I realize that there’s quite a few 10-bit posts already but browsing through them they seem either old or asking about specific components. Apologies if this is somewhat redundant, happy to be re-directed to existing info if it exists.
We are setting up a visual psychophysics setup to measure luminance discrimination thresholds. Our preliminary tests suggests 8 bit is sometimes too close to psychophysical threshold and I’m considering building a 10-bit setup.
My Question would be what would be the recommendation in terms of hardware/software.
At the end of this post from 2022 (Hardware and software set up for 10-Bit stimuli) I read “In general, the best tested (by myself with a CRS ColorCal2) and most powerful setup for such high precision stimuli is modern Linux with a modern AMD graphics card”, so I’m guessing we want Linux. That’s fine. I don’t have strong requirements in terms of the size of the monitor.
I would appreciate suggestions on:
True 10-bit monitor. Most affordable that will do the job well.
Same for GPU. Post above mentions “modern AMD”. A specific model would help.
Calibrator. The CRS ColorCal MkII mentioned in the post does not seem to be available anymore. I just asked CRS for a quote of their available CCCal-3. I would hope this is supported by PsychToolbox.
Any other hardware requirements
If there is a particular version of Linux that is recommended, that would be good to know too.
Thanks a lot
Alfonso Renart
Champalimaud Neuroscience Programme
Lisbon, Portugal
That advice for Linux + AMD is still true. Linux with a modern AMD graphics card, ie. pretty much anything from AMD Polaris onwards (introduced with the Radeon 400 series in the year 2016) is possible for up to 12 bit per color channel (12 bpc) support over DisplayPort or HDMI, either native for high end 12 bpc display monitors, or via spatial dithering to the more common 10 bpc monitors. Needs the AMDVLK Vulkan driver installed as optional install. All described in help PsychImaging in the section about native 16 bit framebuffers. Even older AMD gpu’s back to Sea Islands from around 2014 would be technically possible, but that’s old stuff and setup gets painful. 10 bpc only framebuffers are also possible with NVidia (not recommended in general), and also all Intel graphics chips since the year 2010, however Intel does not allow to simulate 10 bpc on 8 bpc displays via dithering, only native 10 bpc displays. A downside of the 10 bpc modes of graphics cards other than AMD’s, using other than the Vulkan display backend, is that Matlab has a bug reported to Mathworks half a decade ago and unfixed since then, which crashes Matlab in 10 bpc mode, unless running in a terminal window via matlab -nodesktop or having a separate X-Screen for visual 10 bpc stimulation in a dual-display setup. Ofc. one can also use the free Octave, which doesn’t have such problems.
No comment. Apart from the recommendation that connecting via DisplayPort may be better or more foolproof than HDMI sometimes. The HDMI standard in its infinite wisdom forces any HDMI connected 10 bpc capable monitor to also advertise itself as being fully able to support 12 bpc input, even if the hardware can’t actually do it, and simply truncates any 12 bpc input down to 10 bpc. This can cause the graphics driver to think the display wants to be driven 12 bpc, when 10 bpc would be preferrable. So if the monitor is 10 bpc only and connected via DisplayPort then there’s less chance of such foolishness.
Any modern AMD gpu should work. Tested gpu’s by myself are listed in PTB help texts, but these are more than 5 years old, so probably only available used from eBay. I tested on a few more laptops from friends from around 2020/2021, some more modern, which confirms this general finding, but don’t remember models. I can’t test on more modern hardware due to the severe lack of funding, no money for more modern recent equipment.
I don’t know if the ColorCal-3 works, didn’t even know it exists before reading your post. If the programming interface is backwards compatible to ColorCal-2 then I’d guess it would work.
Don’t think so, as long as it runs modern Linux.
Ubuntu 22.04-LTS brings all the needed stuff apart from the AMDVLK driver which needs to be manually installed in the right version, and was tested at some point. All later versions should also work. help PsychImaging has the needed setup instructions for AMDVLK.