Microwulf: Frequently Asked Questions

  1. Will Microwulf run [insert favorite program/game] faster?
  2. Can I build a Microwulf using Windows?"
  3. I want to build a Beowulf cluster. Where can I learn how?"
  4. How did you mount the motherboards to the plexiglas?
  5. Is Microwulf a commercial product? Are you selling them?

  1. Will Microwulf run [insert favorite program/game] faster?
    Unless the program has been written specifically to run in parallel across a network (i.e., it has been written using a parallel library like
    message passing interface (MPI)), probably not.

    A normal computer with a multicore CPU is a shared memory multiprocessor, since programs/threads running on the different cores can communicate with one another through the memory each core shares with the others.

    On a Beowulf cluster like Microwulf, each motherboard/CPU has its own local memory, so there is no common/shared memory through which programs running on the different CPUs can communicate. Instead, such programs communicate through the network, using a communication library like MPI. Since its memory is distributed among the cluster's CPUs, a cluster is a distributed memory multiprocessor.

    Many companies only began writing their programs for shared-memory multiprocessors (i.e., using multithreading) in 2006 when dual core CPUs began to appear. Very few companies are writing programs for distributed memory multiprocessors (but there are some). So a game (or other program) will only run faster on Microwulf if it has been parallelized to run on a distributed multiprocessor.

  2. Can I build a Microwulf using Windows?
    The key to making any cluster work is the availability of a software library that will in parallel run a copy of a program on each of the cluster's cores, and let those copies communicate across the network. The most commonly used library today is

    There are several versions of MPI available for Windows. (To find them, just google 'windows mpi'.) So you can build a cluster using Windows. But it will no longer be a Beowulf cluster, which, by definition, uses an open source operating system. Instead, it will be a Windows cluster.

    Microsoft is very interested in high performance computing -- so interested, they have released a special version of Windows called Windows Compute Cluster Server (Windows CCS), specifically for building Windows clusters. It comes with all the software you need to build a Windows cluster, including MPI. If you are interested in building a Windows cluster, Windows CCS is your best bet.

  3. I want to build a Beowulf cluster. Where can I learn how?
    There are many websites that describe how. Here are a few of them:

  4. How did you mount the motherboards to the plexiglas?
    Our vendor supplied
    screws and brass standoffs with our motherboards. The standoffs have a male/screw end, normally screwed into the case; and a female/nut end, to which the motherboard is screwed. To use these to mount the motherboards, we just had to:
    1. drill holes in the plexiglass pieces in the same positions as the motherboard mounting holes;
    2. screw the brass standoffs into the holes in the plexiglass pieces; and
    3. screw the motherboards to the standoffs.

    To prepare each plexiglass piece, we laid a motherboard on top of it and then used a marker to color the plexiglass through the motherboard's mounting holes. The only tricky parts are:

    We used a red marker to mark the positions of the holes on motherboards facing up, and a blue marker to mark the positions of the holes on motherboards facing down.

    With the plexiglass pieces marked, we took them to our campus machine shop and used a drill press to drill holes in each piece of plexiglass.

    When all the motherboard holes were drilled, we stacked the plexiglass pieces as they would appear in Microwulf and drilled holes in their corners for the threaded rods.

    We then screwed the standoffs into the plexiglass, taking care not to overtighten them. Being made of soft brass, they are very easy to shear off. If this happens to you, just take the piece of plexiglass back to the drill press and drill out the bit of brass screw that's in the hole. (Or, if this is the only one, you can just leave it there and use one fewer screws to mount the motherboard.)

    With the standoffs in place, we then placed the motherboards on the standoffs, and used screws to secure them in place. That's it!

    The only other detail worth mentioning is that before we screwed each motherboard tight to the standoffs, we chose one standoff on each motherboard to ground that motherboard against static. To do this grounding, we got some old phone wire, looped one end to the standoff, and then tightened the screw for that standoff. We then grounded each wire to one of the threaded rods, and grounded that threaded rod to one of the power supplies.

  5. Is Microwulf a commercial product? Are you selling them?
    No, and no, mainly because we know nothing about business.

    But we are trying to build an endowment to provide in-house funding for student projects like Microwulf, so if you've found this site to be useful, please consider making a (tax-deductible) donation to it:

          CS Hardware Endowment Fund
          Department of Computer Science
          Calvin College
          3201 Burton SE
          Grand Rapids, MI 49546

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