[vox-tech] building an AMD MP system

Bill Broadley vox-tech@lists.lugod.org
Mon, 2 Feb 2004 23:08:26 -0800


On Sun, Feb 01, 2004 at 10:51:31AM -0800, Peter Jay Salzman wrote:
> hi all,
> 
> is the AMD 760 MPX the newest athlon MP chipset around?  it appears to
> be over 3 years old.

Indeed, but it's still the best for athlons.  The biggest difference is
the 512 MB/sec PCI bus instead of a 256 MB/sec.  They are also cheaper
often available without on board video like most of the MP chipset boards.

> via, ali and sis haven't come up with anything newer?  that's kind of
> hard to believe!

None of those companies got into the dual athlon market, they all came out
with numerous uniprocessor chipsets.

This is changing with opteron, at least nvidia plans to come out with
a SMP chipset.

> i'd like to run dual MP 2800's with barton core.  udma 133 or higher.
> built-in usb2.0 would be nice (although i understand that usb2 cards are
> dirt cheap).

There were usb2 bugs in the earlier MPX boards, most vendors threw
in a "free" pci card for usb-2.0.  I believe this was fixed.  IMO I wouldn't
invest a whole lot on such systems.  They tend to be rather heat sensitive,
definitely plan on keeping the environment cool, and having lots of fans.

Performance is often limited by the shared memory bus.

> any mobo recommendations?

I have 24 tyan MP boards, and 8 MPX boards and they all work quite well.

Keep in mind opteron-240s are $190, and the opteron dual motherboards
start at $240 ish.  The opterons feature (compared to the MP's)
	Much better perf per watt
	Double the registers (int, fp, and vector)
	SSE2 (athlon doesn't have it)
	Double the register size (larger pointers and ints)
	On board memory controller (lower latency)
	Per CPU memory interface (not shared)
	Dramatically better performance per MHz.
	Less total power.
	Few extra security features
	PCI-X (1GB/sec)
	Often sata is included in the motherboards.


-- 
Bill Broadley
Information Architect
Computational Science and Engineering
UC Davis