More RAM or CUDA?

Spectralis wrote on 11/2/2010, 7:33 AM
I'm using Vegas Pro 10 and After Effects CS5. I've got a 6 core AMD PC with Win 7 64-bit and 8GB RAM. I'm totally confused about whether to upgrade my RAM to 16GB or buy a compatible CUDA card to power plugins in Vegas and AE.

1. Will Vegas and AE benefit much by increasing RAM from 8GB to 16GB?

2. Do compatible CUDA cards make much difference to performance?

3. Which CUDA cards work with Vegas 10 and AE CS5?

I've tried searching for info but what I found claimed that the increase from 8GB to 16GB RAM wasn't that significant with AE. I'm not sure if this is the case with Vegas.
As for using CUDA cards I couldn't make head nor tail of what cards work and what the performance gains are. Anyone have experience with this?

Comments

Xander wrote on 11/2/2010, 7:40 AM
I have a Quadro FX 4800, but don't see as much benefit from it's Cuda abilities as I would expect. It is, however, more than powerful enough to drive both my 30" HP LCD and my 23" Asus 3D LCD monitors.

I have 24 GB of RAM installed and AE CS5 will ramp up to using 21GB every time I render. I definitely notice more benefit from the increased RAM.
Spectralis wrote on 11/2/2010, 8:39 AM
Thanks for the reply. I think I'll order more RAM.

It seems a bit unclear exactly what CUDA actually brings to Vegas and AE. I've checked Adobe, Sony and NVidia websites but can't find a clear explanation about what to expect when using CUDA. I think it actually speeds up Premier CS5 while just improving plugin performance in Vegas and AE.
TheHappyFriar wrote on 11/2/2010, 9:42 AM
The Nvidia cards help Vegas render AVC. It won't help with anything else unless the specific plugin is designed for it. In most cases, eigther an ATI or Nvidia will work.

But unless you render to that specific format, it's a waste of $$ to buy a nice CUDA card for Vegas.
richard-amirault wrote on 11/2/2010, 12:12 PM
I thought it was AVCHD *preview". not render, that took advantage of Nvidia cards.
TheHappyFriar wrote on 11/2/2010, 12:21 PM
Just checked, the website says AVC Rendering..

I'll fix my post above.
Spectralis wrote on 11/2/2010, 2:16 PM
Thanks for clearing that up. I find it confusing because some audio plugins can run on CUDA I think. There seem to be a variety of ways of using the extra power depending on the product.
John_Cline wrote on 11/2/2010, 2:40 PM
I have some relatively inexpensive (~$140) nVidia 450GTS video cards and when rendering 1920x1080 AVC from Cineform intermediates using CUDA I am consistently seeing a 30% increase in render speed over CPU only.
DavidMcKnight wrote on 11/2/2010, 3:00 PM
John - is this on your Intel QX6700 Quad-Core, 3.2Ghz OC machine (from yer specs)?

I have, I believe, the same or similar GTS card and it's a tad slower than CPU only on an i7 950 stock.

It would be nice to find some comparisons between CUDA and CPU to find out the various sweet spots.
Spectralis wrote on 11/3/2010, 8:31 AM
30% is a very significant improvement. I'll check that card out. I wonder if there would be even more of an improvement with a higher spec card? It all seems a bit mystical atm. A kind of word of mouth approach. I can't find any CUDA comparisons that look at rendering performance so it's hard figuring out which cards work and what to buy. Will spending £50 more for a card make much of a difference to rendering? I suppose the faster the cards DRAM the better performance. You'd think NVidia and ATi would be falling over themselves to hype their products to the home video market.
Stringer wrote on 11/3/2010, 10:43 AM
Does rendering to AVC automatically use the GPU, or are there settings that need to be tweaked ?
DavidMcKnight wrote on 11/3/2010, 11:17 AM
You can choose to use the GPU or the CPU when you render.
John_Cline wrote on 11/3/2010, 12:48 PM
David, yes, the 30% increase is on my aging QX6700. As you pointed out, the percentage increase in AVC render speed will be less if you have already have a very fast i7 machine. In fact, enabling GPU rendering could potentially be slower on an already fast i7. CUDA is not some magic technology and not everyone that buys the same nVidia card I did will automatically see a 30% increase in AVC render speed. The disclaimer, "your mileage may vary" is exceptionally appropriate in this case.
Laurence wrote on 11/3/2010, 3:36 PM
CUDA makes a pretty big difference in my particular laptop which has pretty capable nVidia graphics built into a Core2Duo. Pretty cool for me at least.
srode wrote on 11/3/2010, 5:12 PM
Ram over 8gb won't help speed up anything in Vegas - but it will let you prerender larger sections to ram. That's based on my experience anyway.