On 10/27/07 8:56 AM, "Jukka Marin" <jmarin@embedtronics.fi> wrote:

> Question: Why is RAID5 this slow?  Is it a NetBSD problem (in the twa driver,
> for example) or is this how RAID5 performs?
> 

I have a system with 2x3G xeons, wm's, same 3ware card (my firmware is a
little newer/or different):

3ware 9550SX series: (rev. 0x00)
twa0 at pci3 dev 1 function 0: 3ware Apache
twa0: interrupting at ioapic1 pin 0 (irq 10)
twa0: 12 ports, Firmware FE9X 3.04.01.011, BIOS BE9X 3.04.00.002
twa0: Monitor BL9X 3.01.00.006, PCB Rev 032 , Achip 1.70    , Pchip 1.60
twa0: port 0: WDC WD2500YS-01SHB0                      239372 MB
twa0: port 1: WDC WD2500YS-01SHB0                      239372 MB
twa0: port 2: WDC WD2500YS-01SHB0                      239372 MB
twa0: port 3: WDC WD2500YS-01SHB0                      239372 MB
twa0: port 4: WDC WD2500YS-01SHB0                      239372 MB
twa0: port 5: WDC WD2500YS-01SHB0                      239372 MB
twa0: port 6: WDC WD2500YS-01SHB0                      239372 MB
twa0: port 7: WDC WD2500YS-01SHB0                      239372 MB
twa0: port 8: WDC WD2500YS-01SHB0                      239372 MB
twa0: port 9: WDC WD2500YS-01SHB0                      239372 MB
twa0: port 10: WDC WD2500YS-01SHB0                      239372 MB
twa0: port 11: WDC WD2500YS-01SHB0                      239372 MB
twa0: AMCC    9550SX-12  DISK 3.04Y15328213EF9A6000FC2

But I am running netbsd-3-1 with an MPBIOS kernel.  I can support I/O in
excess of 30MB/s sustained.  The same system dumping from NFS to local disk
sees that speed as well. I have multiple jobs running when I get my rates
(via bacula) so don't use this for max estimates.  It's a good baseline
though.

peter