Differences between AMD and Intel CPUs [was: Re: Dragonfly andHyperthreading....]

[David Xu]

EM1897 at xxxxxxx wrote:

In a message dated 3/9/2005 6:22:30 PM Eastern Standard Time, David Xu <davidxu at xxxxxxxx> writes:

 

EM1897 at xxxxxxx wrote:

   

If you paid that much for an SMP system running FreeBSD,
then you're flying blind for certain. You've overpaid 
because you don't know enough about hardware to know
what you're doing. Your xeon systems "sound like jets"
because you've bought something that sounds like a jet.
A P4 system with a single blower (which is what we use)
will likely outperform what you've bought for 1/5th the
cost. (my current 5.3R benchmarks show that FreeBSD
with 2 3.06Ghz xeons is actually slower than a single
P4 processor system. They've done a helleva job!).
     

I benchmark by passing packets through the box until it
starts dropping packets. So there is no "package" to fail.
5.3 runs at about 90% with 650Kpps with a single 3.06
xeon, and starts dropping packets at 300Kpps with dual
processors. It seems ridiculous, but its so much slower
than 4.x that its not worth much of my time.
 

You've hit the wall then, I don't think 5.3R has a SMP aware TCP/IP stack,
Robert Watson and other guys did lots of work in 6.0-CURRENT, that
should already be improved, but I don't know if it can match performance of
RELENG_4.
David Xu