been running? when I first got mine early last year my 2500k only ran at 4ghz stable. Anything higher I would have needed like crazy 1.4+ volts. Now after long burn in sessions and using the computer for over a year now I can hit 4.5Ghz at 1.36 volts. It might just be a dud cpu for overclocking, it can happen it's just a luck of the draw. It shouldn't be the motherboard, it's a good motherboard with pretty clean 16 phase power delivery. How hot is it running with the h100? what are the motherboard settings also, there might be some oc room left, somewhere?

 

[nissanman]

The CPU runs pretty cool with the H100. I don't really see it go past 55 Celsius in Prime95 with this 4.4Ghz at 1.36v. As for my motherboard settings, I believe they are all on the auto settings, except obviously for the vcore and the multiplier. I have tried messing around with other settings to no avail. The computer has been up and running since February and since then (forgot to mention previously) I have sent the motherboard back for a replacement, so the problem shouldn't be that. It probably is just a dud CPU which is unfortunate, but I guess it happens.

 

[dividebyzero]

More than likely a board problem. Gigabyte boards are competitively priced here, and as such I had quite a bit of build experience with the Z68's. More than a few exhibited the same problem you are describing ( I tend to add the info whenever I give board recommendations). The behaviour ranges through the whole product stack -from the budget boards through to the UD7, and generally included needing a higher Vcore, VTT and a higher level of LLC compared with other vendors and the Gigabyte Z77's- which are much better behaved.

 

[nissanman]

After doing a bit more reading, I have found that this problem is occurring with quite a few people, not necessarily using a Gigabyte motherboard, but all of them are either Z68 or P67. Leaves me wondering if it could be a problem with the chipset.

 

[EXCellR8]

Hmm, I know a few people who run these boards (or similar) and have their processors running a little faster without any issues. I actually just helped out a co-worker with his. I believe we had his chip (not sure if it's the exact same CPU) @ 4.6ghz but I can't remember where we capped the voltage. I haven't done a lot of tinkering with 2nd and 3rd generation i5/i7 chips myself, but from what I've heard some chipsets may require some trickery. Since you've already updated the BIOS try fiddling with some of the CPU features and see if that helps. Also, make sure your RAM is set at the default speed and check the timings. Memory issues will cause boot loops all day.

 

[nissanman]

Quick update. I am now running my CPU stable at 4.5Ghz with 1.38v. That voltage still seems a little high for a 4.5Ghz overclock to me, but it is ok I suppose. So the porblem definitely occurs at 4.6Ghz or over. Not all the time, but enough to stop me from overclocking any higher. Reading a review of this board, the reviewer managed to get 4.9Ghz stable out of a Core i7 2600k.

 

[bluebob951]

Sounds very similar to my cpu, guess we just got dud cpus for overclocking. What's your V-droop when the cpu is under load? What did you end up changing to get it stable at 4.5Ghz?

 

[nissanman]

I just changed the multiplier to x45 and bumped the voltage up a little. I use the offset vcore setting. At idle in the bios it says 1.404v, but under load CPUZ reports 1.38v, so I guess that is how much vdroop I have. But because I used the offset, it idles at around 1v in windows.

 

[bluebob951]

1.4 is fine since you're under water and as long as the temps stay within the thermal limits you should be fine. A 4.5Ghz overclock is perfectly fine, I'm sure one you really burn everyhting in you might be able to squeeze another .1-.3 ghz out of the thing.