| In the PC space, as a disjointed semi-chronological overlapping timeline: In the beginning, we had ISA. We had ISA because it was cheap enough for IBM's PC, not because it was good. MicroChannel was a thing, largely limited to IBM, starting in 1987. It worked well. EISA was a thing. It was not ever particularly common or cheap. It had 32-bit width and 8.33MHz bus speed, in 1989. EISA's main features were that it was solid, and that it was not MicroChannel. It was backwards-compatible with ISA cards. Then VLB happened. It was fast, 32-bit, was often flaky, and it was cheap. It was very popular for all kinds of PC accessories -- not just video cards. Then, of course: Everything performance-oriented shifted to 32-bit PCI almost overnight (including some things outside of the PC space). But there as also a time when we had PCI-X (which is absolutely not an abbreviation for PCI Express). PCI-X was 64-bits wide at up to 133MHz (though 66MHz was more typical). Like EISA, it never became common or cheap. And eventually, we had AGP -- but only for graphics. And there was also PCI-X 2.0, which was like the previous version was 64-bits wide, but it could operate at up to 533MHz. It was theoretically excellent, but essentially never really existed: Widespread PCI Express adoption was right around the corner by then. And now, of course: We have PCI Express, which we've been successfully flogging along in various incarnations for a couple of decades -- a damned eternity in computer years. |