Just can't OC 2500k in ML, no probs in SL & Lion... help!

[Thade]

Hi all, I have a Gigabyte GA-Z68AP-D3 v1 and i2500k. It is a decent overclocker & I know what I can hit in Windows, Lion, SL

I'm using the OC SSDT.aml from MB but 1 MHZ over 33 multiplier usually results in "still waiting for root device"

I have found a couple of post suggesting setting individual multipliers with the last multiplier 1 MHZ less:

42
42
42
41

... but it doesn't seem to help. I may be missing something simple here?

I've tried various combinations of multipliers

What's all that different about ML? I also have SL and Lion installed and they boot up fine whether I use the primary multiplier or any combination of individual core

any ideas?

tia

 

[Koalaman]

Did you delete NullCPUPowerManagement? And what Smbios are you using?

 

[Thade]

I never had nullcpupowermanagement. I am currently using Mac Pro 3,1 but I have also tried Mac mini: 5,1 & 5,3 with same results

 

[Koalaman]

Did you try:

43
42
42
42 ?

 

[Koalaman]

Do you have a DSDT/Modded Bios? And 42 to 41 isn't one megahertz lower, it's one hundred!

 

[Thade]

Do you have a DSDT/Modded Bios? And 42 to 41 isn't one megahertz lower, it's one hundred!

No modded bios, latest for my MB F8 patched for orange internal drives using dsdt autopatcher (also corrects unrecognized DVD player)
DSDT aslo edited for HDMI support Radeon HD6850

It IS actually 1 MHZ higher on the multiplier and I do understand that x 100 translates to 100 MHZ

I can't recall if I tried

43
42
42
42

I have tried many combinations but I'll give it a shot when I get home.

I am surprised that I'm in the minority here. Whatever the issue is here, it is clearly something specific to ML as I have had no probs with Windows, Lion & SL

 

[Koalaman]

No modded bios, latest for my MB F8 patched for orange internal drives using dsdt autopatcher (also corrects unrecognized DVD player)
DSDT aslo edited for HDMI support Radeon HD6850

It IS actually 1 MHZ higher on the multiplier and I do understand that x 100 translates to 100 MHZ

I can't recall if I tried

43
42
42
42

I have tried many combinations but I'll give it a shot when I get home.

I am surprised that I'm in the minority here. Whatever the issue is here, it is clearly something specific to ML as I have had no probs with Windows, Lion & SL

You're not in the Minority.

 

[Thade]

Just can't OC 2500k in ML, no probs in SL & Lion... help! SOLVED

OK guys... progress. It is very possible it boils down some difference in ML with hard drives. I had been using an old Seagate ST3250410AS 250 GB & I just switched to a Sandisk SSD for my ML drive and 2 major differences:

I can now use <key>UseKernelCache</key>
<string>Yes</string>

with the old drive KernelCache yes would cause still waiting for root device

Next, set the main multiplier to 40, did not mess with individual cores and haven't failed to boot properly yet.

This just could be some fluke bad hardware combination?!

 

[Koalaman]

Ah, interesting.

 

[Thade]

Ah, interesting.

out of curiosity, what hd are u using?