2560x1080 has very low bandwidth requirements. At 60Hz even RBR works! Your cable would have to be almost completely broken for it not to work.

My video timings calculator shows exactly what kind of minimum protocol you need for a given video timing.

https://tomverbeure.github.io/video_timings_calculator

Oh wow, that's really useful, thank you!

Look at this table: https://en.wikipedia.org/wiki/DisplayPort#Refresh_frequency_...

Depending on the refresh rate, your cables are probably HBR.

Pretty much any cable will work at that resolution.

Problems usually happen at 4K resolutions, UWD resolutions (e.g. 3440x1440 and over) and especially at refresh rates over 60Hz.