Posts Tagged 'amazon'

Comparing Plura to Amazon’s EC2 for High Performance Computing

Amazon has recently come out of beta with their EC2 service, as noted by several sources:

EC2 has been extremely successful since its launch.

I’d like to do a quick comparison between Plura and EC2 for high performance computing.  (Note: All EC2 information was taken from Amazon’s website.)

Compute Performance

EC2 High-CPU Medium Instance nodes provide 1.7 GB of memory, 350 GB of instance storage and local network accesses between EC2 nodes at no charge.  Plura nodes vary in memory and size and we never use the disk.  Plura applications can request nodes with a minimum memory size if necessary.  Also, Plura nodes are not connected.  Each node knows only about its own tasks and can’t share with others.  This lends Plura to what’s called embarrassingly parallel applications of HPC.  That said, we have techniques for making some very difficult algorithms embarrassingly parallel.

Plura has a significant advantage over EC2 in terms of amount of available computing power.  Right now, the maximum # of nodes a customer can have on EC2 is about 1,000 to 3,000 nodes.  On Plura, customers have access to the entire node pool, which is currently over 50,000 nodes.  This gives Plura users significantly more compute power.


Each EC2 High-CPU Medium instance costs $0.20/hour.  This is equivalent to paying $1752/year for a  5-6 GHz CPU.  Plura charges approximately $100/year for a 2 GHz CPU (the average speed of nodes on our network).

The “conversion factor” between Plura nodes and EC2 nodes would be 2.5 Plura nodes = 1 EC2 High-CPU Medium Instance.  So Plura charges $250/year for the equivalent of 1 EC2 node, while Amazon charges $1752/year.

Side note: If you need to use EC2 nodes with Internet bandwidth, the $/year goes by $1000s/year for each node.  For now, Plura builds this in for free.


For HPC applications that need a lot of inter-node communication, EC2 will probably suit your needs better even at a higher cost.  However, if your application is suitable for Plura, you can save 7X on your compute costs.  If you need the equivalent of 1000 5 GHz nodes for a year, Plura will save you over $1.5 million ($250K vs $1.75M).