CPU vs GPU performance for Sony Vegas 13

[queensoft]

I have lots of [simple] projects using [Sony] Vegas Pro. I'm using version 13 right now, I will upgrade to 14 soon.
My computer right now is i5 3470 with Intel HD 2500, 8 Gb RAM DDR3, 1 SSD for Windows 7, 1 Tb HDD for files and projects, MSI GT 630.
The projects are rendered at 1080p mostly, using Sony AVC. 90% I will not need 4K in the future.
Project length ranges from 5 to 50 minutes. Source material is MP4 videos, images, lower third graphics, titles, very few FX.

Render time example, using a 5 minute project:
- Intel QuickSync speed = 04m:25s
- CPU = 07m:20s
- nVidia GPU = 12m:05s

I want to upgrade my computer to this: i7 6700K with Intel 530, 16 Gb RAM DDR4, AMD R9 390.
I have seen a lot of benchmarks with this video card or similar (390X, 290, RX 490....) and the results are very good.
But all benchmarks are testing video cards only, not CPU vs GPU. And Intel video cards are not included.
So, my questions is: which of these will be faster: Intel GPU, CPU or AMD OpenCL ?

 

[Multipack]

Hardware rendering is always much, much faster, but at the cost of quality. Software rendering (like x264) primarily needs CPU horsepower though can be aided by GPU acceleration.. As it says here, speed is prioritized over quality.. https://en.wikipedia.org/wiki/Intel_Quick_Sync_Video

 

[queensoft]

Quality is perfectly acceptable for me when using QuckSync Speed setting - that is not the problem.
The problem is what is faster: i7 6700K, Intel 530 QuckSync or AMD R9 390 OpenCL ?

I just did some testing, using Teamviewer, with this setup: i5 3570 @ 3.40 GHz, 8 Gb RAM DDR3, Sapphire R7 260X, Windows 7 x64, Sony Vegas 13.
Very very disappointing.

Using my exact same project, rendering times were:
- CPU: 08m:13s
- GPU, Sony AVC, Render settings: Encoding mode: GPU if available: 07m:18s
- GPU, Mainconcept, Render settings: Encoding mode: OpenCL: more than 10 minutes.

I think Mainconcept does not support OpenCL, but the program still allows selecting the options.

But, here's the problem: GPU-Z: GPU Load shows low usage (6-50%) and very very rarely, hardly ever GPU usage, like some short spikes every 15-30 seconds.
Almost the entire time GPU is not used at all !
When I use Intel QuickSync on my computer, GPU Load is constantly at 80-90%.

 

[Multipack]

QuickSync is the i7 6700k. Thats the same thing. Open CL will be much faster - as will Nvidia's NVENC..

IQSV (CPU encoder) or software's own encoders or writing libraries like x264 will barely use your GPU at all unless you utilise GPU acceleration (slowly being replaced by NVENC and OpenCL), but I dont personally use Sony Vegas so cant tell you whether it's available in that software. If you use IQSV and you are seeing GPU usage though, it must.

It's more a case of understanding the concept behind video encoding. Only OpenCL support will fully utilise your GPU.

 

[queensoft]

QuickSync is NOT CPU.
It is the video card embedded on the CPU.
CPUs without embedded video card do not have the QuickSync option.
Please check my testing with i5 3470 with Intel HD 2500, there's a huge difference:
- Intel QuickSync speed = 04m:25s
- CPU = 07m:20s
Also, using the EXACT same project, files and settings, i5 3570 and R7 260X the difference is minimal:
- CPU: 08m:13s
- GPU, Sony AVC, Render settings: Encoding mode: GPU if available: 07m:18s

 

[Multipack]

Actually it's a core on the processor die, effectively the same thing, i.e hardware encoder much like NVENC, which isnt quite the same as Open CL which doesnt employ CUDA cores, primarily because AMD cards dont have any, and can be used by Nvidia cards as software, but the CPU alone can't encode, it has to use a writing library like x264, so it uses processing power to run software encoding. You can't encode with the CPU lol....

 

[queensoft]

Right, ok, it's a core, not OpenCL, not CUDA.
But then how do you explain the big time difference ?!

 

[Multipack]

Becuse hardware encoding is faster than software encoding,. When you say CPU, what is happening is it is powering (slower) software encoding, possibly x264 or x265 etc, which are higher quality. All software requires a CPU computer.

 

[queensoft]

All right, QuickSync is a dedicated core. Not CPU, not video card.
But, from 174 CPUs with QuickSync, only 3 do not have a video card embedded: https://ark.intel.com/search/advanced?QuickSyncVideo=true&MarketSegment=DT
So, for the sake of simplicity, I will still say QuickSync is GPU rendering using on board Intel video card.

 

[queensoft]

I'm even more confused now, after doing some more research
Starting from R9 390, I stepped down to R9 290x (a bit cheaper and almost exact same performance), then even more back to Radeon HD 6970 (cheaper even more and better performance - I think).
Now, based on this article - http://www.hyperactivemusic.com/vegaspro/vegaspro.html - I'm thinking of a GTX 580.
It's even cheaper and almost the best performance - if I read the table corectly: Render Mainconcept = 36 seconds.
Again, I'm only interested in fastest rendering, I don't care about quality and editing/timeline preview.
Also, unfortunately, another problem arose: I need a better PSU, right now I have 450/500 W (can't remember exactly).
So, would anyone recommend the GTX 580, with current i5 3470 and new PSU ?