video card refresh rate out of spec? 1

[dementg]

I have a Hercules 3D Prophet II MX card, which uses the GeForce 2 MX graphics chip. I've noticed for a long time that it seems to produce an incorrect refresh rate. I'm using windows 2000 display properties to set the refresh rate.

When I set 85Hz, the monitor reports 90Hz.
When I set 75Hz, the monitor reports 80Hz.
When I set 60Hz, the monitor reports 64Hz.

When the system boots in text mode, it starts at 64Hz and later switches to 74Hz (still in text mode). I'm sure those are supposed to be 60Hz and 70Hz.

I have hooked other computers up to the monitor and validated that the monitor's refresh reading is accurate. The only system that produces these awkward refresh rates is the one with the Hercules card in it. I haven't overclocked the video card. Doing the math, it looks like refresh is running 6% too fast.

It can be annoying when I'm trying to run a game at 1600x1200, because my system rightfully believes it can run at 1600x1200 @ 85Hz and attempts to do so. Unfortunately the video card puts out 90Hz and the screen goes blank. The cumbersome way around that is to manually force it to run at "75Hz", but it annoys me to pay for a monitor that can do 85Hz at that resolution and then have to sidestep around it.

As far as I know, this video card has always been doing this. Is there some possible reason for this problem that I can fix? Is it a defect, or do some video cards just not adhere to standards very well? This seems like a very weird problem to me. Thanks, any comments appreciated!

 

[dakota81]

Well my observation is, do you want to put much time & effort into an older, relatively low performance video card?

I can't offer any further advice, I would think this is an isolated incident with the video card myself, just speculating.

 

[dementg]

I'm sure I'll upgrade eventually, but I'll continue to use the card for years in a secondary or third system. If it really bothers me, I guess it wouldn't cost much to replace it, and I'm at a loss to come up with any way to fix it.

This card had somewhat faster memory than other similar cards (183MHz vs. 166MHz), so I was curious if they went about that in some sloppy way that somehow caused the refresh to go out of spec. I tried enabling the overclocking controls in the driver, but as expected, underclocking the card to 166MHz doesn't affect the refresh rate.

It appears there's nothing I can do about it, but I'm curious how something like this happens. I wonder if all cards of this model didn't refresh at the correct rate, but I suppose its just an unusual random defect.

 

[SYAR2003]

If you install some utility like rivatuner
you can set the refresh rate to use for all resolutions.
In your case it will result in doing some testing what to set for each resolution .E.g 640x480 60hz maybe must be set to 55hz and so on .
But when this is set for all resolutions the
vga adapter will use that for all.
Rivatuner can be dowloaded from

http://www.guru3d.com

 

[dementg]

I finally downloaded rivatuner. I set up an override for the refresh, but for some reason I couldn't get it to have an effect. Maybe I'll figure it out eventually. In any case, it looks like an interesting program and I'm sure I'll be playing around with it some more. Thanks for your help.