[bee_rider]

I’ll always wonder what would have happened if Intel had stuck with Pentium 4 and those incredibly long (31 stages! How we’ve fallen). Sure, they were power hungry, but at ~100W they don’t compare badly to modern chips. And dumping 100 Watts onto a single core is an extremely cool and fun thing to do. I wonder if we could have 10GHz processors for real by now.

[arcticbull]

Sorry, why do you say that the P4/Netburst microarchitecture doesn't compare badly to modern chips? Their performance was utter garbage (at the time, and now) which is why the Pentium M architecture (a Pentium III derivative) was used when they built out Core. AMD was spanking them at the time with the K8/Athlon 64 and the Athlon 64 X2.

A super long pipeline allows higher clock rates but it takes a giant dirt nap when branch prediction fails and when you have a cache miss. You end up having massive latencies in these cases.

Further, generally all else being equal a lower clock rate allows you to be more energy efficient.

[bcrl]

The worst part of the P4 was when it went off into la-la land for 4000 cycles of replay. Did you issue a locked instruction? 4000 cycle penalty. Use rep ; movs? 4000 cycle penalty. Some weird internal condition with a misaligned store? 4000 cycle penalty. One could optimize to improve performance in those cases, but the performance glass jaws on the P4 were all consuming.

[bee_rider]

Just in terms of power consumption they don’t compare badly. Performance, of course, no comparison, haha.

Agree that it had tons of problems. But branch prediction has gotten better, compilers have gotten better, etc. Maybe they could be handled now!

[smolder]

Anything salvageable from the architecture likely has been used again by this point.

[xgkickt]

(Edit: With modern core counts) I think we’d be seeing partnerships with GE, Whirlpool, Rheem etc ;)

[bee_rider]

Exactly! We barely interact with our dishwashers, refrigerators, and water heaters. We just fill them up and empty them out occasionally. Boring! But we’re willing to devote hundreds or thousands of watts to them and dozens of square feet of floor space to them. Computers are much more interesting, therefore they deserve that same appliance treatment.

I’m kidding in these sense that I don’t think a single core could be designed to usefully use 1000W. I get why things happened as they did. But I do still think single threaded performance is much more interesting than multi-core, so I wish we could see how those designs would have evolved.

[xgkickt]

There’s so much waste heat that could be diverted into hot water storage.

[bee_rider]

At the time you’d start up your computer, then go make some coffee or tea while it booted. Imagine if that could be combined into one process!

[gpderetta]

Time for a custom water cooling loop!