Why isn’t CPU time more valuable?

Here’s something I find puzzling: why isn’t CPU time more valuable?

I first thought about this when I was working for MD Anderson Cancer Center, maybe around 2002. Our research in adaptive clinical trial methods required bursts of CPU time. We might need hundreds of hours of CPU time for a simulation, then nothing while we figure out what to do next, then another hundreds hours to run a modification.

We were always looking for CPU resources, and we installed Condor to take advantage of idle PCs, something like the SETI at Home or GIMPS projects. Then we had CPU power to spare, sometimes. What could we do between simulations that was worthwhile but not urgent? We didn’t come up with anything.

Fast forward to 2019. You can rent CPU time from Amazon for about 2.5 cents per hour. To put it another way, it’s about 300 times cheaper per hour to rent a CPU than to hire a minimum wage employee in the US. Surely it should be possible to think of something for a computer to do that produces more than 2.5 cents per CPU hour of value. But is it?

Well, there’s cryptocurrency mining. How profitable is that? The answer depends on many factors: which currency you’re mining and its value at the moment, what equipment you’re using, what you’re paying for electricity, etc. I did a quick search, and one person said he sees a 30 to 50% return on investment. I suspect that’s high, but we’ll suppose for the sake of argument there’s a 50% ROI [1]. That means you can make a profit of 30 cents per CPU day.

Can we not thinking of anything for a CPU to do for a day that returns more than 30 cents profit?! That’s mind boggling for someone who can remember when access to CPU power was a bottleneck.

Sometimes computer time is very valuable. But the value of surplus computer time is negligible. I suppose it all has to do with bottlenecks. As soon as CPU time isn’t the bottleneck, its value plummets.

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[1] I imagine this person isn’t renting time from Amazon. He probably has his own hardware that he can run less expensively. But that means his profit margins are so thin that it would not be profitable to rent CPUs at 2.5 cents an hour.