Any benefit of upgrading CPU in video rendering when using CUDA render ?

[Vladimir 1]

Hi,

Can anyone please tell me if I would get any benefit in rendering time if I upgrade my current CPU ( Intel Xeon E5620 2,4 GHz overclocked to 3,6 GHz ) to Intel Xeon E5645 2,4 ghz ? Well, as far as I know these 2 CPUs are pretty much the same, except the fact that the Xeon E5645 has 2 more cores and 4 more threads so if I buy it, I'll overclock it using the same settings I use now and get it to 3,6 GHz too.

Anyway, as far as I have noticed using CUDA render gets me about 50% faster rendering compared to CPU only render and this is the reason why I always use CUDA rendering.
Though when I did a test ( with an overclocked cpu and not overclocked CPU, so 3,6 GHz and 2,4 GHz ) using CUDA render, the render times were the same, I didnt see any time difference and this is really making me wonder if upgrading my CPU to get 2 cores and 4 more threads will improve anything regarding the rendering time.
Usually when I use CUDA render, I see that both the CPU and GPU load are about 70%.

I know it would be 50% boost when using the CPU only render option, but this is not the case Im asking for.

I would really appreciate an answer from somebody who knows for sure, somebody who understands how CUDA render exactly works.
In case this is needed, my GPU is MSI Nvidia GTX 560 Ti Twin Frozr ii OC and my RAM is Kingston 3x4GB DDR3 1600 MHz and the software I use is Sony Vegas Pro.

Thank you.

 

[Alaric]

There is also no guarantee you'll get the same OC with a different/ more cores chip. As a (very) vague guideline, more cores=lower MHz. There are always exceptions, every CPU will have its own personality. I'm not familiar with using CUDA, but for rendering, more cores can be better than higher clock speed anyway.

 

[JLK03F150]

I thought CUDA was completely managed by the GPU, so a faster video card (or one with more CUDA cores) is what will speed up rendering more than any CPU improvement.

 

[Vladimir 1]

I understand that a more powerful GPU will speed the render, but the one I have ( GTX 560 Ti Twin Frozr ii OC ), I bought it like 2 months ago just because of this, probably the best I could find for the money I was able to spend and among the best one for the software I use.
When it comes to CUDA render, Sony Vegas Pro works best with the GTX 500 Series, it's not optimized to work with newer GPUs so in this case upgrading it to a newer GPU will actually be a step down for me. I guess I can benefit more if I upgrade my card to an AMD Radeon HD card because the software works better with Radeon cards, but to be honest it wont be a big difference I guess and wont be that cheap either.

So you think there is no point I should upgrade my CPU if I continue using CUDA render ?

Thanks.

 

[Kenrou]

I tried several weeks ago to get that program to work with my 980ti and kept telling me CUDA acceleration wasn't available, something in the drivers is preventing it from using them for video editing. There's several x264/x265 encoders (free or otherwise) that give the same issue.

 

[Vladimir 1]

Yeah I've heard that CUDA render just wont work with newer graphics drivers so you should really consider installing some older drivers for your GPU, maybe 2014 drivers or older.

 

[Johan45]

If vegas can use more cores the new CPU will be faster for rendering. Won't change the CUDA portion much but the CPU portion will. Do you know if the SW uses HT ?

 

[Kenrou]

Uses all threads available.

 

[Vladimir 1]

Yes, the software uses all cores and all threads and as I mentioned before, I am aware that upgrading to the CPU will be helpful if I render using the CPU only render, but I also mentioned that I do not use CPU only render, I always use CUDA render and this is the reason I created this thread to get an answer if it will be worth upgrading considering the render type I use or just stick to what I have.

 

[Johan45]

My last experience was with bluray software and the "CUDA" and CPU work together to render the entire file. If the CPU has the ability ( ie. more cores/threads ) it'll pick up more work and reduce the time.
I switched from a PII 965 to an FX 8350 and it significantly reduced my render times using the same GFX card to assist with CUDA

 

[Vladimir 1]

Alright, thank you very much for your reply.

I'll definitely think about this, but I guess upgrading would really help me out in the render times considering that not every effect/ transition I use can be rendered by the GPU, plenty of them can be rendered only by the CPU so this is where it can help a lot.