I had the idea of installing a second pci video card (geforce fx5200) in my pc... my baseline, least common denominator platform is a 3gs, and I want to test my game's performance on roughly comparable hardware, as I develop it. Ideally I would like to hook up my main video card with dvi and the second with vga, and be able to easily toggle between the two.

Is this feasible? Do other people do this? Or would I be entering a world of headaches? My os is Windows 7.

I don't wish to hijack TysonL's thread, but I have a similar and related question - it seemed appropriate to put it here.

Is it possible to have an amd + nvidia card in the same system, and direct the bios to choose one over the other (init first display device - PCIE1/PCIE2). Obviously the two wouldn't be active enabled the same time.

just to add to this thread, I have just checked many posts relating to this on web sites... and the answers were No, or Yes!

It would appear that (under W7) no one seems to know whether
a: you can run two nvidia cards of different generations,
or b: you can run amd and nvidia at the same time.

There are several totally conflicting reports.

Personally, I was hoping to avoid buying a complete amd system just to test OpenGL functions! Although, it may acutally be worth while for several reasons (not least of which was an 8 core processor for half the price of an Intel equivalent).

Which reminds me... what is the AMD equivalent to a 560GTX?

Cheers

Personally, I was hoping to avoid buying a complete amd system just to test OpenGL functions! Although, it may acutally be worth while for several reasons (not least of which was an 8 core processor for half the price of an Intel equivalent).

Are you buying an AMD system for their opengl es support? If so I would advise against it. The last driver update broke it, at least for me, so after hours of pulling my hair out trying to figure out why my game stopped working I switched to ANGLE, which has worked very well so far.

[quote name='TysonJ' timestamp='1340384530' post='4951777']
I want to test my game's performance on roughly comparable hardware, as I develop it.

Then get an iPhone 3GS. There is no such thing as “comparable hardware”. Not even the iOS Simulator is comparable (its OpenGL ES 2 implementation is emulated in software, and provides no hardware support). There are numerous hardware differences that matter, including deferred tile-based rendering which eliminates overdraw (your GeForce card will not perform this) and a unified memory model which eliminates bus transfers to the graphics card.
iOS devices have a virtual memory system but no paging system.
Even threading is not the same.

Both Mac OS X and iOS adopt a more asynchronous approach to the execution of concurrent tasks than is traditionally found in thread-based systems and applications.

The point is that the only hardware that is like an iPhone 3GS is an iPhone 3GS. If you want to develop for one, get one.


L. Spiro
[/quote]

I'm aware that they are quite different, but they are not so different that optimizing one will harm the other. What I meant by "comparable" is that if I can get one to run at 60hz, the other probably will as well, or at least be most of the way there. Does that sound about right? Really I want to find every excuse possible to stay in my cozy pc development environment

If you have the available port and get an additional monitor, it works perfectly fine to use two different GPUs simultaneously on Windows 7. Just connect them both, install both drivers, and they will work side by side as a normal multi-monitor environment. I currently have one NVidia and one AMD running.

If you get a very old and a newer card from the same vendor there might be driver collisions.. I haven't tried that...

If you want only one monitor and two graphics cards and switch between them that should also be possible, just put the DVI cable into one card and the VGA cable into the other, and let Windows think it's two different monitors. Then switch between which card/input you use with the monitors control panel and the monitor input settings.

EDIT: The monitor/input that you use for OpenGL must be set to the 'primary monitor' in the Windows monitors control panel. So to switch between the cards for OpenGL, switch which one is the primary monitor.

What I meant by "comparable" is that if I can get one to run at 60hz, the other probably will as well, or at least be most of the way there. Does that sound about right?

No.

The PowerVR chipset on the apple stuff has a completely different architecture than most pc gfx adapters. You will have to optimise different aspects of your renderer to get the best performance out of it.

Thanks Erik, that's what I wanted to know.

I basically want to be able to test opengl on both video cards without physically swapping them in and out of the system, not run a dual monitor setup.