how do 2 GPU's behave?

[sharky]

hi guys!

how is it like in windows if i have 2 GPU'S (identical) NOT in sli mode? if i open a game for example, can i choose what gpu to use? or even better, can i have both gpu's outputting the very same thing at different resolutions? what i want is to use the iz3d on one gpu and the projectors on the other one. would it work?

thnx

igor

[sharky]

woot? still nobody? isnt there anybody with two gpus in here?

[UndeadD3vi1]

I don't think you can do this, at least not the way you want to.

What game is it? I.e. if it was UT3 you could run a local server and run two copys of UT3, one that you actually play while the other connects as a spectator on your player. I think thats the closest you can get to what you want to do.

[Likay]

I have both a 7900 and an 8800 in the same comp. They work great together (both enabled) using the 169.21 drivers but i still deactivate the one i'm not using for the moment (and rebooting). Otherwise i sometimes have to turn on the projectors a short time just to see what i'm doing/alter displaysettings and that's not good. Later displaydrivers doesn't support the either the 7900 or nvidiastereo too well.
I'm not sure about using two cards if they're the same but i still think you can deactivate one of them. Unfortunately this requires reboot as well....
Not too much of an answer but maybe you get some creative ideas.

[sharky]

thanks for your answers guys.. rebooting is definetly not an option.. likay what do you mean that you have to power on the projectors to see what oyu do? aren't all 4 displays enabled? so that the screen 3 is a clone of screen 1 and screen 4 is a clone of screen 2?

do you have a chance to test it please? i hate to spend 150 euro on a gpu if it doesnt work..

[sharky]

or even better, is it possible to buy a cheat (30$ ) gpu, having the expensive one do th emaths, and use the cheap one ONLY for video output? i mean to output what the expensive one has rendered.. the guys at nvidia aren't responding..

[cybereality]

or even better, is it possible to buy a cheat (30$ ) gpu, having the expensive one do th emaths, and use the cheap one ONLY for video output? i mean to output what the expensive one has rendered.. the guys at nvidia aren't responding..

I don't really think that is possible, or at least I haven't heard of that being done. Can you explain exactly what it is you are trying to accomplish here, maybe there is a solution we are missing? I get that you want some sort of dual output but can you be more specific. Do you want the iz3d to be in 3d and the projector in 2D, at different resolutions?

[Likay]

Sorry for late answer. This slipped past me. As you know i also use two cards but different ones. Having both cards installed and enabled is not always giving desired results in choice of displays using iz3d/old school nvidia. Therefore i disable the card i'm not using for the moment.
Another "problem" specific for this rig is that i use vga-to-tv converters between the comp and projectors (alt iz3d when used in 2d-mode). These tells the driver that a lot of refreshrates that iz3d monitor doesn't support is valid. If the drivers choose some of these refreshes when switching card then i have to turn on at least one of the beamers to see what i'm doing.
So the problem is related to the supported refreshes of the vga-boxes + iz3d + unexpected behaviours of the displaydrivers.
It would be great being able to run both cards at the same time the way i want, but it simply doesn't. It's not too often nowadays i switch between the 7900 and 8800 though.

[sharky]

hi guys thnx for the answers..

i try to explain what i am trying to do more precisely.

i have an iz3d (2 dvi cables) and 2 projectors (1 vga cable each)

what i want to do is switch between them (switch between iz3d and projectors) without having to reboot the pc. right now it is a mess. i tried cable splitters dvi to dvi+vga but they dont work because the gpu can output ONLY dvi OR vga. to change from one to another i have to unplug the one i dont want and restart the pc, because the gpu autodetects what is connected. since dvi is digital and vga is analog i can not use 2 outputs to power 4 rigs. therefore i have to find the cheapest solution possible to arm my pc with 2 more outputs.

i have no idea how it is inside windows when you have 2 gpus not in sli. i mean how the system is going to manage them. i was thinking that maybe you specify a primary and a secondary one, and in you desktop properties you see 4 desktops. set the first two to extended, and the other two as clone of the first two. that would work for me. but so far i didnt find anything that works.and that pisses me off because i dont think i am the first person worldwide who needs 4 outputs on a pc, cant be so difficult / expensive to do all this.

argh..

[sharky]

Sorry for late answer. This slipped past me. As you know i also use two cards but different ones. Having both cards installed and enabled is not always giving desired results in choice of displays using iz3d/old school nvidia. Therefore i disable the card i'm not using for the moment.
Another "problem" specific for this rig is that i use vga-to-tv converters between the comp and projectors (alt iz3d when used in 2d-mode). These tells the driver that a lot of refreshrates that iz3d monitor doesn't support is valid. If the drivers choose some of these refreshes when switching card then i have to turn on at least one of the beamers to see what i'm doing.
So the problem is related to the supported refreshes of the vga-boxes + iz3d + unexpected behaviours of the displaydrivers.
It would be great being able to run both cards at the same time the way i want, but it simply doesn't. It's not too often nowadays i switch between the 7900 and 8800 though.

sorry i dont get one thing.. why dont you update your drivers and use iz3d projection drivers?

[sharky]

according to this article it is possibel


http://en.wikipedia.org/wiki/Multi-monitor" onclick="window.open(this.href);return false;

[Likay]

The reason why i keep the 7900 is that i occasionally play older games. The last relatively good working config for old school nvidia seems to be the 169.21+162.50. This driver also supports both cards.
I don't switch and reboot too often so i bare with it.
If you switch cables live you need to reboot the gpu and probably the displaydrivers to reread the new monitor (edid info and load proper displayconfigs). I don't know if this is possible without reboot anyway... Have you tried looking for some special nvidia tools (stoopid question, i know you have).
Switching cables live is nothing i recommend, at least not vga-cables. Have by experience fried one output of a 6800 ultra. I switched it manually which might not have been enough fast to avoid damage. Now i turn of power to one of the vga-boxes, then switch cable from that (when switching between the iz3d as 2d-monitor and the projector rig). Edid is the same since the boxes provides them to the pc. On the other hand i can get refreshrateissues with the iz3d if i'm not watchful.

How about if you do have two cards of the same brand and family, same drivers and configed as four outputs? Then you should only have to change the primary displays (1 and 2) which should be used by the iz3d-driver as default. Since i have two cards the displaydrivers for some reson behaves fishy (unstable) but i have got it working with both cards installed. The game is played using only one card though.

[sharky]

tomorrow my brother goes away for the weekend so i can "borrow" his 8800 and test it out.

i found a software (ultramon) that can make a whole load of printscreen of the first gpu and then output it to the secodn one. so basically the first one does the calc, the second one does the output. but its a very slow process and the developer said that it doesnt work as it should on all systems. i think illt ry it tomorrow...

lets see what i come up with..