Data Center Energy Use
- The US spent the equivalent of 2/3 of Canada’s electricity use on data center’s last year.
- In 2006 that was 61 billion kilowatt-hours worth $45 billion – 1.5% of total US electricity consumption.
- That’s double of what was used in 2001.
- Data Centers are expected to double to 100 billion kWh by 2011 with the bill running up to $7.4 billion.
A coder friend of mine, in response to my question to him about the feasibility of “Exabyte” (a million Terabyte) arrays, responded with the energy draw such a data array would require (using current RAID 50 [mirrored RAID 5] drive technologies). His reply:
“Do the math. If you’re talking about COTS gear, you can get a 4U server which will hold 24 SATA drives. For mirrored RAID 5 (sometimes known
as RAID 50), you need 2(n+1) drives to hold n drives worth of data in a single array. With 1TB SATA drives (available next year), and a base array size of 6 drives, that means the 4U server can hold 10TB of RAID50 storage; put ten of’em in a 42U rack for 100TB of data. Ten racks is 1PB. So 1 XB requires 10,000 racks (roughly speaking) powering 100k servers (ignoring network infrastructure). Average power consumption for one of those servers is under 1kW; for the sake of argument, let’s call it 500W. So the data storage servers alone would draw 50MW. Add another few Megawatts for network infrastructure to string it all together and give you access; you’re talking 55MW. Add 50% overhead to the power consumption for cooling, ventillation, and lighting; call it 80MW total. And at $0.04/kWhr, $40/MWhr, that’s a power cost of $3200 per hour. More than $2.8 million bucks a year just to keep it all humming. Forget about cost of acquisition, rack’n'stack expenses, etc. And you have 2.4 million hard drives in there; what’s the MTBF for a 1TB drive? How many people will you employ simply to unplug failed drives and plug in new ones?
“The largest non-goverment data centers I know of (recent construction by Google, Microsoft, and Yahoo) run about 1/4 of that size (in the 12-14 MW range). That tells me this isn’t remotely feasible in a single location until 4TB drives become available (3-4 years, based on recent history; maybe longer). If you had ten datacenters worldwide and put 100PB in each, you could hit 1XB in the aggregate; but only a government could afford to put it in one place today.”
Very interesting. Lots of infrastructure challenges coming up.