using isa - performance degrade?
hi all
i'm running 2.4.26 (debian) with sd's attached to an ncr53c8xx-scsi controller. since the sys is a p133 (the machine acts as a router/gw and knfs) performance isn't all the matters...but i was wondering..
if i would plug the vga-card to an isa slot(now unused& not compiled), one pci would get free to hold an AHA-2940 scsi controller, so i could split disks over the two scsihosts & add a few more.
will the additional use of the isa-bus give me a performance impact?
sym0: <810> rev 0x2 on pci bus 0 device 12 function 0 irq 10
Vendor: IBM Model: DNES-309170 Rev: SA30
ANSI SCSI revision: 03
Vendor: QUANTUM Model: FIREBALL1080S Rev: 1Q09
ANSI SCSI revision: 02
Vendor: QUANTUM Model: VP32210 Rev: 81H8
ANSI SCSI revision: 02
Vendor: IBM Model: DDRS-34560 Rev: S97B
ANSI SCSI revision: 02
another DDRS-34560...cdroms...
i won't have a problem with pci-throughput. afaik, with 33MHz-pci it shouldn't be a problem to get data from queries over the bus - those are not quite fast disks (hdparm -t 4,4MBs-fireball, 5,2MBs-VP,
Quoted 1 line
8MBs-IBMs). since i also heard about poor performance
of the adaptec-2940, will it be wise to use the second adapter?
another issue i'm poring about is using tagged command queueing(VP) / linked commands(fireball) on two disks holding a cache for squid on a reiserfs + swaps. will it improve performance or is the elevator/schedular enough? i know how to set command queueing at bootup but i'm clueless if there is a programm (scsi-tools? do i need sg?) to set various other options for the drives/host?
please cc to jkerdawn<at>yahoo.com
-i've been on the list for a while, but the traffic..=(
thanks a lot & regards
ritch.
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