Titan Supercomputer

[invinible]

I noticed that 1 of the rules for using the Titan Supercomputer is that what you are doing needs to required at least 1/5th of the system to be done.

[factotum]

Originally Posted by Neftren

factotum, you don't always want to run at 100% CPU load. Electricity costs really add up when you're running a supercomputer (or even just a data center).

According to another article I found, this machine uses 9MW of power at full load. At the sort of prices they charge for electricity in the UK (approx 20p per kWh), that would be £1800 an hour or a little under £16 million per annum. Now, what I *can't* find is how much this machine cost to build in the first place--I suspect that number is going to be very high compared to that estimated electricity cost, though.

That's significant, because it goes back to what I was saying earlier--if the machine spends most of its time idle you could have built a less powerful, cheaper one to do the same task.

[Winter_Wolf]

Maybe they have an unadvertised, private source of power for it. Secret nuclear reactors in basements, people! [/tinfoil hat]

I just thought the original article I linked to was sloppy for not even giving the kinds of projects that needed that kind of power, or at least some ludicrous comparison like running 1000 copies of some kind of software that people might have heard of.

[Neftren]

Originally Posted by factotum

According to another article I found, this machine uses 9MW of power at full load. At the sort of prices they charge for electricity in the UK (approx 20p per kWh), that would be £1800 an hour or a little under £16 million per annum. Now, what I *can't* find is how much this machine cost to build in the first place--I suspect that number is going to be very high compared to that estimated electricity cost, though.

That's significant, because it goes back to what I was saying earlier--if the machine spends most of its time idle you could have built a less powerful, cheaper one to do the same task.

I'm going to define "idle" as "0-1% utilisation" at this point, just so we're all on the same page. Correct me if your definition if idle is different, and we can revise from there.

Anyways, back to cost-benefit analysis. Some rough Googling presents a $1.2bn price tag for Japan's K supercomputer, currently #2 on the TOP500 list. Peak consumption is 12.6 MW, though further down the page, it lists 9.89 MW, so let's go with the latter number as the expected figure.

They're comparable I suppose. I'd have to do some more research on Titan though.

I do have to say though, that the arguments presented thus far comparing supercomputers and regular consumer computers don't really apply. First off, any large computing center will probably be running around 60-70% load, but that's an aside (remember electricity scales exponentially). The average user might think "oh, a bigger computer means a faster computer!" when that really isn't always the case. Sure you can use a big computer to accelerate your programs, but what's of more interest is that a bigger computer allows you to solve bigger problems. Some programs only gain a limited benefit from tacking on more cores, and need an alternative approach when switching to parallel.

It's not about building a less powerful, cheaper one to do the same task. Sometimes it's about building a bigger machine that can handle a larger-sized problem, courtesy of the terabyte or more of RAM attached to the thing. Atmospheric simulations come to mind here, if you're trying to model a very large region (or the entire planet, in Climate simulations).

[Stu42]

Originally Posted by Winter_Wolf

Maybe they have an unadvertised, private source of power for it.

Row upon row of hamsters in wheels.