Can't overclock 2500K on Z77A-GD55

[WooZ]

Hi.
I can't manually overclock 2500K on Z77A-GD55 but which OC Genie @4,2GHz all works perfectly fine.

When I try OC to 4.2GHz with 1.35 same as OC genie I can boot for first time and it is stable under 2h OCCT but after switching off system i can't even post.

All time first boot fine and stable but second time can't even post. I tried everything clear cmos, flashed bios to latest version, OC guides everything with no success.

My specs are in sign.

[MadMarc]

If you are happy with 4.2 GHz, just let OC Genie do the job, otherwise I'd first try with 4GHz and then go up from there, although you should easily get 4.2 on a 2500k with decent cooling

[WooZ]

Originally Posted by MadMarc

If you are happy with 4.2 GHz, just let OC Genie do the job, otherwise I'd first try with 4GHz and then go up from there, although you should easily get 4.2 on a 2500k with decent cooling

At 4GHz first boot fine but second boot fail.
I even can OC to stable 5GHz max temp 75 but second boot fail and that happens with any manual OC.

[yassarikhan786]

Have you disabled CPU PLL Voltage?

[Josh Weston]

1.35 should be enough 4.8GHz, let alone 4.2
What are you using to overclock? Are you going through the UEFI, or are you using one of the software implementations MSI give you?
Also, have you got the latest BIOS?

[WooZ]

Originally Posted by yassarikhan786

Have you disabled CPU PLL Voltage?

No. But I will try. Now its working but now when I press power button it will try post then shutdown and with second try it boot to windows.

Originally Posted by Josh Weston

1.35 should be enough 4.8GHz, let alone 4.2
What are you using to overclock? Are you going through the UEFI, or are you using one of the software implementations MSI give you?
Also, have you got the latest BIOS?

Through the UEFI.
Yes. I have 1.5 version.

[Perturabo]

I would check that your overclock is actually applying on your first boot. Run Pi fast to check that it goes faster at 4/4.2/5 GHz. It may be that the OC just doesn't apply until the second boot for some reason, making it appear stable when it isnt.

[Josh Weston]

It may be worth reflashing your BIOS. I had some instability issues when I flashed my BIOS to the latest one, another reflash and I was sorted.

[WooZ]

Originally Posted by Perturabo

I would check that your overclock is actually applying on your first boot. Run Pi fast to check that it goes faster at 4/4.2/5 GHz. It may be that the OC just doesn't apply until the second boot for some reason, making it appear stable when it isnt.

Disabling PLL voltage I can boot with second attempt.
Super PI 8M results:
Stock speed - 1m 58.960s
OC Genie 4.2 GHz - 1m 44.100s
Manual OC 4.7GHz - 1m 33.760s
Manual OC 4.7GHz 2nd boot - 1m 33.700s

Originally Posted by Josh Weston

It may be worth reflashing your BIOS. I had some instability issues when I flashed my BIOS to the latest one, another reflash and I was sorted.

I already re flashed bios but I can try again.