Promise SX8 driver performance

Matt
2004-11-29T19:59:16Z

Hello all. I've got a Promise SX8 SATA controller and the performance
seems a little off. I'm using a debian-built 2.6.9 kernel and the
read/write I/O seems to level off around 80-90 MB/s. When I use the same
hardware in Windows, sequential I/O goes up to 218 MB/s. (That's about
the limit of my motherboard's buses.) If I move some disks to the
on-board SATA controller, I can get the I/O to go higher but never as
high as in Windows.

Is this a problem with my expectations, my testing, or the driver?

Some Bonnie numbers for a raid 0 array of Seagate 7200.7's (2 GB file,
sequential, MB/s):

Disks/cntl Write Read
----- ----- ----
1 (sx8) 57 63
2 (sx8) 69 75
2 (ESB) 111 121
3 (sx8) 75 79
3 (1 sx8, 2 ESB) 141 125
4 (sx8) 89 80
4 (2 sx8, 2 ESB) 135 150
5 (sx8) 88 79
6 (sx8) 91 75

Some numbers from Sandra (ugh) in W2K Pro with the latest Promise
drivers and using software RAID 0 (sequential, MB/s):

Disks/cntl Write Read
----- ----- ----
1 (sx8) 56 62
2 (sx8) 106 122
3 (sx8) 151 176
4 (sx8) 178 209
5 (sx8) 180 218
6 (sx8) 179 218
6 (4 sx8, 2 ESB) 169 207

My full hardware:

Supermicro P4SCi motherboard (7210 chipset, 6300ESB SATA on-board)
3.0 GHz P4 Northwood w/ HT enabled
(2) 512MB DDR400 dual channel (non-ECC)
Promise SX8 SATA controller
(6) 200 GB Seagate 7200.7
(1) 40 GB Seagate Baraccuda IV (boot)
Adaptec 2940U