[iforgotpassword]

It's complicated, but the tldr is: use a DP++ type 2 adapter that advertises 4k compat.

DP++ adapters tell the GPU to output an HDMI signal instead (DP is an entirely different protocol), and then just level-shift the signal. Type 1 adapters are limited to i-forgot-how-many MHz which means no more than 1080p60. Type 2 adapters contain a tiny 256 byte rom that tells the GPU its maximum supported bandwidth.

Other adapters are active, they convert the signal and thus add latency, and often need external power so can get quite hot.

[jasomill]

I haven't noticed any perceptible latency from any active DP → HDMI I've used, and I'd honestly be surprised to see any inexpensive active DP → HDMI adapter introducing latency, if only because doing so would require a frame buffer, which drives up costs.

What I have seen is DP → HDMI adapters that only support chroma subsampled pixel formats at 4kp60, and TVs that introduce many frame times' worth of latency due to various post-processing effects.

My hunch is as follows: given that consumer video devices (DVD/Blu-ray, set top box) almost exclusively output chroma-subsampled 4:2:2/4:2:0 YCbCr formats, TV post-processing pipelines may only support these formats, causing RGB (and possibly 4:4:4 YCbCr) signals to bypass post-processing, similar to the "PC" or "Game" modes present on some TVs that do the same.

In other words, if adapter → 4:2:2/4:2:0 and 4:2:2/4:2:0 → TV post-processing → latency, then adapter → latency, even if the adapter itself introduces no significant latency.

If I'm correct, the solution is an adapter which supports RGB output at the desired resolutions and frame rates and/or a TV with a PC/Game mode that bypasses post-processing for all source types, both of which are highly desirable for "monitor" use in any case.