I think it comes down to when you want to build your
computer. If you want to build it today, and you want
dual processor, then you aren't going to get a DDR
board. Your choices are SDRAM or RAMBUS (or, if you
want to go to a real server board that supports true
SMP beyond 2 processors, EDO SDRAM).
For dual processor SMP, you can go with the tried
and true BX based boards, which have some bottlenecks
if you push them to the limits in pushing data (but
are still quite good, quite cheap, and extremely stable).
You can go for the VIA/Apollo based boards, which
promise much with their 133Mhz FSB, but don't deliver
in either performance or reliability. You can go
for a SeverWorks designed board. These boards
have 133Mhz FSB, better reliability than the VIA/Apollo
AND more bandwidth for pushing data than the BX
boards. But they're a bit quirky if you want to use
them outside of the server environment. For example,
they support AGP graphics poorly. And the IDE channels
on the boards seem to have been an afterthought, offering
pretty dismal performance. (Not an issue for CDroms
and whatnot, but a big issue if you plan to run IDE
hard drives instead of SCSI drivse).
And then there is the Intel OR840, so far the only
dual platform that supports RDRAM. RDRAM has been
much maligned, in large part because it was SO
much more expensive when it was introduced and
didn't show performance improvements anywhere
near those promised...However, prices for RDRAM
have dropped dramatically...And benchmarks of
the OR840 are quite good. In most benchmarks
it beats any other dual processor motherboard
out there...
If you want to go beyond 2 processors, then you have
only one option in the Intel/AMD world: The
Xeon servers. An entry level machine would be
Intel Cabrillo SC450NX server, which supports
4 Xeons and up to 4Gb of memory (EDO SDRAM) costs
about $3000. High end Xeons (PIII 700Mhz/2Mb cache)
run a couple of thousand apiece. Memory is about
$1500-2000 per Gb. Not for the faint of heart.
And, of course, at that level, you need to think
about SGI, Fujitsu, and others.
If you are willing to wait (how long? who knows. Probably
at least a half year) then you may be able to get a
dual AMD board that supports DDR. AND, initial reports
indicate that even when this board is actually available,
it isn't going to be a barn-burner.
For an interesting comparison of the ServerWorks motherboard
with the not-yet-available Via/Apollo DDR based board,
the Intel OR840 and a Tyan board, check out this link:
http://www.anandtech.com/showdoc.html?i=1414
Personally, I don't see anything here yet that would make
me wait for DDR if I wanted to build a computer in the
very short range future.
dap
Bill Ross wrote:
>
> David Konerding as usual has an authoritative answer going down to the
> details. It confirms my more general conclusions based on a look at
> this issue a few weeks ago:
>
> Isn't there at least 1 board now with double-clocked memory (DDR, maybe
> only for Athlon)? If so I'd consider getting that or waiting for
> a few more boards to appear. I looked at RDRAM after being ridiculed
> on a Photoshop group for suggesting it, and lost interest based on
> price, design (serial rather than parallel access of memory banks),
> and the double-clocked alternative.
>
> Here's a place to look at PC proposed designs:
>
> http://arstechnica.com/guide/system/
>
> Also interesting:
>
> http://www.anandtech.com/
>
> Bill Ross
Received on Fri Feb 09 2001 - 17:16:42 PST
