Welcome to Fractal Forums

Fractal Software => UltraFractal => Topic started by: ker2x on September 19, 2010, 02:42:57 PM




Title: cluster scalability problems (24 + 6 cores)
Post by: ker2x on September 19, 2010, 02:42:57 PM
Hi !
I'm running ultrafractal client on my local computer (4 cores) + connected to a 24 cores server (running wine) + a 6 core server (running wine).
i launched 24 + 6 nodes from my client, and a 10000x7000 3D Rendering, the cpu usage rarely go over 200% usage on the 24 cores server instead of close to 2400%

What's happening ?

(fiber optic network on both side, the ping is ~20ms (from toulouse to paris))



Title: Re: cluster scalability problems (24 + 6 cores)
Post by: bib on September 19, 2010, 03:16:03 PM
Although I don't have access to such a setup, I have also seen that behaviour on my local machines, depending on the fractal formula. Have you tested it for example with a basic Mandelbrot zoom?


Title: Re: cluster scalability problems (24 + 6 cores)
Post by: ker2x on September 19, 2010, 04:21:09 PM
i found that the nodes are computing very tiny block. usually 1 or 2s of computing per block, which is really too small.
I decided to run UF5 client directly on the 24 cores monster and forget about remote nodes. Much faster and 2100% CPU \o/

10000x7000 mandelbox in progress... 22h remaining.
Next i'll try with mandelbulber 3D, if possible.


Title: Re: cluster scalability problems (24 + 6 cores)
Post by: ker2x on September 19, 2010, 04:49:38 PM
i will be able to play with 216 cores (yes, 9x24cores) for a few days ... too bad it won't scale :(

edit : just for the fun of it :


Cpu0  :100.0%us,  0.0%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu1  :100.0%us,  0.0%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu2  :100.0%us,  0.0%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu3  :100.0%us,  0.0%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu4  : 99.7%us,  0.3%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu5  :100.0%us,  0.0%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu6  :100.0%us,  0.0%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu7  :100.0%us,  0.0%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu8  :100.0%us,  0.0%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu9  : 99.7%us,  0.0%sy,  0.0%ni,  0.3%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu10 :100.0%us,  0.0%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu11 :100.0%us,  0.0%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu12 : 97.3%us,  0.0%sy,  0.0%ni,  2.7%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu13 :100.0%us,  0.0%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu14 :100.0%us,  0.0%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu15 :100.0%us,  0.0%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu16 :  0.0%us,  0.0%sy,  0.0%ni,100.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu17 :100.0%us,  0.0%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu18 :  0.0%us,  0.0%sy,  0.0%ni,100.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu19 :100.0%us,  0.0%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu20 :100.0%us,  0.0%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu21 :100.0%us,  0.0%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu22 :  0.6%us,  0.6%sy,  0.0%ni, 98.8%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu23 :100.0%us,  0.0%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st


Title: Re: cluster scalability problems (24 + 6 cores)
Post by: David Makin on September 19, 2010, 08:24:49 PM
I think UF5's network capabilities were designed with a local network in mind, not going via the internet - hence the size of blocks per thread used are small, this is fine over a local network but subject to relatively large delays over the internet.
Also I seem to recall that network rendering will proceed at the rate of the *slowest* machine on the network - so if one computer has 24 cores and another networked has just 6 then it's likely that only 6 will be used on the 24 core system, or if I networked my P4HT with a quadcore system even locally then the best speed I would get is double the speed of my P4HT which is actually slower than a quadcore on its own.


Title: Re: cluster scalability problems (24 + 6 cores)
Post by: ker2x on September 19, 2010, 11:22:49 PM
I think UF5's network capabilities were designed with a local network in mind, not going via the internet - hence the size of blocks per thread used are small, this is fine over a local network but subject to relatively large delays over the internet.
Also I seem to recall that network rendering will proceed at the rate of the *slowest* machine on the network - so if one computer has 24 cores and another networked has just 6 then it's likely that only 6 will be used on the 24 core system, or if I networked my P4HT with a quadcore system even locally then the best speed I would get is double the speed of my P4HT which is actually slower than a quadcore on its own.

Mmm, i will try then.
The 9x24 cores will be in the same datacenter with a very good network :)