[Radiance-general] Optimizing Radiance for cluster rendering

[Iebele]

Hi All, 

Nobody responded to the mail below yet. In the meanwhile I tried to build Radiance with Intels icc compiler. Binaries compiled with icc (many warnings) work for a simple scene, but fail when I render complex scenes (Segmentation fault). So I went back to gcc compiled binaries, but still I wonder if somebody can give me hints on what compiler to use, which flags, etc..

Support from the cluster engineers suggested I should make local copies of my files to the scratch discs of the nodes where I start Radiance processes. This, because otherwise networked i/o would slow down the process, and the cluster in general. Concerning the output of the rpict/ranimate process I understand what to do. But concerning the input files, I always thought that Radiance loads all input files (geometry, image patters etc) in memory only one time for each input file.  If the latter is true, I think it does not make much difference to load scene data from my home directory over the network, or first copy the input files (about 3 GB) to scratch disc and load them in rpict/ranimate thereafter.  The input files have to be copied over the network anyways. Or am I wrong here?  

Concerning the binaries, I have a question alike: would it be better to make a local install of the binaries for each node?   

Any hints are most appreciated

Iebele



oconv.c(322): (col. 5) remark: PARTIAL LOOP WAS VECTORIZED.



Op 7 apr. 2012, om 01:20 heeft Iebele het volgende geschreven:

> Hi group, 
> 
> I'm setting up Radiance on a computer cluster with lots of nodes. Tweeking gcc flags is not my best quality(understatement), so I bring it here. 
> Playing a bit with options which I found on Marc's benchmark page, I got rendering times per core over twice as long as on my 2.2 Ghz macbook. Doesn't make me happy :) 
> Below I've pasted the cpuinfo from a node on the cluster. Does anyone in the group has an idea what flags I should give to gcc to optimize Radiance? 
> The flags I've used so far - are:   -march=native -m64 -msse -msse2 -funroll-loops -ffast-math  -O3  -Dlinux -D_FILE_OFFSET_BITS=64
> 
> Cheers, 
> 
> iebele
> 
> 
> cat /proc/cpuinfo:
> 
> processor	: 7
> vendor_id	: GenuineIntel
> cpu family	: 6
> model		: 23
> model name	: Intel(R) Xeon(R) CPU           L5420  @ 2.50GHz
> stepping	: 10
> cpu MHz		: 2493.445
> cache size	: 6144 KB
> physical id	: 0
> siblings	: 4
> core id		: 2
> cpu cores	: 4
> apicid		: 2
> initial apicid	: 2
> fpu		: yes
> fpu_exception	: yes
> cpuid level	: 13
> wp		: yes
> flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 xsave lahf_lm tpr_shadow vnmi flexpriority
> bogomips	: 4987.90
> clflush size	: 64
> cache_alignment	: 64
> address sizes	: 38 bits physical, 48 bits virtual
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