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FAQ

How many wall plugs does a DEXTER personal cluster need?

Four. There are four individual power supplies in the DEXTER cluster case, one for each individual computer.

You may also need one additional if you prefer supplying the LAN switch by its own power supply instead of the master node power supply. This will take altogether five wall plugs.

How can I distribute calculations among nodes of a DEXTER personal cluster?

First you need an Operating System which supports cluster computing. It could be one of the Linux distributions like Scientific Linux or it may be a version of Windows Server (have not tried it yet).

The other component you need is your software let it be either an engineering simulation software or an image renderer or something else. The software you want to use and the license you have for it must be be capable of handling job distribution among several computers.

Some of the software tools like one of our Fluid Dynamics simulation tools can only do distributed computing if you have the necessary license to run such calculations.

Some of the open source codes in the fluid dynamics world like OpenFOAM as an example can run distributed computing without any further licensing requirements.

How can I reach the nodes of a DEXTER cluster running Linux from my Windows laptop?

We recommend using VNC software to visually check up on individual workstations of a DEXTER personal cluster.

VNC stands for Virtual Network Computing.

If a DEXTER personal cluster node runs for example SUSE Linux as the Operating System, we use X11VNC on the Linux nodes to be the server of the VNC connection. On the Windows laptop we use UltraVNC as viewer.

When you have a VNC connection like this you can work on each DEXTER node while watching the screen of your Windows laptop.

Basically this method makes your laptop a screen with keyboard and mouse, the work is done on the DEXTER personal cluster.

Can the CPUs of the workstations in a DEXTER personal cluster be different?

In theory yes, but we will not build one like that. It is because if we use a DEXTER personal cluster in cluser mode the best performance can only be expected if all workstations have the same main components. Cluster mode means that all workstations have the same Operating System and software package on and you run distributed computing on all or some of the nodes.

If a motherboard, a processor or memory type were different (slower) from the others this slower node would be the bottleneck of the whole system.

How the individual workstations are connected to form a DEXTER personal cluster?

The patented DEXTER cluster case we use to mount every component into has a built-in 8-port Gigabit Local Area Network (LAN) switch.

This network switch provides the network connection among the four workstations to form the cluster. A DEXTER personal cluster uses only 4 ports out of 8 of the LAN switch so you have the possibility to connect other computers like your laptop or an other DEXTER personal cluster to the first cluster.

The power supply of the 8-port LAN switch is the same as the power supply of the master node or its own power supply can be used as an alternative.

Is there any difference among individual computers in a DEXTER personal cluster?

Can be, depending on the configuration you would like to consider. In a DEXTER personal cluster there are four computers (we also call them nodes). One always has an ATX-size motherboard, we call it the Master node. This is the one which has its connectors visible on the back panel of the DEXTER cluster case.

The other nodes (we call them slaves) may have an mATX-size motherboard but the CPU and memory type is always the same as for the master node. If they are all ATX because the CPU can only be fitted in an ATX-size motherboard, then there is no difference among the types of motherboard and of course CPU’s are the same as well.

Other components may be different like the number of hard drives attached to the slave computers.

How many CPU cores a DEXTER personal cluster can take?

On products page you can find two example configurations: DEXTER 16 takes 16 CPU cores (32 threads), DEXTER 40 can take 40 CPU cores (80 threads) altogether.

Since we have four workstations installed, a 16-core DEXTER has 4 CPU cores in each workstation. Usually these CPUs are the latest Intel Core i7 processors with the highest clock frequency available.

A Core i7 CPU can fit in an mATX-size motherboard. In this case the three DEXTER slave nodes are based on mATX motherboards. The DEXTER master node is always based on an ATX-size motherboard.

To have 40 cores altogether in your DEXTER personal cluster you need a Xeon processor if you prefer Intel as CPU manufacturer. In this case all four workstations are based on ATX-size motherboards. This motherboard size provides more memory (RAM) per workstation, more graphics card can be installed but as a whole, your personal cluster would consume more energy.

As CPUs evolve, the number of cores/CPU increases contunuously. We decided to scale our product range between 16 and 40 CPU cores. This may change in the future depending on CPU development.

What are the differences between DEXTER personal cluster configurations?

The main differeces are in the number of Central Processing Unit (CPU) cores, the amount of memory (RAM) and as a consequence the type of motherboards.

Depending on CPU types and the number of CPU cores the CPU socket (with which a CPU is connected to the motherboard) could be different and not all motherboards can take all CPUs.

For example if you wish to have a 10 core CPU for each workstation within your DEXTER personal cluster, this determins the size and type of the motherboard because a 10-core CPU can only be installed on an ATX-size motherboard. This motherboard is one size bigger than an mATX (micro-ATX) format and provides more features, more connectors (USB, network, etc.) than its smaller counterpart.

So the first thing we recommend for you to decide is the number of CPU cores because this determins a lot of other components.

Which components every DEXTER personal cluster has?

Every DEXTER personal cluster has:

  • Patented DEXTER cluster case,
  • Four motherboards with CPU, RAM and other components to make a fully operational workstation node,
  • Four power supplies,
  • Hard drives to store software and user data,
  • An 8-port switch that connects all four workstations into a cluster,

 

Is DEXTER personal cluster a supercomputer?

Yes, a small one.

To simplify things a little bit a supercomputer is made of individual computers connected by a high-speed network. They consist of several hundreds of computers making 1000’s of CPU cores.

In a DEXTER personal cluster we have four individual computers and they are connected by a high speed network. Not that high speed as used in big supercomputers though.

So yes, it is a small supercomputer with capabilities designed to fit the needs of professionals who have grown out the computing power of their single-computer workstation and want the power of cluster computing by their office desk.

Please check Applications for living examples.

Where does the name DEXTER come from?

The name DEXTER comes from the phrase DESKside clusTER, the internal name of the project of building our own small supercomputer. Yes, we know. The X is missing but if you try to say deskside cluster fast, it is almost there.

Now you see it is quite difficult to pronounce it, especially several times a day. We needed a shorter version so it became DEXTER.

Since it is a proper small supercomputer for personal use for professionals, then we named it DEXTER personal cluster computer.

Why is a DEXTER personal cluster unique?

It is unique because of the specially engineered case we use to mount all components into. It is our own patented design, our own way of arranging components within the case. The DEXTER case provides room for four workstations and all other components necessary for a cluster and ensures proper ventilation.

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