[Tfug] AMD vs. Intel floating point

[Brian Murphy]

Quoting John Gruenenfelder <johng@bach.as.arizona.edu>:
> I am trying to put together an upgrade for a machine at work.  Our
> primary concern is number crunching power, especially floating point
(lots of
> FFTs much of the time).  A number of place I have read show benchmarks
> with AMD chips ahead of Intel chips in FPU performance, but finding *good*
> benchmarks is very hard.
> 
> In particular, the machine is a choice between 2x Athlon MP 2600 (the
> 2700s not being available yet) or 2x Pentium 4 3Ghz.  There is, of course,
> a pretty big price difference too, but more important is FPU speed.
> 
> Does anybody have any good links to benchmarks either way?  Any
> experience in which is better?
> 

Of course the best solution is to test your code on both.  You may see
things like CPU cache play a giant role depending on your program.

The SPEC tests are often cited benchmarks.  See
http://www.spec.org/cpu2000/results/ .  There is a 2600+MP Athlon in the
1st Q 2003 results and a bunch of P4s and Xeons in 4thQ 2002.

In short, the P4s look faster.
(I hope this table formats okay)

CFP2000 Rates
Company  System                                                        
                         CPUs  Base Peak
AMD  Asus A7M266-D Motherboard, AMD Athlon (TM) MP 2400+    2  10.5  11.2
AMD  MSI K7D Master Motherboard, AMD Athlon (TM) MP 2600+   2  10.4  11.0
Dell     PowerEdge 6650 (2.0 GHz Xeon MP)                              
             2  13.2  13.8
Dell     Precision WorkStation 530 (2.4 GHz Xeon)                      
           2  13.5  13.8

The AMD benchmarks also show how important a good motherboard is.

Brian

The opinions or statements expressed herein are my own and should not be
taken as a position, opinion, or endorsement of the University of Arizona.