Asus PC-DL - Which processor.

[Wedge]

I have a new PC-DL MB and I'm thinking of getting two Intel Xeon 2.8
GHz 800MHz FSB, 1MB L2 Cache. Everybody calls out 512k cache.. Am I
going to gain anything by getting the 1MB Cache or should I save my
money? Also what are the experiences of people OC the xeon chips? I
figure I could get 3.2GHZ without too much trouble.

V/R Greg Wejrowski(AKA Wedge)

 

[Paul]

I have a new PC-DL MB and I'm thinking of getting two Intel Xeon 2.8
GHz 800MHz FSB, 1MB L2 Cache. Everybody calls out 512k cache.. Am I
going to gain anything by getting the 1MB Cache or should I save my
money? Also what are the experiences of people OC the xeon chips? I
figure I could get 3.2GHZ without too much trouble.

V/R Greg Wejrowski(AKA Wedge)

The list of what Intel sells is here:
http://www.intel.com/intel/finance/pricelist/

The supported CPU list is here, but it is missing enough info to
identify exactly what processors are compatible:

http://www.asus.com.tw/support/cpusupport/cpusupport.aspx

Notice how everything except the last three entries, has an FSB of
400 or 533. There are no FSB800 processors listed.

The last three entries in the Asus list for the PC-DL correlate
with the three most expensive MPGA2 packaged Xeon processors.
Those processors are all FSB533 0.13micron (Northwood era)
processors.

There was a raging discussion, about whether the PC-DL could
be tricked into running two processors at FSB800, as the
hypothesis was that the 875 Northbridge could do FSB800 on
a P4C800, so why not on the PC-DL. The thing is, when two
processors are present, the extra electrical load and multidrop
bus, shoot the good electrical properties of the bus to hell.
So, while the FSB on the P4C800 can be pushed to FSB1000 or
even FSB1200 (300MHz CPU clock), you cannot expect miracles
from a dual processor configuration.

This thread is extremely long now, and I don't plan on reading
it. Have a look and see if the participants made any progress
on coaxing FSB800 from the PC-DL. If anyone has managed to get
the new Xeons to work, then it might be worth a gamble. If
you advance to the last page of the thread, it looks like they
have discovered some mods to do to the board, to get more
from it:

http://forums.2cpu.com/showthread.php?threadid=40755

Most people with a board with that much horsepower, usually
opt for a stable conservative configuration. Selecting two
FSB533 processors is the safe thing to do. If you have a lot
of money to spend, then maybe you can reproduce some of the
overclocks in the above thread.

HTH,
Paul

 

[Wedge]

The list of what Intel sells is here:
http://www.intel.com/intel/finance/pricelist/

The supported CPU list is here, but it is missing enough info to
identify exactly what processors are compatible:

http://www.asus.com.tw/support/cpusupport/cpusupport.aspx

Notice how everything except the last three entries, has an FSB of
400 or 533. There are no FSB800 processors listed.

The last three entries in the Asus list for the PC-DL correlate
with the three most expensive MPGA2 packaged Xeon processors.
Those processors are all FSB533 0.13micron (Northwood era)
processors.

There was a raging discussion, about whether the PC-DL could
be tricked into running two processors at FSB800, as the
hypothesis was that the 875 Northbridge could do FSB800 on
a P4C800, so why not on the PC-DL. The thing is, when two
processors are present, the extra electrical load and multidrop
bus, shoot the good electrical properties of the bus to hell.
So, while the FSB on the P4C800 can be pushed to FSB1000 or
even FSB1200 (300MHz CPU clock), you cannot expect miracles
from a dual processor configuration.

This thread is extremely long now, and I don't plan on reading
it. Have a look and see if the participants made any progress
on coaxing FSB800 from the PC-DL. If anyone has managed to get
the new Xeons to work, then it might be worth a gamble. If
you advance to the last page of the thread, it looks like they
have discovered some mods to do to the board, to get more
from it:

http://forums.2cpu.com/showthread.php?threadid=40755

Most people with a board with that much horsepower, usually
opt for a stable conservative configuration. Selecting two
FSB533 processors is the safe thing to do. If you have a lot
of money to spend, then maybe you can reproduce some of the
overclocks in the above thread.

HTH,
Paul

Paul thanks for the reply.
But I dont plan on running FSB800, I was more interested in the larger
cache size. Is the MB going to see and use this cache or should I just
stick with 512k of cach.. I had planned on running the MB at FSB533..

V/R Greg Wejrowski (Aka Wedge)

 

[Ronald Cole]

Paul thanks for the reply.
But I dont plan on running FSB800, I was more interested in the larger
cache size. Is the MB going to see and use this cache or should I just
stick with 512k of cach.. I had planned on running the MB at FSB533..

Besides, it shouldn't be much longer before the 3.6GHz FSB800 dual
Xeon mainboards get here, should it? That's where I'm spending my
money...

 

[Paul]

(e-mail address removed) (Paul) wrote in message

Paul thanks for the reply.
But I dont plan on running FSB800, I was more interested in the larger
cache size. Is the MB going to see and use this cache or should I just
stick with 512k of cach.. I had planned on running the MB at FSB533..

V/R Greg Wejrowski (Aka Wedge)

They used a 1MB cache 3.06GHz processor in this review, so I guess
it is OK.

http://www.anandtech.com/mb/showdoc.aspx?i=1857&p=4

Due to the fact that the Xeons are sharing a bus, cache is more
important than on Opteron. Opteron boards have room for local
memory on each processor, and a cube shaped wiring for
interprocessor communications of up to eight processors - an
arrangement that reduces the need for cache.

Cache should help the Xeons, up to a point. At some point there
will be a diminishing return, and that is what you need to
research.

Here is a Xeon article DP versus MP. It uses server applications
for benchmarking and doesn't tell us much.
http://www.anandtech.com/IT/showdoc.aspx?i=1747&p=2

This article has strange results, and compares 512KB versus
1MB cache. The benchmarks are of the desktop variety.
The processors in this test are:
133 MHz FSB (Dual DDR266) Xeon 3.06 GHz (3066 12-8/512 KB)
133 MHz FSB (Dual DDR266) Xeon 3.06 GHz (3066 12-8/512/1024 KB)
The second processor has 1MB of L3, and both processors have
512KB of L2. It would seem the L3 is more effective in a server
environment, as the desktop benchmarks sees anywhere from no
improvement, to a minor improvement.

http://www.tomshardware.com/motherboard/20030827/asuspcdl-09.html

Really useful articles on Xeon are hard to find.

HTH,
Paul