problem with g400 (or monitor) - help

[Keith]

I recently purchased a new pc which included the matrox g400 dual head video card (32mb agp). I have a sony 200es 17" monitor. My old card (a cheap 4mb s3) displayed beautiful images on the sony monitor. The matrox card gives me a shaky screen. I've had to lower the refresh rate down to 60Hz in order to get a stable screen.

I'm running 1024x768 res in both cases.

The monitor has default settings of

1024x768 75Hz VESA
1024x768 85Hz VESA

and a max of 1280x1024 60Hz VESA

I've installed the latest matrox drivers and sony monitor inf but it hasn't changed anything.

Has anybody had a problem similar to this? Will this lower refresh rate cause problems when playing games?

[PurpleHaze]

hmm. Sometimes the refresh rates aren't exact. Go into the 'advanced' refresh adjust and tick it up and down by 1hz and see if you can get something that isn't hitting a harmonic, or whatever is causing your screen to shake. (you should be able to 'tune' around it) ...

And yes, if your refresh rate is 60hz you won't ever see more than 60fps... not that IMHO you need to, but still, 60hz is hard on the eyes.

[Keith]

I did try adjusting the refresh rate 1hz at a time but it did not help(much). The screen was still shaky, although at some frequencies the center was ok, but the corners of the scren were bad (shaky).

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-Keith

[PurpleHaze]

Have you moved the monitor since installing the G400? That's strange. I know the thing works okay on a 200ES. Same cable? Try putting the card in another slot, really. There are other variables, too... more intricate monitor settings, but i don't think any of them would cause the skaking you're describing. It sounds like RFI... Try moving the monitor away from the wall and test. Really. It may just be coincidental. Just give it a shot; if you're in an apartment or dorm room someone may have put a fan on the other side of the wall the day you got your G400. Because it doesn't sound like something the card could do.

[Keith]

The monitor has been moved slightly (I'm working on my old and new machines right now). Perhaps the cable is bent up against a wall (it is fairly close, although it was before as well). I'll give it some more room and let you know.

The cable is the same and I can't change slots because I only have one agp slot on the board.

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-Keith

[PurpleHaze]

Oh yeah. This is the real world, we're dealing with AGP these days, sorry.

Anyways. It probably isn't the cable being bent but the actual orientation of the monitor... The monitor could be getting inductance from an AC line in the wall or something... Move it around, turn it this way and that, pull it away from the wall, see what happens.

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Ami Y. Koriuchi - foxyviolet@hotmail.com
Asus P2B 1010 - P3-500 - And a G400Max now.
256MB 6NS 70 GB of 10k RPM SCSI UW

Mustard is illegal here.

[IceStorm]

Crank the refresh up to 100hz. I had wobbles until I boosted the primary head to 100hz. I can't up the second output past 75. The primary and the secondary are both running at 1280x1024.

I also had major wobbles on my old 17" monitor (G200 graphics card), and those only went completely away after I installed a UPS.

The second head wobbles, but that could be because the fans and power supply from my main case are literally 6" away from the monitor. I have to move it away, but right now the case is open - been swapping in cards lately. The wobbles go away at 60hz, but 60hz flickers to my eye. I've tried every in-between resolution. Next I have to try futzing with the more esoteric settings - back porch, pixel clock, etc.

Just my $0.02.




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Primary System: PIII-540 (450@4.5x120), Soyo 6BA+ III, 256MB PC100 ECC SDRAM, G400 MAX in multi-monitor mode. V2 SLI rig. Two Mitsubishi Diamond Pro 900u monitors, 3Com 3C905, SoundBlaster Live!, Altec Lansing AC5 spkrs, 2nd Parallel Port, WD AC41800 18GB HD, WD AC310100 10GB HD, Toshiba SD-M1212 6x DVD-ROM, HP 8100i CD-RW, Epson Stylus Pro, Sharp JX-9400 LJ-II compatible, OptiUPS PowerES 650, MS SideWinder Precision Pro USB joystick, Logitech 3-button mouse, Mitsumi keyboard, Win98 SE, Belkin OmniCube 4-port KVM

Secondary System: PII-266, Asus P2B BIOS 1008, 128MB PC100 ECC SDRAM, Millennium II, 3Com 3C590, ADSL Modem 640kbit down/90kbit up, 3Com 3C509, Mylex BT-930 SCSI card, Seagate 2GB Hawk, NEC 6x CD-ROM, Linux distro S.u.S.E. 6.1 (IP Masquerade works!)

Tertiary System: DFI G568IPC Intel 430HX chipset, P200MMX, 96MB of non-parity RAM, Millennium II, Intel Pro/100+ client NIC, SoundBlaster 16 MCD, Fujitsu 3.5GB HD, WD 1.2GB HD, Creative Dxr3 DVD decoder card, Hitachi GD-2500 6x DVD-ROM, Win98 SE

All specs subject to change.

[Pertti]

Keith,

You said you were working on two PC:s...

Any chance of you having two monitors side by side ?

If they are, put the case of one PC in between the monitors and the interference should stop.

Pertti

[Keith]

IceStorm, how did you crank your refresh up to 100hz? My settings only seem to go to 85hz. My dualhead is disabled (only using 1 monitor). Should this make any difference?

I do have quite a tangle of wires (one cheap powerbar which has a decent powerbar plugged into it) around the power outlet. I'll try plugging the monitor directly into the wall (or plug the decent powerbar directly into the wall). I'll also try using a ups (once I borrow one).

I should also mention that the monitor wobbles at startup (in dos). The wobble continues through the 'starting win98' screen and then stops once the desktop comes up @60hz.

Pertti, I don't have two monitors side by side. I'm using the same monitor for each computer (only 1 machine running at a time).

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-Keith

[Keith]

I've finally determined that my problem is not with the video card, but with the monitor. I brought my machine over to a friends place and tried it out. It worked perfectly.
I thought I would try using a ups at home, but that didn't work either. As it turns out, there must be some major interference in the corner where I have my computer set up. I moved the computer to another corner of the room and it worked quite a bit better (not quite 100%, but 98% or so).

I do have a 21" tv around 3feet away from the monitor, but I unplugged it and I'm still having the problem. Could the tv still be causing me problems? I have the tv coax cable running through the wall near my power outlet. Could this be causing me problems?

Is there anything you can purchase to shield your monitor from this problem?

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-Keith

[IceStorm]

Sorry, 100hz was for 1024x768. I can get up to 88hz on 1280x1024. When I wrote that, I was running my monitor at 1024x768 with a Half-Life window in the middle. I should have known better.

You have to go into the Monitor Setup panel, uncheck Use Simple Options, then adjust the refresh rate. You can also access the front porch/back porch/ pixel clock, etc. IF YOU DON'T KNOW WHAT YOU ARE DOING, DON'T TOUCH! Best thing to do is grab a copy of VidModes.doc, from a Linux X server distribution. That explains in detail how all those advanced options work together.

DOS almost always wobbles for me. Don't know exactly why. I'm pretty sure it's the sheer volume of equipment in the room. I have not locked in the refresh rates for DOS using the DOS Matrox drivers. At some point I'll have to do that.

If you're running through a monitor switchbox, make sure you've got high-grade cabling. I just upgraded my cables and boy, is there a difference! Get Tru Spec cables from Cables To Go. Worked miracles for me.

Just my $0.02

[Brian R.]

Keith - The wobble in dos is probably normal and is likely the result of degaussing circuitry. Many monitors automatically degauss when turned on or awakened from stand-by mode. It should not wobble in dos when you only reboot, only when the monitor comes out of standby or on power-up.

Brian