Supercomputers Get Eco-Aware


Twice a year, the computing world waits to hear whose processors and which vendors will claim the equivalent of a gold medal for building one of the world’s fastest supercomputers as measured by the Top 500 nonprofit. This year it was IBM’s $100 million Roadrunner machine, which can reach speeds of 1 petaflop (about 1,000 trillion calculations per second). It also consumes a whopping 3 megawatts of power.

But today’s is the first Top 500 list to ever track power consumption of these machines and the results are only semi-encouraging. The fastest computers, surprisingly, do not consume the most power. The average power consumption of a Top 10 system is 1.32 megawatt and the average power efficiency is 248 megaflops per watt.

Older machines on the list are using more less power, but are just not as efficient. The average supercomputer on the Top 500 list has a power efficiency of 122 megaflops per watt. (The press release also says the average consumption of a Top 500 supercomputer is 257 megawatts — we’re pretty sure they mean 2.57 megawatts, but we’re waiting to hear back on that.) Update: They got back to us to tell us that the average Top 500 power consumption is actually 257 kilowatts. That actually gives me hope that all the energy-efficient chips coming out recently can help this problem.

Ironically, many of these computers are engaged in the very types of climate modeling programs or protein folding operations that could one day help the environment. It’s encouraging to see that the number of calculations per watt is trending up and that average power consumption seems to be trending down with newer machines at the top of the list.

However, the demand for power in these computers is crazy high (for comparison, an average desktop consumes about 80 to 150 watts), which explains why scientists at the Department of Energy’s Lawrence Berkeley National Lab are hoping to figure out a more energy efficient way to build a supercomputer using embedded processors.


Stacey Higginbotham

Thanks for the reply guys, and we’ve adjusted the story. The 257 megawatts blew our mind :)

Erich Strohmaier

Indeed, we had a typo on our web-site. The average power consumption of a TOP500 Supercomputer is 257 kilowatts. Keep in mind that these numbers do not include cooling or other facility specific features such as UPS.



The Top10 impressive power efficiency figure (248 Megaflops per watt) is the direct consequence of IBM leadership in both computing capability and power efficiency. Five out of ten are IBM systems using IBM processors (Cell Broadband Engine, Blue Gene) which are the most power efficient processors.

The Top500 average power consumption must be 257 kilowatts, or 0.257 megawatts.

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