OT: What is advantage of more GPU RAM?

Rich Parry wrote on 4/5/2012, 10:27 PM

The new nVidia GeForce GTX 680 (1,536 CUDA cores) video card comes with 2GB RAM. A card with 4GB should be available soon.

I know what more RAM means for a CPU (more apps can run, less memory swapping, etc.), but I don’t know what more RAM on a video card means. As a VP11 user, is there a reason to get a card with more RAM. This is not a matter of trying to save money, it is a matter understanding if more GPU RAM is useful to VP11 and what does it get me.

Thanks,
Rich

Comments

farss wrote on 4/5/2012, 10:42 PM

"This is not a matter of trying to save money, it is a matter understanding if more GPU RAM is useful to VP11 and what does it get me."

What I read on the web agrees with my own thoughts. For Vegas more VRAM will make no difference.
The only use for excessive amounts of it seems to be for holding texture maps used in gaming. Obviously the OpenCL calcs that Vegas is asking the GPU to do must have their data also stored on the graphics card so faster VRAM is probably going to be of some advantage.

At best I'm only taking a not very educated guess and (again) it would be rewarding to hear from the people who wrote the code.

Bob.

riredale wrote on 4/6/2012, 11:14 AM

Based on my own experience, not much ram is actually needed when it comes to video rendering. Perhaps as Bob says the extra ram in video cards can be put to good use for texture mapping and building a believable 3D environment based on limited information, but if so I don't know if Vegas is able to use that video card ram for its alternative purposes.

I have not experimented with the latest versions of Vegas but I do know that V7 requires very little motherboard ram to render complex projects. I never see V7 consume more than ~250MB based on real-time feedback from RamPage. When I upped my system ram from 1GB to 2GB years ago I did not see any decrease in render time and RamPage showed that extra ram just sitting there, converting electricity into heat. I even shut down my system's swapfile--no effect.

The only time I get close to maxing out my system ram is when I run multiple instances of Vegas along with all the other day-to-day programs my system runs main parallel (web surfing, email, web server, word processing, ReplayAV stream recorder, LogMeIn, Avast antivirus). Oh, I should also mention that DeShaker can throw and additional 200MB load into the mix.

I'm not trying to sound like a Luddite here ("640k is all the ram they'll ever need") but do later versions of Vegas tap into 8 or even 16GB of additional ram loaded into a 64-bit system? What on earth would Vegas load it up with? And do folks with that much ram still use a swap file? If so, why?

Rich Parry wrote on 4/6/2012, 11:54 AM

Thanks for reply. While we don't have a definitive answer, I suspect extra GPU RAM doesn't mean much in the Vegas rendering world. Probably more important to gamers.

Regarding your comment about CPU RAM not being used on your system, I can't argue with your findings, but in these days of loading 10-20 HD clips on a timeline each 100MB or more, I would think that CPU RAM is extremely important.

Thanks again,
Rich

riredale wrote on 4/7/2012, 7:19 PM

Makes no difference, at least in V7. I've done HD projects 3 hours in length on a 32-bit system with 1GB of ram, no issues at all. Having a project with 100GB of HD video does not mean that 100GB of ram is needed, even if all of the clips are on the timeline at once.

What I don't know is whether Vegas (or more accurately, later versions of Vegas) actually decodes AVCHD clips that are played and then it leaves them in ram, so that a second decoding is not needed if the user decides to go to that part of the timeline again. I doubt it, because it could become a logistical nightmare, but maybe Vegas does that.

TheHappyFriar wrote on 4/7/2012, 7:23 PM

It's texture memory and I'm betting OpenCL doesn't use it. If you have any OpenGL or DirectX apps those will use the memory.