cluster hardware

Being a newbie to clusters this might be a dumb question. I haven't seen it directly answered anywhere so I am going to venture out on a limb and ask...

I understand that each data node in a cluster needs the same amount of RAM . However, how will different cpu counts/hard drive setups and such affect the performance. Not talking celeron vs/quad core, but some systems might have raid and four cores while some might not have raid and only have two cpus. Does the management node monitor things and distribute the nodes or should I try as hard as I can to have equal hardware on the boxes?

thanks,

Keith

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B. Keith Murphy 
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