RGB/32 bit preview, WARP vs. OpenCL [solved]

[NotMyFault]

Hi,

The RGB/32 preview in beta 1.10.5.1227 seems broken.

1. There is a big rendering discrepancy between WARP driver and OpenCL driver regarding gamma

When using regular renderer and OpenCL

1. Brightness is way off with default settings of exposure / gamma
2. Gamma slider is reversed in scale (opposite of Mac version)
3. rendering seems to be limited to 8 bit color depth. A document rendered ok in retail shows heavy banding in beta.
   Update: The effect was caused by No 2. After playing with the gamma slider, using a value of 0.45 instead of 2.2 (which i must enter as 0,45) eliminates the banding.
   So there is no difference between beta and retail.Meaning both beta and retaul share the same issue with gamma slider.

The screenshot apps seem to be unable to capture HDR content, and change brightness heavily when started.

 

 

 

display color bit tester RGB32.afphoto

[walt.farrell]

You seem to be talking about WARP and OpenCL as though they are the two rendering options.

The primary two rendering options are hardware or WARP, not OpenCL or WARP.

If you choose non-WARP (hardware) then you may have choices among different GPUs if you have multiple. And depending on the GPUs you have you may have two further choices: OpenCL or not.

Are you talking about a difference using hardware (regardless of OpenCL) vs WARP, or about a difference using hardware with OpenCL vs without OpenCL? 

[NotMyFault]

11 hours ago, walt.farrell said:

You seem to be talking about WARP and OpenCL as though they are the two rendering options.

The primary two rendering options are hardware or WARP, not OpenCL or WARP.

If you choose non-WARP (hardware) then you may have choices among different GPUs if you have multiple. And depending on the GPUs you have you may have two further choices: OpenCL or not.

Are you talking about a difference using hardware (regardless of OpenCL) vs WARP, or about a difference using hardware with OpenCL vs without OpenCL? 

I simplified the config options to no 1 and 4, as 2 and 3 gave equivalent to 4 during the tests I conducted in this report.

1. Warp
2. GTX1080 (manually chosen)
3. GTX1080 (Auto selection)
4. GTX1080 with OpenCL active

Intentionally I have chosen WARP as reference, as my beta accidentally run for the last weeks in that mode. As I have only 1 gpu, and OpenCL seems to be no distinguishing factor, I hope it is ok to condense in the way I did. In my case of single gpu system, I cannot think of no 2 and 3 make any difference at all.

Never the less, there is a small risk that the issues are OpenCL related (again, I tested briefly no 2 with OpenCL off and got identical results)

 

[walt.farrell]

Thanks for the clarification, @NotMyFault. If a brief test with configuration 2 showed the same results as configuration 4, it's likely hardware vs software, not OpenCL vs WARP.