New iMac performance with Capture One

I have been playing with an new iMac for about a week now and have done some very simple

experiments to measure performance.

I hope that they might be useful to anyone puzzling, as I did about what options 

to choose.

I have probably gone for overkill but I could easily imagine a situation in which Apple ditches Open CL before Capture One adopts Metal so here is the spec:

27 inch Retina Display

10 core Intel Core i9

16GB memory

1TB SSD

Graphics 5700 XT 16 GB

All images stored on the internal SSD

To test performance I used a 24 Mpx photo of trees with a complex Luma Mask and measured the delay time between a large shift in a slider and the display settling on its new appearance.

I found that the clarity slider showed the largest delay so the following results are for that slider only.

In all cases the preview size was 2560. The Low Res Display mode was 2560x1440 

Results

Display Retina Mode, open CL Off            Delay 3 secs

Display Retina Mode, open CL  Auto        Delay 0.5 secs

Display Low Res Mode, open CL Off         Instantaneous

Display Low Res Mode, open CL Auto      Instantaneous

In addition open CL makes a big difference in processing speed.

I processed 45 images to jpg in 35 secs using Open CL and 1min 20 secs without.

Since I can’t tell the difference in the resolution of a photo between Retina mode and Low Res mode then that is what I now use for photo editing. The benefit of the Retina display for me is the wider colour gamut. I do not use the iMac to display photos. For display purposes I use Print or a P3 display iPad or a P3 display TV.

Conclusion

If you really need the Retina resolution, maybe for much higher resolution images than mine, then it looks as if you are in Mac Pro territory.

As a rank amateur I probably could have saved myself some money on the Graphics card.

I hope that this helps.