Hi there. I have the same mobo (4Gig Ram and an 8800GT) and have been running leopard stably for over a year keeping it fully patched. Snow is proving more of a problem however.

I did find 1 user of the board Kramer2k talking about the same mobo and I got the following from him; (All kudos to kramer2k for this info - Hope you don't mind me sharing it!)

*****************************

SL works really well on the P31.
Only kext's that I've added are fakesmc, OpenHaltRestart, and ApplePIIAXata (or however it's spelled) from Netkas I think (I can get you the one I use if you're interested). I don't remember if I'm using a modded AppleHDA or not...

I tried a couple installs. I first did it via my Leo install using OSInstall package. It worked ok, but I had errors (that were correctable) with Disk Util and permissions, and the files under / weren't hidden correctly (also an easy fix).

The install I'm currently running (10.6.1) was installed off of a USB HD with the SL DVD restored to it. I booted from a USB stick with Chameleon RC1 and EFI 10.1, My DSDT.aml, fakesmc, openhaltrestart, applepiaaxata. Install wasn't an issue.

I've since modified my DSDT to include the following
-Built in ALC888 (again, I don't remember if my AppleHDA is modded, I think it is)
-Ethernet with TM fix (not sure if needed, as network works OOB)
-Video - 8800GT 512MB
-USB - Shows as built in. Problem is that devices that are USB2 (EHCI) can't wake from sleep. USb1 devices are fine. for example, I can't wake using my apple alu keyboard, but my wired logitech mouse wakes it fine.
-I also added a value so that PCI devices show under system profiler.

what else, what else...
Oh, the other issue I've found is that SL is particularly sensitive about permissions on extensions.
For example....
SL will NOT boot to 32 bit mode if there is not an extensions.mkext in /Extra
SL will NOT boot in 32 bit mode if permissions are not correct on extensions.mkext in /Extra (this is fixed by using kext helper for SL)

SL will boot 64 bit without an extensions.mkext in /extra
SL will boot if extensions aren't exact either

I think this all might be a bootloader issue, but I haven't tried either RC2 or RC3 or 10.3
So the way around it is if you can't boot into 32 bit mode, you've got to boot in to 64 bit mode, run kexthelper to rebuild your /Extra/extensions.mkext, then boot back into 32bit mode.
It's REALLY particular to that file in 32 bit mode.

Phew, makes it seem like a lot...and it probably is, but it's all just a labor of love since 10.4.1

Oh, and upgrade to 10.6.1 requires nothing special at all, install and reboot.

One last thing too (just seem to be thinking of things as I'm typing), Bonjour is fixed by using a script having to deal with promiscuity of the network, it's in the forums.

*****************************

I've been trying to combine this advice with sk1nhd33t 's guide to the Gigabyte G31 mobo and have now got a bootable USB stick but it KPs about 2-3 mins into the installer. (Suspect it may relate to postings that Snow only likes to install to a disk on SATA channel 0 - anyone able to advise on this?)

Kramer also kindly copied me his DSDT file but I'd prefer to check he's OK before I would UL it for public consumption.

I'll watch this thread for progress and will share any of my own. Hopefully we can both get Snowy up and running real soon.

baldrick45

PS - Thanks again Kramer2k - I'd have stuck with Leo and waited for IKAROS to eventually appear if not for all your help to date.