GTX 670 Rendering Slower Than CPU

NovaWar[LAGTV] wrote on 9/18/2012, 10:57 AM
I've been fighting with this for a while now and since Sony user support is literally non existent (which is disgusting given the nature of this product), I'm hoping one of you might have an answer.

I render in AVCHD with a custom profile just for bitrate changes and such. I have GPU rendering enabled in the global options and I've even tried forcing the GPU rendering option. It's definitely working as there is a speed difference, the problem is that it's slower than the CPU alone.

At first I just thought that maybe the GPU was too new, but I've used FREE encoding software and it uses the card beautifully.

Have any of you run into this and do you have any suggestions?

Thanks

Comments

Tim20 wrote on 9/18/2012, 11:07 AM
Yes I have a GTX570 2gb and some things render slower than an i7 with 8 threads running. Dynamic ram preview setting of 200 mb or less tends to help regardless.

Gotta read Sony's fine print at the bottom of the wonderful marketing pitch for GPU accl: Results may vary depending on blah,blah, blah
NovaWar[LAGTV] wrote on 9/18/2012, 10:52 PM
That just doesn't make any sense at all. My 670 should obliterate my cpu in rendering speed lol. I mean, Freemake (a video converter) uses Cuda and when it's enabled it is insanely fast versus the cpu.

If a free program handles CUDA better than Sony's $800 "professional" software then I might just jump ship the moment an alternative crops up.
Zeitgeist wrote on 9/19/2012, 1:51 AM
Render speed is also based on what plugs are being used & if they are 64bit &/or gpu accelerated. Even some of the sony plugs that come with Vegas are not 64 bit.
Tim20 wrote on 9/19/2012, 6:19 AM
About the only things out there that are really optimized for CUDA are Adobe Premeire and After Effects. But the user interface is hard to get used to.
farss wrote on 9/19/2012, 7:44 AM
It's not just that, the underlying H.264 codec is a complex beast that has tradeoffs between quality and speed. I would expect / hope that the implemnation that ships with a NLE is more optimised for quality than speed.
If speed is what you want and it's only a simple transcode to a different bitrate a 3rd party solution is probably a better way to go. I'm not 100% certain of the intracies of this but I think it's even possible to squish a H.264 stream into a smaller bandwidth wihtout even re-encoding.

Bob.