Poor windows performance when alt-tab a game?

Lyon85 · 13 May 2007 at 09:21

On my old system (6800GS, AMD Athlon 64 3200+, 2Gb Ram) I used to be able to alt-tab games and use windows with very little performance loss. On my new system, when I alt tab I get horrible jerky performance. It has nothing to do with how quickly apps open, but say I'm in firefox and I use the scroll bar down a page, I get what looks like 2fps.

Does anyone else get this? Is there any software tweaks I can do to get similar performance to my old rig?

Thanks in advance

Mansize_tissue · 13 May 2007 at 09:25

If the game is still open, chances are it has been given a higher priority over Firefox. You could try increased the priority of Firefox in Taskmanager and see if it makes a difference.

Lyon85 · 13 May 2007 at 09:32

That probabaly makes sense, but I'm more interested in an explanation as to why it does it in the first place, when my previous inferior machine had no trouble at all.

I'l give it a try anyway, thanks.

FrannoBaz · 13 May 2007 at 11:25

Do you have Vista?

Lyon85 · 13 May 2007 at 12:07

Nope, WinXP SP2 (32bit). Same as my old rig.

Jokester · 13 May 2007 at 12:14

Are you now using an ATI card now?

I've had similar problems, tabbing in or out of a game would result in terrible performance for a few seconds. With Nvidia cards it works without problem, so it seems like a driver issue.

Jokester

Jaffa_Cake · 13 May 2007 at 12:17

Can also depend what game it is.

Lyon85 · 13 May 2007 at 12:27

Yeah I'm on ATI X1900 XT, C2D E6300 @ 3Ghz, 2gb RAM (all in sig).

So far it happens with every game I have tested.

Jokester, when you say a few seconds, does it return to normal performance after that period?

My alt-tab is instant, I can get into Windows in about a second, but the performance remains consistantly low while I am in windows.

Jokester · 13 May 2007 at 13:06

Nah, mine would grind to a halt (3-4fps) for a couple of seconds after Alt-Tabbing (the change as you would say would be instant) then return to normal.

Jokester

Corasik · 13 May 2007 at 13:43

I've notice a 'similar' issued with ATI cards, Sometimes I play Wow/Everquest in 'windowed' mode, for quick access to a web browers.

With my Nvidia based PC thats no problem at all, but with the ATI computer, if I bring the mouse anywhere near the start bar, the computer just grinds to a halt. Same if I am fullscreen and alt tab.

Seems ATi cards demand more from the CPU than Nvidia, and are less suited for 'background' tasks.

Dureth · 13 May 2007 at 14:03

Corasik said:
Seems ATi cards demand more from the CPU than Nvidia, and are less suited for 'background' tasks.

Not exactly true. Whats happening is because in XP the desktop is a 2D rendered buffer image when switching from 3D to 2D rendering there is a huge performance halt while the driver/GPU changes states. Now nVidia drivers handle this change better than ATI's but that still doesn't explain why the OP is experiencing long term slowdown as it should just last a second or two.

This problem should be sorted completely with Vista and DX10 as the driver and DX10 are both built to enable smooth changes of priority between different tasks. As the Vista desktop is also rendered in 3D this also reduces the performance hit for changing tasks.

I'd try updating or re-installing your graphics drivers. Otherwise I can't think why the slowdown is present for more than a few seconds.

Netvyper · 13 May 2007 at 14:12

This is one big advantage of vista over XP, because of the new buffered display mode stuff. Its a feature I make extensive use of

Lyon85 · 13 May 2007 at 14:53

I thought I might be better off showing you guys. I've just realised though that it actually isn't all games. I just alt-tabbed Splinter Cell Double Agent and it was fine from the moment it minimised.

Most games though, like BF2 do it:
http://www.youtube.com/watch?v=78sy9uOHIFc

The Halk · 13 May 2007 at 14:57

Lyon85 said:
I thought I might be better off showing you guys. I've just realised though that it actually isn't all games. I just alt-tabbed Splinter Cell Double Agent and it was fine from the moment it minimised.

Most games though, like BF2 do it:
http://www.youtube.com/watch?v=78sy9uOHIFc

To be honest I'd worry more about your aim than anything else. You wasted loads of ammo there and hit nothing!

Lyon85 · 13 May 2007 at 14:59

The Halk said:
To be honest I'd worry more about your aim than anything else. You wasted loads of ammo there and hit nothing!

Left hand!

Jokester · 13 May 2007 at 15:00

That reminds me of Windows performance when you've using the default VGA drivers when you first do an install. Did this system previously have a Nvidia card in it, or was it a clean install with only ATI drivers installed?

Jokester

Lyon85 · 13 May 2007 at 15:02

Jokester said:
That reminds me of Windows performance when you've using the default VGA drivers when you first do an install. Did this system previously have a Nvidia card in it, or was it a clean install with only ATI drivers installed?

Jokester

Yeah it does look like that, I should have used that comparison. This ATI is the only card that has ever touched this mobo though.

The Halk · 13 May 2007 at 15:04

Lyon85 said:
Yeah it does look like that, I should have used that comparison. This ATI is the only card that has ever touched this mobo though.

Does no harm to uninstall the drivers, boot to safe mode and driverclean them away.

When you get back to normal windows reinstall them.

Probably won't solve it, but it's quick and easy.

Lyon85 · 13 May 2007 at 17:35

The Halk said:
Does no harm to uninstall the drivers, boot to safe mode and driverclean them away.

When you get back to normal windows reinstall them.

Probably won't solve it, but it's quick and easy.

I probably should anyway, I haven't used driverclean on this install of XP yet.

I guess it's no huge problem, I'm getting "a good few frames" in game