[Beowulf] Athlon64 / Opteron test

[Daniel Fernandez]

Hi,

We're studying the possibility of installing a 64 bit testing node.

The main purpose is about getting impressions related to the performance
increase we would obtain in our particular scenario, computational fluid
dynamics.

In order to do the test, we have no doubt about the OS: Red Hat
Enterprise 3, but we are a bit confused about the harware of choice:

		Athlon64
		Opteron

As far as we know, Opteron has two main differences:

	- A wider memory interface (128 bit in front of 64)
	- A larger L2 cache memory (1 Mb)

Before doing any test, the questions are:

1)

 Which is the theoretical maximum performance gain using full 64 bit
architecture in front of 32 bit, taking into account that our
computations are done in double precision floating point using really
big matrices?

2)

Is it nowadays the 64 bit solution using Linux ready for production?
If this is the case, which problems may we have to deal with in order to
compile and run our code in a full 64 bit environment?

3)

Which is the most mature solution: AMD Opteron or Intel Itanium?

-- 
Daniel Fernandez <daniel at labtie.mmt.upc.es>
Heat And Mass Transfer Center - CTTC
www.cttc.upc.edu
c/ Colom nº11
UPC Campus Industrials Terrassa , Edifici TR4