The gofanco amazon page notes: – “Supports 594MHz 4K/60Hz bandwidth (SMPTE 4K) displays, as SMPTE 4K is the format available for HDMI 2.0. If the displayport monitor does not recognize the 594Mhz bandwidth, it will not convert. Monitors operating in 533MHz 4K bandwidth also will not work, unfortunately.”
This doesn’t make sense because I can force my computer to use a 533 MHz timing with my adapter (CMV-535) (but I can’t verify that the adapter is not converting that to 594 MHz on the DisplayPort end – but doing that seems like a complication to be avoided by any sane adapter manufacturer). No one else here has tried the 533 MHz custom timing with a PC, their adapter, and their display. That seems like important information to have…
The SIIG and gofanco web pages don’t mention the 594 MHz limitation. I don’t see why this limitation would exist, since the adapters are made to support arbitrary resolutions and timings.
SIIG and gofanco have a firmware update to improve compatibility, but I don’t know if it fixes the problems people are having here. The firmware updates are the same, confirming that both are the same product. I might try it with my optomedia CMV-535. The only difference between the updaters is the model number mentioned in the instructions.