Will Radeon 6970 Improve Render Time vs. Radeon 7850

[Mike Kerr]

No, I am using Sony Vegas 13 Platinum.

Perhaps I’m too noob or don’t understand something. A lot of what has been posted in this thread is above my head. I found my way here through google several days ago trying to find out ways to improve render times in Vegas for YouTube, which consensus seems to indicate we should use the Main Concept AVC codec. I have a newer Radeon card not supported by MC, and (IMO) a fairly decent CPU. Unfortunately there does not seem to be any insightful discussion anywhere else on this topic.

I just want to know if putting in an older series card that is supported will render faster using GPU than right what I’m using now (a newer card and CPU).

So far I understand half of what people have graciously taken their time to respond with, and a recommendation to upgrade my CPU (which would require a motherboard upgrade and re-installing my entire system). If what I’m trying to ask is more complicated than a yes/no, or if I’m asking the wrong question, then just let me know and I’ll move along.

[John Rofrano]

[Mike Kerr] “I just want to know if putting in an older series card that is supported will render faster using GPU than right what I’m using now (a newer card and CPU).”

I believe the answer is YES. The MainConcept AVC encoder gave me a 3.6x improvement in performance with my AMD Radeon HD 5870 GPU. Here is a thread with all the details:

“New” graphics card

I assume an AMD Radeon HD 6xxx series card would do even better. The 6000 series is the last one supported my MainConcept AVC.

~jr

http://www.johnrofrano.com
http://www.vasst.com

[Dave Haynie]

Ok, first, let’s deal with the details:

* MainConcept AVC will probably deliver a better result than Sony AVC at lower bitrates. MainConcept can also do VBR encoding, Sony can’t. So there are some advantages to MainConcept. At higher bitrates, there’s not likely much difference.

* MainConcept has very good GPU acceleration that they won’t enable if your GPU basically isn’t on their internal list. There’s no good reason for that aside from pressuring Sony to upgrade, but since they stopped doing upgrades (MainConcept has been a division of several different companies), that’s what we’re stuck with. GPU rendered AVC isn’t quite as high quality as CPU rendered AVC, due to the differences in algorithm. Maybe some day, but probably not from MainConcept. The HD6970 — my GPU, BTW — is the fastest card for MainConcept support, far as I know.

*All newer GPUs support OpenCL just dandy — the MainConcept problem is something different (they reject GPUs hard coded in their driver, kind of doing an end run around the very concept of OpenCL).

So, OpenCL is also used by Vegas itself. Some plug-ins use it, the compositing engine uses it for some work, etc. Basically, you refer to “preview” acceleration, but truthfully, anything that speeds up preview using the GPU can also speed up any render to any CODEC.

So the real questions to answer: [a] will the HD6970 speed up your MainConcept AVC renders, and [b] will the HD6970 at least not slow down your system in any other way, in order to make [a] worthwhile.

Ok, so as far as speeding up your system, yes, it will. My old system was based on an AMD 1090T processor, a 6-way “Phenom II” processor. There are a few architectural advantages in Phenom over the Piledriver architecture in your CPU, the idea of two integer CPUs sharing one FPU and L2 caches, but the extra cores and clock speed means your chip should edge out my old one, but probably not enough to change basic system behavior.

Given that, the HD6970 was a dramatic speed improvement for MainConcept rendering on my old system, so probably on yours, too. I didn’t find that specific benchmark, but it was a solid increase. In fact, I bought both the HD6970 and the price-parity nVidia, GTX580 maybe, and ran the Sony benchmark and other tests. The nVidia went back. And Vegas 12 improved the rendering performance, mostly due to Vegas itself using the GPU, not just the MainConcept plug-in. That benchmark is around somewhere.

Here’s a thread with the results on my current system (Intel i3930K)… best speedup is about 6x using GPU vs no-GPU. That is significant.
https://forums.creativecow.net/thread/24/973364#973581

You can see that the GPU helps preview and rendering. But anything that’s speeding up the preview will speed up that same work, compositing and all, that’s needed for the final render.

Now, about that [b] part — it’s technically possible that the speed boost from a more modern GPU would run the Vegas accelerations so much faster than an older GPU, that this would offset the MainConcept improvements. And those would be enjoyed by the Sony CODEC and any other output rendering you do. However, checking on the available benchmarks, it looks like the HD6970 is faster than your HD7850 at many graphics benchmarks and OpenCL, but they’re not far apart even when the HD7850 wins. So you would get a speedup buying the HD6970. Makes some sense — they’re only one generation apart. That said, the HD6970’s peak power consumption is around 260W… twice that of the HD7850 — they got a die shrink from 40nm to 28nm in there as well. So make sure your PSU can handle it.

-Dave