Amazon Elastic Compute Cloud (Amazon EC2) is a web service that provides resizable compute capacity in the cloud. To test its capabilities with Zemax, I used a High-CPU Extra Large Instance, which is the most powerful single block of computing power offered:



It's good to understand the terminology here. A "Compute Unit" refers to the basic block of computing capacity the Amazon cloud offers, and is not specifically a CPU. I created a machine image of a Windows Server 2003, 64-bit operating system, which appears to have 7 GB and used 20 compute units to appear to have 8 virtual CPUs. Task Manager on the virtual machine reported 8 Xeon E5410 @ 2.33 GHZ. I connected to the virtual machine using Remote Desktop.

Installation of the 64-bit October release of Zemax was straightforward. As a virtual machine has no USB port to plug the Zemax in, a network key was used, and the virtual machine was simply given the IP address of the keyserver machine to log the license out of.

I then ran two tests that I commonly use to assess the horsepower of a machine:

• First I loaded the double Gauss sample file, (Samples\Sequential\ Objectives\Double Gauss 28 degree field.zmx) used Tools...Miscellaneous Performance Test, and obtained 125 million ray-surfaces per second.
• To test non-sequential ray-tracing I then loaded the sample file \Samples\Non-sequential\Geometry Creation\Boolean Example 3-  a diffractive scattering Boolean object.ZMX, and traced all the Analysis rays with scattering, splitting etc in 7.1 seconds.

For comparison, my desktop machine (a Dell Precision 690) has 8 Xeon X5355 CPUs @ 2.66 GHz, and 8 GB RAM and gives

• double Gauss: 93 million ray-surfaces per second
• Boolean sample file traces in 5.5 seconds

For further comparison, another desktop machine (Dell Precision T5700) with 8 Xeon 5450 processors @ 3 GHz gave

• double Gauss: 157 million ray-surfaces per second
• Boolean sample file traces in 4.1 seconds

With all three machines, 100% CPU utilization was achieved with both tests.

In summary, the performance of the Amazon cluster was very impressive, on a par with well-specified standalone workstations. I was also very impressed with the ease of use of the Amazon EC2 system. Amazon charge $1.20 per hour for the use of a virtual machine of this performance, with no sign-up fees or monthly fees. We will be keeping an eye on developments in this area, and will keep this article updated with future developments.

The good news is that Zemax works with this technology out of the box, with the need for a network rather than physical key the only implementation issue.