Poor OpenCL Performance on Nvidia GeForce 9600 GT

[realjab]

Hi all,

Recently I borrowed a Nvidia GeForce 9600GT graphic card. I'm using it in my Ubuntu 13.10 with 1.2.0.7 of AfterShot Pro. AMD Phenom 4cores and 8 gigas RAM. Nvidia driver 304.

I have enabled OpenCL and have made some test enabling and disabling OpenCL. I have executed the Full JPEG batch for a set of 40 images with typical editions, some cropping, some exposure adjustment, wavelet portlet and little more.

Those are my results:

With Standard OpenCL Level set in preferences: 141 seconds
With Minimum OpenCL Level set in preferences: 69 seconds
Disabling OpenCL: 58 seconds

So it seems to me that in my configuration OpenCL is just slower and not worth using. It raises some questions to me.

1) Is this due to the actual status of the implementation of OpenCL in Corel AfterShot Pro or is it due to my hardware? I now the Nvidia GeForce 9600GT is quite old but I thought that some OpenCL assistence would be better than no assistance at all.
2) Which graphic cards models or series or range would be worth using to improve performance?
3) OpenCL performance boost is only useful for batch outputting or it also improves the experience during editiong and adjustment ?

And finally:
Apart from color management and resolution capabilities if not using OpenCL, does AfterShot Pro take any advantage from a graphic card that is "better" than another or is just everything else managed by the processor?

Thanks

[spoilerhead]

@ 1) ASP will move some pipeline stages to the GPU, if it's slower than your processor then your processing time will increase.

[afx]

On my Linux quad i7 laptop with an Nvidia card OpenCL is slower than CPU only (Nvidia 319).
On my Quad Phenom AMD Windows desktop with a FirePro card, I get a 25% speed increase with OpenCL.
Your Nvidia driver is stone age, you might try a new one (which reminds me, I should repeat my test with the current driver (331)).

cheers
afx

[shurito]

there was a test in the german "c't digitale photografie" magazine, where they tested the performance of OpenGL with Aftershot Pro and Capture One by using different GPU's of Nvidia, AMD and Intel.
They tested a GeForce 210 (53 seconds), GTX 650Ti (37 sec), GTX 660 (35 sec) and GTX 680 (33 sec.) for converting the same set of 100 NEF-Files to 8-Bit Tiff.

The conclusion was that GPU acceleration is just useful for graphic cards starting at 80€ and that theres no huge difference between more expensive and cheaper ones. AMD offered the best cost-performance ratio and performance at all (but maybe not under linux...)

Personal, I've an GTX 460 in my tower with debian testing and it's not useful for ASP, it even slows down the converting process.

Edit: For comparison:
Intel HD 3000 (58 sec.)
Radeon HD 7970, HD 7870 and HD 7750 (all 30.sec.)

[realjab]

Updating to 319 driver doesn't seem to improve anything in fact it seems even a bit worse, 150 seconds with standard OpenCL.

[rkswamy]

The 9600GT is over 5 years old now. I tested on a GTX 550 Ti with a Core i7-860 and found that for processing Nikon D3 it was 39% faster with OpenCL. When processing D800 images it was 28% slower using OpenCL. My bigger problem was that turning on OpenCL caused it to crash a lot and also even when done processing it would use 1 CPU at 100% which caused the fan to stay loud and use more power.