G400 won't work in any non-Windows OS (horrible flicker, 1/2 sync rate)

[Gandalf007]

This is an onboard G400 in a Compaq BTW. It works perfectly fine in win2k, but is really screwed up in Linux and OpenStep. What happens is that in any graphics mode, it syncs at half the rate is thinks it's syncing at, so the image flickers horribly. At first I though this was a problem with the OpenStep drivers, but it happens under XFree86 (Linux) as well. For example, at 800x600, 100Hz (according to xvidtune) the OSD on the monitor shows 800x600, 53Hz (and it flickers like that). At 1024x768, 76Hz, it flickers much worse (as in it hurts my eyes), and the OSD won't even come up on the monitor (so I'm thinking it's running at 38Hz or so).

I tried flashing the Compaq BIOS (no change), and then the Matrox BIOS (refuses to flash, says Invalid BIOS). When I try to force it to flash with the undocumented switches given at the MatroX Files page, the flashing program crashes.

[Adariel]

Hi,

well, my G400 worked fine in Linux. Check your Xfree settings, perhaps it's checked the interleave option and thus you get half the rate. The other "quick fix", obviously, run at twice the rate you want.

Good luck.

[Gandalf007]

It's not the XFree settings -- I'm using the standard modes, and evey single mode is doing this. I upgraded to 4.1 and it's the same behavior as with 3.3.6 (and OpenStep 4.2). No Interlaced modes either. I'd like to think it's a hardware problem, but win2k works perfectly fine. What gives?

Edit: I tried 1024x768@120Hz, get 64Hz... but as far as the OS is concerned, it's actually doing 120.

[Kruzin]

Your best bet of getting help is going to be in our Alternative Lifestyles forum, where all the Linux users post.
This thread will be moved over there...

[Gandalf007]

Anyone?

I can get 800x600x16bpp@60Hz using the VESA driver under XFree86, but that's what it tops out at. I'd much prefer the MGA driver, but horrible flicker = ugh.

[Neptune]

Sorry, cant help you with openstep, but i'll make a try with linux.
To begin with, revert to the mga driver, tell us which distro u r using, what version of XFree and include your XF86Config.
It looks to me that your problem is your monitor setup under xfree and not the card.

George

[Gandalf007]

Trust me, it's not the monitor setup. I'd be willing to bet that if I took this XF86Config file to another machine with a different G400 in it, that it would work flawlessly.

The kernel framebuffer driver (mga) also exhibits the same behavior. 640x480@60Hz doesn't even work.

XF86Config file

[PeS]

Hmms, can you post here your XFree86.0.log, so we can see why it uses such obscure modes? Mine G400 is working great without problems...

[Neptune]

I'm looking at your XF86config...
What monitor do you have?
You have no Modeline entries under "Section Monitor" and, except if you have a 15" monitor, you Horizontal & vertical frequencies seem a little low....

[vana]

Behavior you see is normal for Compaq sold hardware. While everyone else uses 27MHz XTAL as recommended, Compaq uses 14.318MHz, and because of developers do not have Compaqs...

If you'll use Linux matroxfb driver with kernels 2.4.19-pre5 or newer, and XFree with
Option "UseFBDev" "on" and Option "HWCursor" "off", you should get correct picture.

But unless you do not want to use TVOut, just
multiple each value by 27/14.318, so instead
of 100Hz use 188MHz, and so on. Of course,
you must also increase your monitor capabilities
by same factor.

If you want TVOut, you have a problem: chroma subcarrier is derived from this frequency, and so it will use very wrong value under all non-WIndows OS I know.

Petr Vandrovec