Forget what I said. The CAC-1510 has a real problem.
I have three of them. Two CAC-1510-A (HDCP OFF) and one CAC-1510 (HDCP ON). I don’t use them very often so I didn’t realize how bad the problem can be.
Of course, the CAC-1510 (HDCP ON) doesn’t produce an image with my Apple 30″ Cinema Display and macOS – the screen is black but it flickers the same as the black rectangle test image.
All the adapters appear to flicker. Connecting the adapters to a Thunderbolt dock doesn’t help.
I’m using the Intel GPU of a Intel Mac mini 2018. So it’s not a problem with M1 Macs. Normally, I use my Apple 30″ Cinema Display with a GTX 680 that has two Dual Link DVI ports – which have no problem with the display.
Only workaround is to not look at black screens… Black text on white background is ok but you may see some of the pixels in some of the black text flicker occasionally.
The flicker is not a loss of sync. It’s just outputting incorrect pixels every frame in varying locations. It mostly affects black pixels. It’s very noticeable with a black rectangle. The problem is greatly reduced when the black rectangle is changed to 5% brightness instead of 0% brightness.
Is the adapter doing something dumb like converting DisplayPort to analog and then converting that to Dual Link DVI?
I believe DisplayPort and DVI use 8b/10b encoding so there shouldn’t be a problem with a bunch of zero bits being transmitted.
Is it a problem having to do with limited range RGB (supporting 16-235 instead of 0-255)? If that were the case then colors would look off but they are not, and white pixels would be affected.
My firmwares are:
Club-3D CAC-1510-A HDCP OFF: HDCP_OFF_HD3_V1 2.33.102
Club-3D CAC-1510-A HDCP OFF (doesn’t have HDCP OFF on the label): same as above
Club-3D CAC-1510 HDCP ON: HDCP_ON_HD3_V1 2.33.102
(all of these use the Synaptics VMM2320)
I see Dell has an older firmware update for fixing flickering with a Dell U2417H display. I don’t know if it’s for the same kind of flickering.