A decade ago I figured we be at 10ghz by now, didn't count on more cores instead of faster.
Of course you cannot compare 1ghz in 2003 to 1ghz in 2013, way more efficient per clock cycle with the right code.
Of course you cannot compare 1ghz in 2003 to 1ghz in 2013, way more efficient per clock cycle with the right code.
Take Pentium 4 - which used the architecture Intel was working on when they were predicting that they'd have 10GHz CPUs by now. Passmark's score for a 3GHz Pentium 4 is 384.
An i7-3940XM runs at 3GHz, and gets a score of 10,490. That's a quad-core computer, so I'm going to go ahead and be sloppy by dividing by 4 to get a score of 2622.5 per core.
In other words, a single i7 core is doing almost seven times as much work per clock cycle. And assuming they only ramped up the clock rate, the P4 would have to be running at over 20GHz to match what the i7 is doing on a per-core basis.
Given the heat dissipation problems that come into play with high clock rates, that seems like a doubtful proposition. In hindsight, it looks like Intel definitely made the right choice by dumping the NetBurst plan and instead letting clock rates stagnate (they've even retracted a bit from the high water mark) while designing the processor core to do a lot more with each cycle.
Seems to me memory getting 10x more bandwidth and cache getting 8x larger probably accounts for the majority of the performance differences between these processors not instructions per cycle, which I think has gone up by more like 2x.
So a Pentium 4 with current memory and cache would need to be more like 8 Ghz if it scaled linearly like that (P4 had ~3 instructions per cycle, i7 ~7-8).
At 10Ghz, something moving at the speed of light can only go around 3 centimeters per clock cycle. Take out gate delays, and you wind up with something that just isn't practical.
Our future CPUs should be tiny cubes, not flat chips.
Distance to each point in 3 dimensions is shorter.
Now turn them sideways, so they rest on the edges. Put the stack in a small ceramic container with copper bottom and top. Fill with a high efficiency thermal transfer fluid, and make sure the convection currents flow properly.
There you go, small matter of engineering.
The T2 processors from Sun had over 100 threads per chip. Its a shame that they didn't do better in the market place.
The important things that changed were that smaller cores tend to leak more, which means that voltage had to be scaled down aggressively. And drive currents are now limited by velocity saturation.
And you probably still shouldn't. Quantum computing only provides a speedup for a very specific set of problems. For the vast majority of everyday computing tasks, quantum computing offers no practical advantage over classical computing.
This is what change looks like. Our intuition can be correct yet we still have to be open enough to recognize it when we it actually happens.
OTOH, quantum computers continue to not ship as a product.