On Fri, May 06, 2005 at 10:14:50AM +0200, Joel CARNAT wrote:

> Now that my U5 is up and working OK for 15 days (with 2.0.2), I wanted
> to swap the IDE disk to an SCSI one. I have two differents cards :
> - esiop0 at pci2 dev 1 function 0: Symbios Logic 53c875 (ultra-wide scsi)
> - isp0 at pci3 dev 4 function 0: QLogic 1020 Fast Wide SCSI HBA

Is that a Sun card or directly from QLogic?  I wasn't aware Sun sold 1020s,
just the 1040s.

> Both seem quite old and I just can't find docs about their specs, neither
> on Google, nor on docs.sun.com :( All I know is that the QLogic also has
> an ethernet port.

The glm (Symbios card) can do faster bus transfers.  The isp is an extremely
intelligent card and is capable of doing >1 interrupt/command.  (Yes, I do
mean multiple commands/interrupt.)  So which one you want to use depends
on the speed and number of drives on the SCSI bus.  If you have drives that
can support ultra speeds and can transfer more than 20MB/s sustained, 
you probably want to go with the glm.  If you do mostly sequential I/O
the glm is probably better.  If you have slower disks or multiple disks on
the spindle, the isp may be better.  If you do lots of random seeks then
the isp will definitely be better.  And if you are CPU bound, definitely
go with the isp.

Eduardo