As you're probably aware of by visiting tech sites like ours, 4K displays (monitor and TV both) are slowly but surely spreading through consumers this Holiday thanks to some pretty great deals. However, some gamers have had 4K displays since last year and in those cases, there's a strong chance their hardware doesn't support HDMI 2.0.

　　That includes my Asus 4K monitor, which is why I was particularly happy to find out from Eurogamer's Digital Foundry PS4 Pro tech analysis that Sony added a YUV240 mode capable of 2160p(4K)@60Hz even on HDMI 1.4 displays.

　　2160p YUV420 is interesting in that this allows PS4 Pro to connect to older 4K screens that lack the full HDMI 2.0 implementation. By reducing chroma information, the required bandwidth drops down in half, allowing HDMI 1.4 screens to get a full 60Hz signal.

　　The compromise is that hard reds, blues and greens can show low resolution artefacting. However, in our tests, we've found that it's not an issue in a typical living room environment. 2160p RGB doubles the bandwidth requirement, meaning HDMI 2.0 is a must, and sends the framebuffer through losslessly to the 4K screen.

　　This reassured me that I would be able to play at 2160p resolution, albeit with a slight reduction in chroma information. This weekend, though, I bought the PlayStation 4 Pro console only to find out that it didn't allow 2160p@YUV420 after all.

　　I turned out to the Internet and quickly found an existing eight-page thread on the official PlayStation Europe forums full of complaints on this issue. Apparently, 2160p@YUV420 mode worked fine with firmware 3.70 (which PS4 Pro was shipped with) but suddenly became unavailable for all HDMI 1.4 display owners once the firmware was updated to version 4.05.

　　Needless to say, this is a very frustrating situation for all those users who should be able to set their PlayStation 4 Pro at 2160p@YUV420 but are prevented from doing so and subsequently forced to stick with 1080p. There's been no official word from Sony Interactive Entertainment yet and we can only hope that they'll fix this in an upcoming update. We'll keep you updated should there be any developments, of course.