The old Cray-1s certainly are iconic and beautiful machines. Just from my personal experience working in HPC for the last 15-20 years, what I think is driving us away from these cool old-school designs (Thinking Machines were always my favorite) is the sheer size of modern supercomputers.
They're just staggeringly large, and there's no way you could get them built, disassembled, shipped, and reassembled without these racks. (They still do come in custom racks a bit bigger than normal, and inside they look nothing like normal racks.) It's an event when the trucks all show up to unload these things and the only thing that makes them manageable is that it's a normal form factor on a pallet you can move around with a jack. Additionally, at least in my experience, a good portion of them usually gets sent back so you're always in there taking them apart and putting them back together. Anything "creative" would just get in the way.
I can't get a good hyperlink on my phone to an artists rendition of Titan at Oak Ridge Road or Mira at Argonne (the ceiling is too low so you can't photograph all the racks at the same time, but do a Google Image search for it.) It's staggering just how big it actually is. They may not be that unique looking any more, but they're still damned impressive in person (until you have to fix one. Then the magic wears off pretty quickly.)
Edit: I do wish they would stop putting the murals on the side of them. I think a big noisy $300,000,000 black box has a certain cosmetic appeal to it that they ruin with the flashy plastic covers.
They're just staggeringly large, and there's no way you could get them built, disassembled, shipped, and reassembled without these racks. (They still do come in custom racks a bit bigger than normal, and inside they look nothing like normal racks.) It's an event when the trucks all show up to unload these things and the only thing that makes them manageable is that it's a normal form factor on a pallet you can move around with a jack. Additionally, at least in my experience, a good portion of them usually gets sent back so you're always in there taking them apart and putting them back together. Anything "creative" would just get in the way.
I can't get a good hyperlink on my phone to an artists rendition of Titan at Oak Ridge Road or Mira at Argonne (the ceiling is too low so you can't photograph all the racks at the same time, but do a Google Image search for it.) It's staggering just how big it actually is. They may not be that unique looking any more, but they're still damned impressive in person (until you have to fix one. Then the magic wears off pretty quickly.)
Edit: I do wish they would stop putting the murals on the side of them. I think a big noisy $300,000,000 black box has a certain cosmetic appeal to it that they ruin with the flashy plastic covers.