HP Desktop Centos installs

I picked up a couple HP desktop machines to beef up my garage datacenter recently and came across some very different experiences while installing Centos 5.3.
On the HP a6700f, which goes for about $500 with a quad core AMD phenom at 1.8Ghz, 4Gb memory, and a 500Gb disk, the Centos install went beautifully. I had a running linux server in a matter of minutes with everything picked up and running as expected.
Later, I had needed one more machine and was at Frys where they only had the HP a6720f. It’s a bit more expensive, but comes with a 2.2Ghz AMD Phenom and 6Gb of memory. However the install on this box was a completely different story, almost nothing worked. The motherboard is slightly different and the ahci driver couldn’t pick up the sata harddrive. The install would hang for awhile and if you checked the alt-f3 screen you could see that the driver was failing while trying to communicate with the harddrive. Using Google, I was able to determine that at the install prompt you needed to add the param “pci=nomsi”. With this the harddrive was picked up properly, but uses the device-mapper driver instead of the normal /dev/sda. I haven’t noticed any performance difference though.
After I got the machine installed on the now functioning disk I realized that the on board Gig eth card hadn’t been picked up. A trip back to Google and I found that on this chipset that the on board ethernet is not supported yet with linux. So a quick jump to amazon to pick up a Intel PRO/1000 PT dual Gig eth adapter and I had a fully functioning server.
I would definitely say that the while overall the HP “a” desktop line is great for an ultra cheap linux server, the a6720f is just not worth the headaches. Pick up the a6700f instead.