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AGP+PCI multihead, attempts two and three

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17th Jan 2006 | 12:58

Following on from <http://www.livejournal.com/users/fanf/44881.html>, <cam user=jpk28> kindly lent me a couple of non-Mac PCI graphics cards to see if I could get any further with them.

(2) 1995-vintage S3 Vision968

This was amusing. The card is only a little bit more recent than my 1993-1994 gap year at inmos, where at the time they made palette-DAC chips for graphics cards and had a respectable share of the market. However this card has an IBM DAC, not an inmos SGS-Thomson STMicroelectronics one.

Xorg -configure took rather a long time to run, and this turned out to be because it thought there were 110 S3 cards in the machine and enormous numbers of PCI buses. I edited the generated configuration file to be something more reasonable and tried starting X. The machine wasn't very happy about this: X sort of hung (I can't remember if I managed to kill it or if I had to reboot) and the ethernet card lost its interrupts. Not much success there at all. Since the card has a practially useless 2MB vRAM, I gave up fairly quickly.

(3) 1997-vintage ATI 3D Rage Pro PCI

By the time of this card, separate palette-DAC chips were a thing of the past. It has 4MB vRAM which is just barely tolerable.

The Xorg ATI driver claims that it should recognize this card as a Mach64 series card, but it doesn't, and X instead falls back to the VESA driver. DDC manages to get useful information from the monitor, which is good, but it autoconfigures with too many pixels to be able to maintain a decent refresh rate. 60Hz is nasty.

Multi-head X almost worked, except that when I moved the pointer to the secondary screen it disappeared. Juggling things around (virtual positions of screens, primary/secondary numbering) didn't improve matters - sometimes the VESA screen would have a corrupted display, sometimes X would get confused about where the boundary between the screens was (mouse pointer appearing 1280 pixels from the left of the 1600 pixel screen). I could run X on one screen at a time fine, but not both together.

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Comments {3}

The Bellinghman

from: bellinghman
date: 17th Jan 2006 13:36 (UTC)

"barely tolerable"?

Thanks - I do need to upgrade this machine's graphics. That is exactly the card in this PC, and I can't actually get 1280 x 1024 x 32 out of it - I'm limited to 24 bit colour at that resolution.

It'd make an abysmally bad gaming machine, but as a work PC, the card is (mostly) fine. An 8MB card would be almost be enough for what I want, which is 1920 x 1200 x 32 (as and when I can persuade the powers to let me have the monitor, of course).

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Tony Finch

from: fanf
date: 17th Jan 2006 13:43 (UTC)

Hmm, actually you've pointed out another anomaly - why was it running in 16bpp mode when it had enough RAM for 24bpp? (I miscomputed its capacity when I last wondered about that.) Hmm, perhaps this Radeon 9600 is to blame, because it's running single-head in 1600x1200x16 despite having 128MB vRAM and despite my xorg.conf saying 24bpp. Grr.

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The Bellinghman

from: bellinghman
date: 17th Jan 2006 14:17 (UTC)

Hey, the RAGE can do 1600 x 1200 x 16 with 4MB - I'm not sure why a 9600 should feel unable to go beyond that with a mere 32 times as much RAM.

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