Dual monitor fps very low

[MidNiteMysT]

First, my video card
SAPPHIRE 100134L Radeon X1800XT 512MB GDDR3 PCI Express x16 Video Card - Retail

I know it can handle two games at once. If I have both games on one screen, its nice and smooth, but If I drag one game window to the other screen, the fps on both screens is unbareable. It will be about 1fps and I cant play at all.
And no, i dont wanna play two games at once but I like to be able to talk in one game while im in another.

Is there a fix for this? I know my video card can handle it because when they are on the same screen, both windows work flawlessly.

Any help?

 

[dug777]

I don't think most cards will drive 2 3d heads at the same time will they?

Your graphics card has to have 'focus' on one screen for hardware acceleration (at least, under XP)...

I think

Anyway, i've never managed to get two 3D apps fullscreened on my duallies that i'm aware...

 

[nullpointerus]

For nVidia cards, there's some setting for multi-monitor 3D acceleration, so there's probably a similar setting buried in CCC somewhere. Maybe it's in the game profiles section.

 

[MidNiteMysT]

I tried looking everwhere in CCC but I could not find a option for 3d acceleration on 2 monitors. If I change the game to the other screen, it will play there fine too but lets say i had two games on one screen and one is in a window, even if just the border of that window is a tiny bit on the other screen, fps drops way down.

Has anyone ever done this before?

 

[MidNiteMysT]

Anyone have any more info regarding this?

 

[nullpointerus]

From your description, multi-monitor 3D acceleration appears to be on by default in ATI's drivers, and it appears to be working fine. I think some slowdown is to be expected when a 3D window is partly on both monitors, unless you are playing the game fullscreen.

 

[jasonja]

Originally posted by: MidNiteMysT
Anyone have any more info regarding this?

I assume you are running this on WinXP because this generally isn't a problem on Vista. On WinXP the two heads are treated as two completely seperate video cards to the OS. So while they technically do share the same video memory and engine the OS treats them seperately as it would if they were two completely seperate video cards (1 AGP and 1 PCI for example). So when you start a game it by default will run in the primary then when you drag it to the other monitor your actually adding a bunch of extra overhead to the rendering. In order to do this the DirectX runtime renders everything to a backbuffer on the primary adapter then it blts it out to system memory, then it does a system to video blt on the secondary adapter and then it appear s on the screen. These extra steps of blting from adapter 1 to system and sytem to adapter 2 is what is killing your performance. Vista no longer does this and it understands that it's all the same adapter so the performance drop doesn't occur there.

The only way around this on XP is if the app will let you pick which adapter to use. Most of the more simple DX9 sample apps for example will let you pick the device and you'll see in those cases that there are two devices (one for each monitor). When you force the app to use the 2nd adapter then it's fast on the 2nd monitor (and would then be slow if you dragged it over to the primary monitor). If you game isn't multiadapter aware then I don't think there is anyway around this.

 

[MidNiteMysT]

Sorry for the very late reply.

Thank you for the detailed explanation.

And to nullpointerus. the fps degrades to almost 40% when i have a 3d game up in both screens, even if its just the border of the window without even any video running on the other screen.

I also noticed that when i play the game, and my instant message program is on, when someone signs on, a little window will pop up in the bottom left corner of my game screen and then when it fades away, my graphics will be hindered almost 50% until it fades away completely which is very weird since its on the same screen and its a very minor graphic.

 

[MidNiteMysT]

UPDATE!

ATI sucks and i hate them forever

Im using a geforce card now and theres no slowing down AT ALL. It doesnt suffer from any of the symptoms the ati one did. So im not sure what you were talking about jason but i dont have the problem anymore. And the funny part is, this geforce card is much worse and it doesnt have that stupid problem. No more ati for me