My setup is as follows:

Motherboard: Tyan S2895 CPU: Two Opteron 275s Memory: 4 GB Disk: Three 250 GB SATA drives attached to a 3Ware 9500S-4LP RAID card Video: Nvidia GeForce 7800

The only hardware that I have added to the motherboard is the 3Ware card and the Nvidia card. The disks are configured as a RAID 5 array, and the machine boots from this array. I installed CentOS 4.2 x86 on this system without any problems during the installation. The on-board sound card was recognised and the correct driver (snd_intel8x0) installed to handle it. However, on rebooting into the SMP kernel after the install, the installation proved to be completely unstable. The kernel would panic sometimes during startup and sometimes during shutdown. The uniprocessor kernel seemed to be stable, but I noticed the following error messages appearing on the console during startup (the same error messages also appeared when booting into the SMP kernel):

3w-9xxx: scsi0: ERROR: (0x03:0x0104): SGL entry has illegal length:address=0x37077000, length=0xFF, cmd=X.

Suspecting that there might be a driver incompatibility with my particular hardware configuration, I downloaded one of the Fedora 4 kernel sources from the 2.6.12 series, and compiled my own SMP kernel. This solved the stability issue, and I have been using this intensively for four months without experiencing any system crashes. Unfortunately, I have been unable to get the on-board sound to work. If I use XMMS to play an MP3 file (I have the XMMS MP3 plugin from the Dag Wieers repository installed), then on hitting the play button nothing happens. It is not that XMMS thinks that it is processing the file but no sound is being produced, rather the playback counter stays at "00:00". If I visit a web page containing a Flash animation with sound, Firefox locks up and has to be killed. I have compiled other Fedora kernels from source (2.6.14) and the same behaviour is observed. I also cannot get sound to work with the 2.6.9 uniprocessor kernel supplied with CentOS 4.2.

I know that the hardware on the motherboard is not faulty, because the machine is set up to dual-boot into CentOS or Windows XP. On Windows, there is no problem with the sound, and interestingly once I have booted into Windows if I then reboot into Linux then the sound will work under Linux (although sound mixing is still a problem - one application outputting sound will cause a second application trying to output sound to stall until the first is finished).

Has anyone on this list experienced the same problems, and if so found a way to overcome them? Failing that, does anyone have any suggestions for any tweaks I can make to my system to make the sound work without having to boot into Windows first?

Thanks, David Mellor.