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World Community Grid Forums
Category: Retired Forums
Forum: UD Windows Agent Support [Read Only]
Thread: Running client on AMD A64 X2 |
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Thread Status: Active Total posts in this thread: 20
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Former Member
Cruncher Joined: May 22, 2018 Post Count: 0 Status: Offline |
Run as many copies of the Linux Agent as you want. My caution is about the Windows Agent, which is not programmed for multi-threading. Naturally, you can run several different programs at the same time on a multi-processor system in Windows XP. It is just that I think that there should be no more than one copy of the Windows Agent UD.exe running. I have put in a request for Rick Alther to give his opinion on this.
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Former Member
Cruncher Joined: May 22, 2018 Post Count: 0 Status: Offline |
Ok, i see what you're trying to say. The rosetta app may be run with as many instances as wanted but it's the UD.exe app that's causing the problems. If you use a tool like UDmon, does it open more then 1 time the UD app?
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Former Member
Cruncher Joined: May 22, 2018 Post Count: 0 Status: Offline |
I am not a qualified expert, but I will give a loud-mouthed ignorant opinion anyway. UDmon is OK. The problem is that UD.exe uses one or more global synchronization variables to keep track of where things are, so 2 instances of UD.exe, running 2 instances of Rosetta on different work units, can run into trouble if they need to use the value in the global variable. Writing to the variable is fine. But if they need to read it (where to start after a reboot comes to mind, though that is probably too simple to be true) then something will go wrong with one of the work units. It may not cause any trouble obvious to the user, but it will be obvious during validation once it is returned to the server.
As vaio pointed out, if you want to keep 2 processors busy on distributed computing projects in the same system it makes sense to run 2 different programs. Double your fun by following 2 different projects. Keep in mind, I don't really know what I am talking about. I just read explanations given by those who do - - and then I try to fill in the blanks to understand their explanations. I may be totally wrong. Stay skeptical and keep an open mind. mycrofth |
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Frood_1
Cruncher Joined: Nov 3, 2005 Post Count: 7 Status: Offline Project Badges: 
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Any word from Rick?
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Viktors
Former World Community Grid Tech Joined: Sep 20, 2004 Post Count: 653 Status: Offline Project Badges: 
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I don't have a processor-software configuration like you have to test this. However, from everything I know, the Windows agent is not designed to support this.
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Alther
Former World Community Grid Tech United States of America Joined: Sep 30, 2004 Post Count: 414 Status: Offline Project Badges: 
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Actually, you can under Windows XP, but it's probably unsupported. I have a dual AMD MP system running two instances just fine for over a month. The way to set it up is to create two user accounts, install the agent twice into two different directories, and set one of the agents to run in NT Compatability mode. You can find full details of this procedure at http://forum.grid.org/phpBB/viewtopic.php?t=4688&start=0 First thing to note is that the referenced thread is 4 years old and refers to an older version of the agent (2.0 and 2.1 specifically). Apparently, starting with version 2.1, they explicitly check for another instance of UD.exe running. While I'm not 100% positive how they do this, my guess is they set up a named kernel object. If it exists, another instance is running. If this is the case, there is no way to get two instances of UD running without using VMWare (or VMWare-like application). I followed the instructions in the referenced thread and was unable to get two instances running: 2 users, 2 installs, set compatibility mode - the Agent still detected another instance was running. If you got this to actually work, I'd be interested in the details because the 4 year old instructions no longer currently work. Finally, even if you do get it to work, there's no guarantee that the results produced are valid. The existing agent wasn't developed with SMP in mind and so there are likely race conditions and contention issues that could corrupt the results. I know the graphics use a named kernel object, so the graphics would either not work or have the potential to be corrupt. So why take that chance? We're all here to help solve a bigger problem, so why waste your CPU time send back corrupt results? Bottom line: don't try to run multiple instances of the agent on an SMP (or dual-core) machine. It's completely unsupported and even if you get it to work, there's no guarantee the results would be valid.
Rick Alther
Former World Community Grid Developer |
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Former Member
Cruncher Joined: May 22, 2018 Post Count: 0 Status: Offline |
Rick,
This does work under the current version of the client (3.0). The trick is to kick off the first (normal) agent before the one set in compatability mode. If you can't start the second one then it is because of a problem setting compatability mode (usually). As to corruption - agreed there would be no point doing this if there is a chance of returning bad results. Can you guys check to see if any of my systems have been throwing bad ones back, specifically HAL and HAL2 (HAL2 is the one set to compatability mode). Actually, it's probably not woth the time - I'm sure you'll have the boinc windows client out in a few months  |
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Former Member
Cruncher Joined: May 22, 2018 Post Count: 0 Status: Offline |
Is there also a 64-bit version of this for Windows XP x64 an 64-bit CPUs? I have to think for scientific computations, the extra native precision (and twice the accessible registers) would help a lot.
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Former Member
Cruncher Joined: May 22, 2018 Post Count: 0 Status: Offline |
Hello dmilford,
No. At the moment we do not have a 64-bit version. Anyway, in most scientific programs precision is usually dominated by the algorithm, which decides how many terms to include in an expression to achieve the required delta (error). The error caused by limited precision (epsilon) is normally much smaller than delta. |
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Former Member
Cruncher Joined: May 22, 2018 Post Count: 0 Status: Offline |
Morning Leon_R
As you may have seen in other threads, you can use the windows version of BOINC, which you can download directly from the BOINC website. One of the good things is it allows duel core PCs to crunch two work units at once. You might want to give this a go |
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