View Full Version : SCSI Performance

09-07-2003, 03:36 PM
For some of the people who are getting very high 64 bit SCSI performance have you made any tweaks? I have 4, 10,000 rpm 72 gig u160 seagate scsi drives on the u320 controller in the X5DA8 MOB, each drive on it's own will do 45 to 50 MB/s however once I stripe these 4 drives I can not get the set to do more the 135 MB/s. A 2 drive drive set will do about 95 MB/s, it seems as if there is a limit some place in the system, I am running XP Pro and did find some registry settings for the aic-7902 drivers but have had no luck in upping the performance. : (


Jim Capillo
09-07-2003, 03:43 PM

Did you turn off drive indexing? Also, I've gotten huge differences in autoconfig results on my SCSI raid (68 mbs to 275 mbs or so) - even if I do autoconfig two times in a row..... that's why I tend not to pay too much attention to the results. My IDE raid is different.... always within a couple mbs of the previous autoconfig.

Go figure. :rolleyes:

09-08-2003, 01:59 PM
I always get consistent speed reports from Autoconfig, and you should probably be getting higher numbers with your setup.
I assume you have the 320 controller in a 64-bit slot.
If your drives are full and fragmented, this can have a large impact on speed.
Do a report on the fragmentation of the drive. If there is more than about 10% total fragmentation, it could be adversly affecting performance.

09-08-2003, 02:00 PM
Also, disable your anti-virus software while testing, or editing.

09-09-2003, 11:07 AM
Thanks for the input. After checking everthing over all configs and tweaks look good. The drives mentioned above are U160's. Can anybody else tell me what kind of performance you are getting with something similar to 4 10Krpm U160 drives on a 64 bit SCSI controller. For reference this drive set is running on a supermicro X5DA8 with 2 GB of ram and the on board U320 SCSI controller.