Rybka - Shredder, Olympiad final , Nice game

[Gian-Carlo Pascutto]

You can put the cluster machines in racks...

[M ANSARI]

I think it is difficult to overclock racks. You could probably come up with much cheaper overclocked quads that will give dramatically better performance. I am curious to what type of clustering setup was used for DS. Is it similar to master and slaves by Rybka or is it using a different method.

[Gian-Carlo Pascutto]

I posted some technical details of my approach in another thread here:

http://talkchess.com/forum/viewtopic.php?t=26945

Edit: Hmm, ok this doesn't really describe what I'm currently doing. But it's a good read about relevant issues anyway.

Very very basic description: when the engine is loaded in the GUI it starts a TCP server. Client nodes connect to this. During the search the TCP server sends out work packets to the clients. The clients do search work and send back the results.

[krazyken]

When you say "Cluster" are you referring to a "multi-core" CPU?!

A cluster is several machines connected together via a network. Deep Sjeng can use them together to increase its strength. So if you have 2 quads, Deep Sjeng can use them as if they were an 8 core machine.

Hi, why not just use racks?

What would be the advantage of clusters over racks?

a rack is a piece of hardware to hold stuff. It does not have a CPU and would play chess very poorly. Now if you had a rack of interconnected computers you could call it a cluster, and you could convince it to play chess with a bit of effort.

[Zach Wegner]

I think it is difficult to overclock racks. You could probably come up with much cheaper overclocked quads that will give dramatically better performance. I am curious to what type of clustering setup was used for DS. Is it similar to master and slaves by Rybka or is it using a different method.

There's not much difference for racks. You can still overclock them, but I don't want to do that anyway. Price is a big concern, I don't want them eating up power, so I don't even have hard drives on my nodes. The cases are a bit more expensive though. The reason I went with rackmounts is space. I don't have room for 6 or so full size cases. Rackmount also looks cooler, and allow me to use shorter network cables.

[M ANSARI]

Well I actually did make a "farm" of computers using quads a while back. I guess it would be similar to a rack since they did not use cases and were stacked on top of each other for one box. I had 4 computers, basically 4 motherboards on top of each other complete with power supply, memory and vga cards with a hard disk. I had a system with switches that allowed me to use only one monitor and one mouse for all the motherboards.

I used it mostly to run different tournies testing different lines or settings for Rybka. It would have been very simple to have each motherboard asssigned an IP address using Chess client software and I guess it would take one more step further to get a cluster running (proper software).

[Zach Wegner]

Well I actually did make a "farm" of computers using quads a while back. I guess it would be similar to a rack since they did not use cases and were stacked on top of each other for one box. I had 4 computers, basically 4 motherboards on top of each other complete with power supply, memory and vga cards with a hard disk. I had a system with switches that allowed me to use only one monitor and one mouse for all the motherboards.

How big was this box? And how did you mount it inside? Seems pretty cool though.

I used it mostly to run different tournies testing different lines or settings for Rybka. It would have been very simple to have each motherboard asssigned an IP address using Chess client software and I guess it would take one more step further to get a cluster running (proper software).

If you plug the computers into a router, then they'll get IP addresses automatically. That part is simple really. I have it set up even without monitors or keyboards though--I connect via ssh from my "normal" quad. Add a bunch of scripts to manage all the cluster nodes and things get much more fun

[M ANSARI]

Actually it was simply made from plywood with the motherboards stacked on top of each other. My plan was to go a little more and provide watercooling from one waterchiller that would provide watercooling for all the CPU's. I found a 2 TN waterchiller for very cheap (locally here they are very common) and it would be simple to route chilled water to all CPU's in the farm. The delta curve for chilled water is great for CPU cooling, especially Quadcores that can put out a lot of heat continuously. You would then have an IP address for each motherboard and load all that power from a quiet remote location in the house. Obviously in my case the probing of moves is done manually, but someone should be able to write a script or something better to automate all that.