+5Hz problem

[thop]

hmm this one is rather strange. i run 1600x1200x80Hz (monitor default: 75Hz). recently i had GF3 in my system for a month, now the g400 is back in.

and with the g400 i experience a problem i have never seen before: when i watch .mpeg's or .avi's (no matter if windows or fullscreen, tried different players) there is a horizontal line running through the movie. it is especially visible with fast movement on the screen. it looks like the movie was chooped to two pieces and then put back together. hard to describe. now when i set the monitor to 75Hz the line dissapears

any ideas?

ps. i am using powerstrip for the custom refresh rate. now that i think of it i have been using matrox own utility before i put the GF3 in. so is this maybe a PS problem? wheres a board i can report to?

[Maggi]

vsync ...

I guess your movies are PAL based, ie. coded in 25fps and therefore you won't see any such teared frames in 75Hz, because it is an even multiple of 25 (each frames gets displayed exactly three times).

When having your CRT at 80Hz and VSync enabled, there is absolutely no way for your system to output all frames in sync and therefore you get a split screen on a regular basis.

For that reason I have my CRTs always running at 100Hz ...

Post back if you need more feedback.

[OasisPlaces]

It sounds like tearing (the video isn't waiting for vblanks)
since powestrip is overridding the driver, the driver might
be thinking it's in the wrong refresh, and handling the draws improperly.
Suggest you report this to both Matrox, and powerstrip..
who's fault is kinda shady..

[thop]

ah yes it is tearing i was missing the word. i'll try matrox own utility (in the driver tab), however powerstrip is a bit more convenient IMO. and most of my movies are actually 23,976fps, but even with other fps i have never seen this before.

[Maggi]

already tried to disable VSync ?

[thop]

where?
d3d vsync is forced off, so is openGL

[thop]

ok dumped powerstrip and have it running the matrox way now. problem is still there. played around with AGP settings, vsync etc - problem still there. set color to 16bit, problem fixed!

[3dfx]

Would you guys say that 120 hz is to much for a crt? it's just I have been running it at that for a ages and it looks great

[thop]

please dont hijack my thread 3dfx
but to answer your question: the more Hz the better i say.

[3dfx]

I'm soz thop I'm new but I'll learn

[OasisPlaces]

Originally posted by thop
ok dumped powerstrip and have it running the matrox way now. problem is still there. played around with AGP settings, vsync etc - problem still there. set color to 16bit, problem fixed!

i checked 75Hzx32bit again and the line is there, just a lot less noticeable (or i'm hallucinating or just stay too focused on the line that is supposed to be there). 75Hzx16bit the line is 100% gone!

Hmmmm... This is starting to sound like an overlay issue.
You might be in a mode where there's not enough bandwith
to support an overlay surface, so the drawing is being performed
manualy to the screen by the engine...which could have a tearing effect..

while this wont's fix you're problem..

You should ask the support at matrox to confirm where the overlay limites are (resolution/refresh/pixel) that might be it.

also try lower refresh rates in 32bit 60,65,70,75Hz..

there's a trick to check for overlay...Oh yeah.. you can check
but hitting prtscrn and pasting the image into paint, if you
have the overlay then the video windows is black (or some other color depending on the keying method), if not
then you have a frame of the video image..

[OasisPlaces]

Originally posted by 3dfx
Would you guys say that 120 hz is to much for a crt? it's just I have been running it at that for a ages and it looks great

For all intents.. depending on the lighting in your room, anything
over 75-85Hz just has more negative effects than positive..
They are..
More Stress on your monitor horizontal/vertical circuitry
Higher pixel frequencies just mean more noise on the picture
More of the memory bandwidth is being waster on just
drawing the screen, rather than drawing the graphics.

[thop]

ok i triple checked now with lower framerates (with scenes where the line is very visible) and the line does only appear with 80Hz and 32bit!

i was able to make a screenshot so i guess that means overlay was not the problem. will post this in the matrox forum.

[thop]

ok this seems to be a v-sync problem. at 75Hz i dont see the line. at 76Hz i see the line at the very bottom. with every Hz i increase the line goes up.

pon the overlay thing: i just read that at 1600x1200x32bit the 16MB g400 doesnt have enough ram left for overlay anyway.