HPC Multithreading
Turned off odd numbered cores on all 64 nodes of the HPC on Friday afternoon.
Principle Investigator emails me on Sunday morning telling me everything runs 42% slower.
I proceed to turn all the cores back on (I’ve got zero political leverage here).
Need to look into why; possible reasons:
1. I turned off hard-cores instead of soft-cores (very possible that it’s not as simple as turning off the odd-numbered cores)
2. His output reported an increase in the cputime … but that shows *more* work done in proportionally equal more time. :/ (—-PEBKAC?—- — no, because other users apparently are having the same problems. damn)
3. HT is good, don’t play with dials. (the only winning move is not to play, again)
