Comment by mlyle

I have thought about this a little more, and looked into things. Since NASA used the 360/91, and had a lot of 360's and 7900's... all of NASA's 60's computing couldn't quite fit into a single 486DX-25. You'd be more like 486DX2-100 era to replace everything comfortably, and you'd want a lot of RAM-- like 16MB.

It looks like NASA had 5 360/75's plus a 360/91 by the end, plus a few other computers.

The biggest 360/75's (I don't know that NASA had the highest spec model for all 5) were probably roughly 1/10th of a 486-100 plus 1 megabyte of RAM. The 360/91 that they had at the end was maybe 1/3rd of a 486-100 plus up to 6 megabytes of RAM.

Those computers alone would be about 85% of a 486-100. Everything else was comparatively small. And, of course, you need to include the benefits from getting results on individual jobs much faster, even if sustained max throughput is about the same. So all of NASA, by the late 60's, probably fits into one relatively large 486DX4-100.

Incidentally, one random bit of my family lore; my dad was an IBM man and knew a lot about 360's and OS/360. He received a call one evening from NASA during Apollo 13 asking for advice about how they could get a little bit more out of their machines. My mom was miffed about dinner being interrupted until she understood why :D