On Sun, 15 Nov 1998, Dave J. Andruczyk wrote:
>
> This is probably a stupid question, but I have to know from the experts.
>
> Does using an ISA video card on a server, hurt its performance as a server
> (the monitor is ONLY used for text mode)??
>
> I want to pull the matrox millenium my server came with in order to use a
> Trident 9000 ISA card in order to free up a PCI slot for a 10/100 net
> card.
>
> I tried it briefly and noticed the memory check on boot going about 10
> times slower than it was supposed to so i quit there and stopped. Anyone
> have this happen?
>
> The machine is redhat 5.1+all errata, Kernel 2.0.35, Dual PPro200, DPT
> Adaptec 2940UW, bios 1.23 (Scsi0), 2144UW scsi (scsi1) D-link dfe-500tx,
> and an NE-2K isa clone. ITs been stable as a rock.
According to a nifty white paper I snagged on ATM on the PCI bus (see
www.phy.duke.edu/~rgb/linux.html -- it is linked there somewhere) the
dark side of putting an ISA card onto a PCI system is that it can (note
"can", not "will") screw up busmastering on the PCI bus. I think (as I
recall, but read it yourself) that this is because latency assumptions
have to be downgraded to handle the immensely slow ISA bus.
I don't think that this ends up being a problem with cards that generate
few interrupts, and video cards should be in that category, but I'm not
sure. Mixing ISA ethernet or ISA SCSI with PCI ethernet or SCSI is
probably a bad idea, though, in a server. And it may be that having ANY
ISA cards causes conservative assumptions to be automatically made that
effectively increase latencies.
rgb
Robert G. Brown http://www.phy.duke.edu/~rgb/
Duke University Dept. of Physics, Box 90305
Durham, N.C. 27708-0305
Phone: 1-919-660-2567 Fax: 919-660-2525 email:[EMAIL PROTECTED]
