# Homework Help: IBM's Roadrunner Energy Consumption

1. Oct 27, 2012

### peripatein

Hello,

I am to find this supercomputer's energy consumption in GW/h a year.
I have found its consumption per hour to be 8.4402 GW/h.
How do I find the value per hour a year? Is it by simple multiplication by number of hrs a year (which doesn't seem right to me)?

2. Oct 27, 2012

### CWatters

In other words it's power consumption is 8.4402 GW.

So yes, just multiply 8.4402 GW by the the number of hours in a year.

3. Oct 27, 2012

### peripatein

But wouldn't that be its power consumption a year, and not 'per hour a year?'

4. Oct 28, 2012

### RTW69

Are you sure you didn't find the computers energy consumption in Gigawatts and you are looking for gigawatt*hours/year?

5. Oct 28, 2012

### peripatein

I am quite positive. That value was calculated based on data gleaned from the Wikipedia article. You may double check; I could have made a mistake. But does the computer work all year round? Do any other variables change throughout the year? It seems simply multiplying it by 24*365 will be over simplifying it. Yet I could myself be wrong. Any advice?

6. Oct 28, 2012

### RTW69

7. Oct 28, 2012

### CWatters

No. Energy consumption per year...

Remember Power = Energy/Time

so

Power(GW) * Time(H) = Energy(GWH)

or in SI units...

Power(in Watts) * Time(in Seconds) = Energy(Joules)

8. Oct 28, 2012

### peripatein

I am slightly confused. Which should it be then? And how do I calculate the hourly consumption a year?

9. Oct 28, 2012

### CWatters

Best avoid the expression "hourly consumption a year". If you want the know how much energy a super computer uses per year in "gigawatt hours" then RTW69 has the right answer...

10. Oct 28, 2012

### peripatein

Thanks a lot!