There are several reasons why you might not want to bother trying. I just bought a new video card so I went through this recently. - It's possible that X->Z a

There are several reasons why you might not want to bother trying. I just bought a new video card so I went through this recently. - It's possible that X->Z adapters are rare/discontinued/nonexistent/whatever, so you need to stack X->Y + Y->Z. If the adapters are active, now you need 2 more power supplies (or USB ports) just to run each display. - There's many combinations of stacked adapters that don't work together, for various reasons, so this can involve a lot of research, and a bit of luck. - Even if it basically works, it's common that not all features of every protocol are supported by every other protocol. I can control the brightness of one display from software (it runs directly over DVI), but not my other display (which runs over a DP->DVI adapter). - It's also common that a lot of adapters just don't work. I've got an active adapter here that the manufacturer and retailer both swear supports dual-link DVI, but it doesn't. I eventually found a review online from someone who tore it apart and looked up the specs on the chip inside. It only supports single-link resolution. Bogus. - There's also many passive DP->DVI adapters which claim to support dual-link, even though this is (apparently) electronically impossible. More lies. - I have what seems to be the only working DisplayPort to dual-link DVI adapter, and it wasn't cheap (>$100). It also takes several seconds to wake up, and during that time it displays static and noise and off-color versions of my desktop. It's not the most pleasant experience. - Newer displays are much less power-hungry than older models, so if you pay for electricity and have your displays on a lot, it's definitely cheaper to just upgrade that. - I've also tried to convert (single-link) DVI-D to HDMI. Apparently it should be just a physical adapter, as the signals are electronically compatible in that direction. For two devices I have, when run at 1080p, the picture comes out horribly distorted. Each device supports 1080p, but when connected in this particular way, it's unwatchable. No idea why. Any time you have to convert formats, there's potential for trouble. That's why I'm not optimistic about the new USB-C/Thunderbolt world of "we'll just encapsulate every other protocol in the world". When I've got devices and adapters strung together and it doesn't work, who do I call for support? One of Norvig's rules from PAIP was "Whenever you develop a complex data structure, develop a corresponding consistency checker". I wish I had test equipment for every port type in my house, but I don't, and that's not feasible for most people.