The only short answer to this question is: maybe yes, maybe no. There are a number of things you need to figure out before.

Will my application run on a supercomputer?

Maybe yes, maybe no. All VSC clusters - and the majority of large supercomputers in the world - run the Linux operation system. So it doesn't run Windows or OS X applications. Your application will have to support Linux, and the specific variants that we use on our clusters, but these are popular versions and rarely pose problems.

Next supercomputers are not really build to run interactive applications well. They are built to be shared by many people and using command line applications. There are several issues:

  • Since you share the machine with many users, you may have to wait a while before your job might launch. This is organised through a queueing system: you submit your job to a waiting line and a scheduler decides who's next to run based on a large number of parameters: job duration, number of processors needed, have you run a lot of jobs recently, ... So by the time you job starts, you may have gone home already.
  • You don't sit at a monitor attached to the supercomputer. Even though that supercomputers can also be used for visualisation, you'll still need a suitable system on your desk to show the final image, and use software that can send the drawing commands or images generated on the supercomputer to your desktop.

Will my application run faster on a supercomputer?

You'll be disappointed to hear that the answer is actually quite often "no". It is not uncommon that an application runs faster on a good workstation than on a supercomputer. Supercomputers are optimised for large applications that access large chunks of memory (RAM or disk) in a particular way and are very parallel, i.e., they can keep a lot of processor cores busy. Their CPUs are optimised to do as much work in parallel as fast as possible, at the cost of lower performance for programs that don't exploit parallelism, while high-end workstation processors are more optimised for those programs that run sequentially or don't use a lot of parallelism and often have disksystems that can better deal with many small files.

That being said, even that doesn't have to be disastrous. Parallelism can come in different forms. Sometimes you may have to run the same program for a large number of test cases, and if the memory consumption for a program for a simple test case is reasonable, you may be able to run a lot of instances of that program simultaneously on the same multi-core processor chip. This is called capacity computing. And some applications are very well written and can exploit all the forms of parallelism that a modern supercomputer offers, provided you solve a large enough problem with that program. This is called capability computing. We support both at the VSC.

OK, my application can exploit a supercomputer. What's next?

Have a look our web page on requesting access in the general section. It explains who can get access to the supercomputers. And as that text explains, you'll may need to install some additional software the system from which you want to access the clusters (which for the majority of our users is their laptop or desktop computer).

Basically, you communicate with the cluster through a protocol called "SSH" which stands for "Secure SHell". It encrypts all the information that is passed to the clusters, and also provides an authentication mechanism that is a bit safer than just sending passwords. The protocol can be used both to get a console on the system (a "command line interface" like the one offered by CMD.EXE on Widows or the term app on OS X) and to transfer files to the system. The absolute minimum you need before you can actually request your account, is a SSH client to generate the key that will be used to talk to the clusters. For Windows, you can use PuTTY (freely available, see the link on our PuTTY page), on macOS/OS X you can use the built-in OpenSSH client, and Linux systems typically also come with OpenSSH. But to actually use the clusters, you may want to install some additional software, such as a GUI sftp client to transfer files. We've got links to a lot of useful client software on our web page on access and data transfer.

Yes, I'm ready

Then follow the links on our user portal page on requesting an account. And don't forget we've got training programs to get you started and technical support for when you run into trouble.