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IMI
09-19-2008, 05:56 AM
If it's true that an image file texture uses 10x the image file size in in RAM, in Layout when rendering, i.e., an image with a file size of 1 KB will use 1 MB of RAM at render time, does the same go for video card RAM?
And, what happens if you have more texture in your display than your video card has RAM? Is it safe to say that as long as you're seeing textures in your viewport, you still have enough RAM? Or does your system RAM or page file take over in that case?
Also, are you using the same amount of VRAM for all your viewports in textured mode as you would for one only? Meaning, if I have textures enabled in the perspective viewport, but not in any others, does the VRAM usage increase as I enable it in other viewports, or does it stay the same?
Does changing the texture display resolution affect how much VRAM is being used, or only affect the OpenGL display speed?

And, how can you tell how much VRAM your card is using, anyway? Is there a utility that can read how much of the RAM in your graphics card is being used, cached, or free? Does LW have a way of displaying that?

Thanks if anyone knows. :)

Lightwolf
09-19-2008, 06:18 AM
If it's true that an image file texture uses 10x the image file size in in RAM, in Layout when rendering, i.e., an image with a file size of 1 KB will use 1 MB of RAM at render time, does the same go for video card RAM?
Yes. Well, except for non-8-bit per channel images, afaik LW only uploads them as 8-bit images to the openGL hardware.
The file size is only smaller if your image file is using an image format that compresses btw.

And, what happens if you have more texture in your display than your video card has RAM? Is it safe to say that as long as you're seeing textures in your viewport, you still have enough RAM? Or does your system RAM or page file take over in that case?
System RAM. This is a technology that AGP was initially designed for.


Also, are you using the same amount of VRAM for all your viewports in textured mode as you would for one only?
Yes. The images only get uploaded once.

Does changing the texture display resolution affect how much VRAM is being used, or only affect the OpenGL display speed?
Both.

And, how can you tell how much VRAM your card is using, anyway? Is there a utility that can read how much of the RAM in your graphics card is being used, cached, or free?
I've seen a free one around, but I'd need to do a little googling to find it.

Geometry uses VRAM as well (which technically isn't VRAM - but that's another topic) - especially if you use VBOs.

Cheers,
Mike

IMI
09-19-2008, 06:25 AM
Thank you for the answers, Mike. :)
I've searched for some sort of utility. There are all kinds of graphics card utilities that can display/adjust temp, fan speed, core, shader and memory clock speed, but I haven't found one that shows VRAM usage.
At least, Riva Tuner and the EVGA Precision tool don't.

Lightwolf
09-19-2008, 06:31 AM
I've searched for some sort of utility.
PerfHUD from nVidia does, but only for Direct3D apps. And it certainly is more of a developer tool than anything else.

Maybe I'll stumble across the one that I saw ages ago.

Cheers,
Mike

IMI
09-19-2008, 06:53 AM
If you do, that would be cool, but I think they're few and far between. I was doing some major searching for such a thing last week, but came up with nothing but the type of video card apps I mentioned. I guess VRAM is shy or something, and doesn't like being exposed. ;)
At least now I know how to calculate it if I think there will be a problem. I have a huge scene I want to do, and was trying to figure how much I need to resize/compress my image files. I have 8 gigs of sys RAM and 640 MB of VRAM, but I don't want to push it all to its limits anyway.
Thanks again.