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VRay without 2 CPU´s
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These pages are a copy of the official truespace forums prior to their removal somewhere around 2011.
They are retained here for archive purposes only.
VRay without 2 CPU´s // Hardware
Post by Vizu // Aug 31, 2006, 1:55am
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Vizu
Total Posts: 628
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I have a chatsession yesterday with Lizardking and he makes me afraid.
Told him that i plan to buy 2 X Intel Xeon Dual Core CPU´s and he mean it is possible that VRay for Truespace don´t support 2 CPU´s mit Core kernels.
Can it be that VRay for TS can not use the power of a dual CPU board with 4 cores ? |
Post by Asem // Aug 31, 2006, 2:29am
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Asem
Total Posts: 255
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I've myself have mean to test that out as I have a dual xeon with 2 sockets I even have the VRM chip (needed to have the motherboard recognize the 2nd processor at least on mine) and the 2nd processor (got it from a friend) at the moment though I'm having a problem getting the VRM chip in (I think one of the slot's flippers is messed up and will have to take take a knife to open it up a little very carefully). VRay runs pretty fast on the one Xeon processor (3.06Ghz) hopefully when I get the second one in it will take advantage of it hearing this:)
Another thing, when I put in the seond processor with the VRM chip my computer beeps this is of one of two reasons.
a) the VRM chip was not completely inserted as when I put it in one side of it goes in perfectly while the otherside goes in about 90% of the way (I think the flipper that locks it place is messing with it?)
b) I have 4 ram slots, 2 from bottom up in a row have 512mb ram while the other slots are empty. I have no clue if this is true but I've heard that the other slots may need ram as well for the 2nd cpu?
(a) seems to more realistic but if anyone knows I would appreciate the help. maybe I could test that out. As four the 4 core thing I think caligari has set ts7 for 2 cores at the time being until 4 in 1 core processors come out not sure? |
Post by Bobbins // Aug 31, 2006, 2:44am
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Bobbins
Total Posts: 506
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LightWorks and VRay are both multithreaded. It makes no difference if you have seperate discrete CPUs, a multi-core cpu or several multi-core CPUs. As long as the operating system is correctly scheduling threads to the CPUs/cores then LightWorks and VRay will make use of them. If they aren't then the problem will be at a lower level than trueSpace.
As for populating extra memory slots if extra CPUs are installed, I have never ever come across a system architecture that requires this and it would be a poor design that required it. Some systems require memory to be installed in banks - pairs (or multiples thereof) of memory modules and to populate the available slots in a certain order, but not to require additional memory modules if extra CPUs are installed. |
Post by Asem // Aug 31, 2006, 3:06am
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Asem
Total Posts: 255
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Thanks for the thought Bobbins. I'll try again this weekend hopefully I get it running. |
Post by Vizu // Aug 31, 2006, 3:20am
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Vizu
Total Posts: 628
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thanky to you both.
Than it will be a good idea to buy a dual Xeon core duo system to have 4 cores to accelerate the renderspeed. |
Post by Alien // Aug 31, 2006, 6:49pm
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Alien
Total Posts: 1231
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As for populating extra memory slots if extra CPUs are installed, I have never ever come across a system architecture that requires this and it would be a poor design that required it. Some systems require memory to be installed in banks - pairs (or multiples thereof) of memory modules and to populate the available slots in a certain order, but not to require additional memory modules if extra CPUs are installed.
Have a read of this (http://en.wikipedia.org/wiki/Non-Uniform_Memory_Access).
Asem: check mobo manual for any mention of NUMA [Non Uniform Memory Access]. If there is, then that would explain the need for extra RAM sticks. If so, the link I gave should give you a better idea of what it is, & why it's a Good Thing (tm). :)
Than it will be a good idea to buy a dual Xeon core duo system to have 4 cores to accelerate the renderspeed.
Would be an even better idea to get a dual dual-core Opteron system. :D
<edit>
As four the 4 core thing I think caligari has set ts7 for 2 cores at the time being until 4 in 1 core processors come out not sure?
AFAIK, Caligari's made it to make use of as many CPUs/cores as we can afford to buy. :)
</edit> |
Post by Bobbins // Aug 31, 2006, 9:04pm
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Bobbins
Total Posts: 506
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I'm familiar with NUMA from my years spent supporting MP Unix systems since NUMA is supported under software control of the OpSys. On those systems it made sense as they were virtualised and different CPUs were assigned to run different operating systems.
First time I've heard of it on PCs as apart from Windows Server 2K3 (which tS is not supported under) I wasn't aware that any other 32 bit operating system provided support for it (working support, that is - some of the 32bit Linux kernels supposedly support it but nobody seems to be able to get it working despite the claims!). |
Post by Alien // Sep 1, 2006, 2:05am
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Alien
Total Posts: 1231
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First time I've heard of it on PCs as apart from Windows Server 2K3 (which tS is not supported under)
Damn, there go my dreams of winning the lottery & having an 8 CPU/16 core workstation to run tS on. :( [I know of 16 CPU/32 core servers, but AFAIK none have a proper graphics card slot, just crappy on-board video]
I wasn't aware that any other 32 bit operating system provided support for it (working support, that is - some of the 32bit Linux kernels supposedly support it but nobody seems to be able to get it working despite the claims!).
IIRC, support was introduced with XP SP2. I've even seen articles that compared performance between NUMA-enabled apps & non-NUMA enabled... or was it 2 mobos, 1 with & 1 without... http://homepage.ntlworld.com/alien42/smilies/dunno.gif I forget. I do recall it being mentioned that support also had to be coded for in the app, which is why I've asked more than once about it since the relase of tS7, though haven't received an answer either way, so I'm assuming the answer's no. It's a pity, really, as apparently it's supposed to improve performance quite significantly. |
Post by Bobbins // Sep 1, 2006, 2:30am
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Bobbins
Total Posts: 506
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[I know of 16 CPU/32 core servers, but AFAIK none have a proper graphics card slot, just crappy on-board video]
I have access to 64 cpu servers. They'd make a nice render machine but you're right, you wouldn't want to model in tS on them!
IIRC, support was introduced with XP SP2. I've even seen articles that compared performance between NUMA-enabled apps & non-NUMA enabled... or was it 2 mobos, 1 with & 1 without... I do recall it being mentioned that support also had to be coded for in the app, which is why I've asked more than once about it since the relase of tS7, though haven't received an answer either way, so I'm assuming the answer's no. It's a pity, really, as apparently it's supposed to improve performance quite significantly.
Hmm, I'm probably wrong because I thought it was just the 64 bit variant of Win XP that introduced NUMA hooks in the API. You'd be right about the app having to be coded for NUMA in that case, though.
The performance aspects are - as always - open to benchmarking abuse. Many apps will see a performance hit under NUMA due to the overhead in keeping memory coherency. As for tS having support for NUMA, I'd have thought it's too niche and too time consuming for it to be worthwhile. It would be more beneficial for SMP support to be written into more parts of the program than just Player physics (and VRay/LightWorks, but they are 3rd party code anyway). |
Post by Alien // Sep 1, 2006, 3:18pm
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Alien
Total Posts: 1231
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I have access to 64 cpu servers. They'd make a nice render machine but you're right, you wouldn't want to model in tS on them!
http://homepage.ntlworld.com/alien42/smilies/drool.gif
The performance aspects are - as always - open to benchmarking abuse. Many apps will see a performance hit under NUMA due to the overhead in keeping memory coherency.
I'm not sure about that - I'm a bit hazy on the details, but I thought I remembered reading something about AMD having some sort of algorithm for that sort of thing, 1 which Intel doesn't use, & apparently 1 of the reasons why AMD multi cpu systems tend to outperform their Intel counterparts. It's been a while since I read a review of a board with NUMA, but I don't recall it causing any major performance hits. http://homepage.ntlworld.com/alien42/smilies/dunno.gif
Then again, I've gotten somewhat out of touch with some aspects of the hardware scene. :o For example, I've read in several places that whilst AMD still seems to hold the performance crown on multi-CPU systems, on a single CPU [dual core] system Intel may have closed the gap, or even gotten ahead. I'm a bit confused on this ATM, as the core name mentioned [Woodcrest] seems to be just for Xeon chips [according to Wikipedia it is, anyway], which are usually intended for multi-CPU systems, unless Intel has taken a leaf out of AMD's book & made a single-socket-only [like 100 series Opterons] version. :confused:
As for tS having support for NUMA, I'd have thought it's too niche and too time consuming for it to be worthwhile.
Sadly, I think you're right. Then again, having thought about it & reviewed the various options, I probably won't be getting a system that would have it anyway in the near future, so... http://homepage.ntlworld.com/alien42/smilies/dunno.gif
It would be more beneficial for SMP support to be written into more parts of the program than just Player physics (and VRay/LightWorks, but they are 3rd party code anyway).
Yeah, that would be nice. |
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