I just put together a software RAID5 volume on my new home server. I've run Bonnie++ to get some numbers of performance and here's what I got.

Version  1.03       ------Sequential Output------ --Sequential Input- --Random-
                    -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
jane.home.rugmon 2G 36554  77 61335  18 28910  11 40009  81 72370  20 216.0   0
                    ------Sequential Create------ --------Random Create--------
                    -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
              files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
                 16 22995  99 +++++ +++ 24641 100 21661  97 +++++ +++ 21109  97
Hardware setup:
AMD Sempron 3200+ (AM2 Version)
1GiB DDR2-800
Silicon Image 3124 SATA Controller
1x Seagate ST3320620AS 320GB SATA II HD
3x Western Digital Caviar SE16 WD3200AAKS 320GB SATA II HD

RAID Information:
mdadm RAID Level 5
4 drives, no hot spare
Total Space: ~892 GiB

Now I'm curious what others might get. I haven't had a chance to get my main system back up and running, not to mention it's got a degraded hardware RAID5 at the moment.

Install bonnie++ and run bonnie++ in a console. Post your numbers along with a little about your drive setup. If enough people post their stuff, we can get an idea of where we stand compared to others in the disk performance arena.