Summary: I am multiplying 2 matrices in SciDB. Previously I recorded the calculation ran in 5 hours, but now I am observing / estimating it to run in 33 hours. This post is a description of my investigation and my attempt to speed up the calculation by reconfiguring SciDB to use more processors, and ultimately running the calculation piecemeal so I could monitor its progress.

Update: Using a system with 4 worker instances instead of 1 decreased the time by approximately a factor of 3.

Further Update: adding the specifier 'dense' to the multiply command increased the speed further by a factor of 1.5

#### Background

I have 2 matrices in SciDB that I want to multiply:particleStem_3 is 873637 x 42315

eigVect_3 is 42315 x 100

schema:

[("particleStem_3<count:double> [stem=0:873636,20,0,particle=0:42314,42315,0]")]

[("eigVect_3<value:double> [particle=0:42314,42315,0,eig=0:99,20,0]")]