The layout of a typical PC case is both very space inefficient and has suboptimal airflow at the same time. Drive bays are mostly obsolete. GPUs take multiple slots of absurd dimensions. Square motherboard requires putting PSU somewhere on the side, increasing overall case dimensions. It's a 3D Tetris with poorly fitting blocks.
Now every case I buy will have outdated IO in less than 10 years.
I guess a bus interface is tricky, but it might be interesting to design systems in this way.
One other system design I remember was the old "lunchbox" case, where a system with expansion slots had a tilt-out display and separate keyboard. I think it would make for a powerful portable system, but laptops seem to have extinguished this idea.
VME was a successor, and I use VPX which has PCI Express (or any switched fabric if you're ambitious enough) on the backplane, at my day job every day.
https://en.wikipedia.org/wiki/VPX
I wish VPX was more widely-adopted. You can get processor modules, the modules can have XMC mezzanine cards for add-ins like GPUs and NVMe drives, 10-gig (and faster) networking (including switches and routers) over the backplane, RAID storage arrays, FPGA modules, and more all in a rugged chassis.
You can get compact 3U boards and can make NUC-sized systems, or use the full-sized 6U boards and go nuts cramming capability into a printer-sized boxes.
But because it is almost exclusively limited to the aerospace/military domain everything is obscenely expensive.
A cheaper, less rugged, consumer-focused version could transform computing: easy tool-less upgrades, no clearance/compatibility issues with GPUs, cable-less desktops, and extreme modularity.
You could have an 8-bay chassis the size of a NAS from Synology or QNAP with 8 slots, with 2 for CPU, 2 for GPU (or 1 each for low-power devices), 1 for storage, 1 for advanced pro audio, 1 for video capture, and 1 with a bunch of M.2 slots for massive storage arrays. Need to upgrade your gpu? Just pull a handle and slide it out, and slide the new one in.
One can dream!
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\* Hash-Mode 2000 (STDOUT)
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Speed.#1.........: 39068.9 GH/s (0.02ms) @ Accel:64 Loops:1024 Thr:512 Vec:1
What does 39 trillion (!) password hashes per second from a single GPU imply for password length/complexity these days?an 8-character password with the usual upper/lower/special mix can be cracked in <1 hour by a single RTX 4090.
I wish it were scrypt, PBKDF2 or argon2id - but I realize those are still rare.
I wonder how many sites are still using md5...