Date: Nov 21, 2012 2:40 PM
Author: spasmous
Subject: 16 CPU 32Gb RAM machine running 6 instances of MATLAB

As per title, I have a non-parallelizable script (numeric, not much IO) running in 6 separate MATLAB instances on a 16 CPU Xeon E5630. I figured these instances would all run fast however if I fire up another MATLAB and run bench(3) it indicates my machine is running just slightly better than an Intel Atom. I don't mean the graphics - FFTs, LU, sparse, etc. all are reporting poor numbers.

The RAM appears to be adequate (see output of "top" below) and overall CPU is at 39% utilization. There's nothing else heavy running on the machine. Maybe I have misunderstood how multi-core machines work!?

top - 11:20:58 up 56 days, 4:40, 2 users, load average: 17.08, 18.69, 19.10
Tasks: 349 total, 2 running, 347 sleeping, 0 stopped, 0 zombie
Cpu(s): 39.7%us, 28.7%sy, 0.0%ni, 31.6%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 33554432k total, 30417452k used, 3136980k free, 765416k buffers
Swap: 68059128k total, 368k used, 68058760k free, 16076936k cached

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
16773 matlab 20 0 3189m 2.2g 66m S 254.9 6.9 247:05.92 MATLAB
16905 matlab 21 0 3528m 2.5g 66m S 228.4 7.7 252:18.63 MATLAB
16610 matlab 21 0 2689m 1.7g 66m S 194.6 5.4 2817:41 MATLAB
22200 matlab 18 0 3234m 2.2g 66m S 170.7 7.0 247:24.46 MATLAB
16403 matlab 21 0 2460m 1.5g 66m S 154.2 4.6 2856:46 MATLAB
22426 matlab 25 0 1354m 518m 68m S 96.8 1.6 99:31.28 MATLAB
...