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View Full Version : Dual Xeons in Windows 2000


GregHess
01-21-2003, 07:41 PM
Quick Note:

Alot of individuals do not run Service Pack 3 with Windows 2000. Here's another reason why.

If you are running Windows 2000 SP2 with a Dual Xeon system with Hyperthreading "Enabled" the OS will see the first two processors as the first physical, and the first logical, and miss the second physical processor completely. This of course means, if you are running win2k sp2 with a hyperthreaded system, either disable hyperthreading, or update to sp3...otherwise you'll lose a whole hella of a lot of performance.

This is fixed in Windows 2000 SP3 and allows the OS to see both physical processors. However the only way to make use of the secondary logical processors is either by upgrading to Windows 2000 Server, or Windows XP.

Carnifex
01-22-2003, 03:38 AM
Makes sense, since win2k Pro is designed to work with a max of two processors. Maybe they'll fix this in SP4...If there's gonna be an SP4.

dmeyer
01-22-2003, 03:57 AM
I've not seen any performance gains (at least during my workflow) by enabling HT on an already dual-proc system. I ran maya rendering tests (highend3d scene) on:

Win2K SP2, Maya 4.0: HT Enabled
Win2K SP2, Maya 4.0: HT Disabled

Win2K SP2, Maya 4.5: HT Enabled
Win2K SP2, Maya 4.5: HT Disabled

Win2K SP3, Maya 4.0: HT Enabled
Win2K SP3, Maya 4.0: HT Disabled

Win2K SP3, Maya 4.5: HT Enabled
Win2K SP3, Maya 4.5: HT Disabled

XP Pro, Maya 4.0(XP recognized 4 procs): HT Enabled
XP Pro, Maya 4.0: HT Disabled

XP Pro, Maya 4.5(XP recognized 4 procs): HT Enabled
XP Pro, Maya 4.5: HT Disabled

This test was run on a dual Xeon 2 ghz machine with 1gb of ECC PC800, when i was trying to decide whether to use XP or 2K on a new box.

All render times were within 1 second of one another, regardless of the system saw 2 or 4 processors.

elvis
01-22-2003, 04:28 AM
Microsoft WILL NOT enabled HT gains in windows 2000 pro. they have stated so on their own product pages.

if you want to use HT on a dual-xeon system, you must use either Win2K server or WinXP. simple as that.

microsoft couldn't be arsed adding features to old operating systems. instead it's up to the user to upgrade to "make use of the new hardware features", which can be read as "line our pockets some more, suckers".

HT gives some pretty decent gains on 3dsmax 5 renders (sometimes around 30%, depending on the scene). and also helps photoshop a little in some of the more SMP-friendly tasks it does. that's enough of an advantage to convince me to put up with the headache of upgrading a few of my users to XP. thanks to the wonderful world of corporate agreements, it doesn't cost me anything whichever OS i use. (free upgrades ahoy!!!).

GregHess
01-22-2003, 11:30 AM
Hey Dmyer...

You might want to make up your own benchmark, using a more complex scene at a much larger resolution. It might showcase some differences a bit better. (Try the highend3d test at 2048x1536 for example)

I hate to say it, but the resolution the highend3d test is run at is almost useless. You see little if any stress on the memory/bandwidth because of the resolution size. (The last time I checked the benchmark they were using that is)

You can really see this problem with their scores, as the faster systems are insignificantly different. A dual 2.4 Xeon should be alot more then a few seconds faster then a dual 2.2.

I just did some comparison testing with max5 and saw around a 5.8% gain. (Much less then all the websites are showcasing). Still 6% is 6%.

http://www.3dluvr.com/content/maxbench.php

I'm currently trying to setup some maya benchmarks and will get scores HT on/off back to you. (I'm also running vray, lw, xsi tests as well. The original max benchmarks are too pathetic to stress any of the new systems :( )

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