I was lucky to very early on have one of those Voodoo cards, so it's kind of amazing how far we've come. Unfortunately, it's a true pain to determine whether o

I was lucky to very early on have one of those Voodoo cards, so it's kind of amazing how far we've come. Unfortunately, it's a true pain to determine whether or not a card matches reference. The reason is simple: if the layout changes, there's a good chance the water cooling block won't correctly align with the high points on the card. Having that happen means two things: you will have points where the block won't be making contact, or you will have to bend the PCB, or you will have a component not being cooled. All really bad things. This can even be impacted by the thermal pads used by the OEM. I mostly check to see if they're using the reference cooler design. I haven't bothered with AMD/ATI cards in ages, so this only really applies to Nvidia products. Cards with the blower style coolers with a single fan towards the rear of the card, with an output near the video outputs are almost always reference. Cards with coolers the OEM designs often are, but sometimes are not. That's mostly where things are annoying. Thankfully, water cooling OEMs often have specs from the start as to which cards will match if you're planning on buying day on. An example: With reference layouts the 980 and 980 Ti ought to be compatible. On some EVGA cards, you have memory mounted on the rear of the card, that makes backplate installation impossible depending on which backplate you use, as it'll teeter: either a 980 backplate, or one meant to be compatible with both the 980 and the 980 Ti. Worse, that can mean having to find a different set of screws to mount the water block you wish to use.