SB Motherboard Swap

[diver]

My old system was a P55 with an i5-750. I locally purchased a Gigabyte Z68MA-D2H-B3 motherboard and an i5-2500K for about $300 plus tax. Prior to doing the swap software was upgraded to Tony's latest version of Chimera, bridge helper and all the latest fakeSMC.

Prior to shutdown, I removed DSDT.aml from the extras folder. I could have saved myself some grief if I had copied the DSDT for the new board there. The machine KP'ed until booting with I boot and fixing that oversight. Make sure you set the bios of the new motherboard for ACHI and 64-bit hpet. The only other necessary software change was switching to the "official" Realtek lan kext.

I was able to utilize all of my remaining hardware. The old motherboard and processor will be used to upgrade a different machine.

My first efforts at overclocking are producing a Geekbench score of 11,800 using a base multiplier of 42. No other changes were made, although I set a few of the power saving features to enabled rather than auto.

The only CPU voltage adjustment on this motherboard is a voltage offset. I assume this can be raised or lowered if the automatically supplied value is not enough or too much.

For the time being I am leaving it alone. It is humming along in the next room with Prime95 at about 69c. Ambient is a warm 28c. I have not tested it yet with Linpack, but anticipate temperatures will be 5c higher.

I have not verified all power management functions but will do so over the next few days. Perhaps 10.6.8 or a new bridge helper will come along any day now and tweak things a bit.

 

[diver]

Running now with a 43 multiplier and a -.05 voltage offset for 1.296 V core. These numbers were used by Guru3d to OC a 2600k. Testing now with Prime95 on the 2500K but this is actually conservative as the i5 lacks the heat generating hyper threading option. Geekbench is at 12050. CPU temps are about 5C lower with the voltage adjustment.

Auto sleep works. I have not confirmed if speed step works. USB 3.0 shows up in the system profiler. Everything is working. I picked up another benefit in the upgrade. My Crucial SSD has a SATA 3 interface so that feature in the chipset is good for another 10 to 15% in SSD speed.

There are probably some more reliable ways to do this, like deleting the extras folder before shutdown, booting from iBoot and then running Multibeast. The important thing to remember is a fresh install of OS X is not necessary.

 

[diver]

43 multiplier was not stable.

After waking from sleep, turbo modes are disabled and geekbench drops to 9700, was 11800 before sleep. Have updated to 10.7.4 kernel and some power kexts from the iMac 10.6.7 update, but no change.


any ideas?

 

[diver]

After spending way too much time on it, I reverted to the F2 bios that shipped with the board and made the most minimal changes possible. AHCI, 64-bit, multiplier raised and turned off the full screen boot, nothing else. The problem went away and the overclock sticks after a sleep.

The F3 bios is either totally buggy or has a more limited bug related to some particular settings I used: V Core offset, quick boot, disabling serial port, disabling fan control.

That should not have happened.

BTW, this bug manifested under Windoze 7.

 

[diver]

Minor update: Power measured with the kill a watt is slightly lower now and idle temps are a few degrees C lower as well. Machine ran 2.5 hours of prime 95 with no voltage offset at slightly lower temps than yesterday and is now stable at 43 multiplier. Geekbench: 12075

DSDT downloaded here is supposed to be for the F3 bios, but it worked. I just switched to an Autopatcher DSDT extracted from the F2 bios. It also works. Perhaps there is no mission critical difference.

 

[Gordo74]

They are essentially the same, except the one in the database you do not have to use the Non DSDT audio enabler.

 

[diver]

They are essentially the same, except the one in the database you do not have to use the Non DSDT audio enabler.

I have audio with the autopatcher DSDT and the the non DSDT audio enabler is not being used. All I can say is that buggy bios cost me a lot of time.