Can't output native 2560*1600 60hz?

[ToastyX]

The first adapter won't work. Single-link DVI by specification only supports up to 165 MHz pixel clock. Anything beyond that is supposed to be dual-link. HDMI 1.4 is capable of going beyond 165 MHz pixel clock, but it's single-link, so you can't convert HDMI to dual-link DVI with a simple passive adapter. Some monitors can accept a single-link DVI signal beyond 165 MHz pixel clock, but that's not standard.

The second adapter might work. If it can do 3840x2160 @ 30 Hz, then it has the bandwidth to do 2560x1600 @ 60 Hz. The only question is whether it will pick up 2560x1600 without a custom resolution or EDID override.