cluster or not?

[ekdya]

Hi

I was reading about supercomputers which lead me to Mosix and setting
up 2 or more linux boxes. I use linux and windows. I would like to
have 3 linux boxes in a cluster, do I go and build my own nodes from
scratch with PCI-E based motherboards and the rest or there is a
better way to go about the hardware.
I mean if what does the work is the cpu, wouldn't 2 linux boxes with 1
cpu each be equal to one box with 2 CPUs? in this case.

thanks[/list]

 

[belvdr]

This depends entirely on what you want to use the cluster for. There are many things doing "work" inside any system, be it memory, disk, or CPU.

For example, if you are utilizing the processors heavily, then a single two cpu node may perform just as well as two single cpu nodes. However, if you are doing heavy disk I/O, then it may be better to have two systems so as to have two different busses for the data to cross.

The hardware should be architected for whatever purpose you need it for, which means finding the right cards/disks/processors for the OS and application you intend to use. For example, in an Oracle database cluster, I really don't care whether I have a 2.6Ghz CPU or a 3Ghz CPU, as I'm relying mostly on disk. That said, I would most likely spend less money on CPU, and more money on a faster disk array.

The first question you need to ask is: What do I plan on doing with this cluster? Not all applications are clusterable, nor does having a cluster speed things up all the time. Research is your friend here.