Re: Compiled 3.8.0 from source on Ubuntu 12.10 slower than 3.6.3 from PPA

[Mike Miller]

On Tue, Mar 11, 2014 at 08:10:08 -0700, Aielyn wrote:
> [...3.8.0 is slower than 3.6.4...]
> Is there reason to think that
> the problem might be a performance regression in 3.8, or is this definitely
> a matter of compiler settings?

Both are certainly possible. The best way to get help is to share some
sample code that demonstrates the performance difference you are
seeing with the kinds of functions you are using so that others can
try it on other systems.

If you can share your code, or some representative code that does
similar operations and shows the same performance penalty, that might
help others help you. As a start, I tried your simple one-liner for
loop on one machine and I got a very slight (less than 5%) improvement
in 3.8.0 over 3.6.4, even with JIT disabled, both self-compiled and
using reference BLAS and LAPACK. So with that small sample, I'm not
seeing a regression.

You might also try compiling 3.6.4 the same way you are compiling
3.8.0 as another point of comparison.

-- 
mike