This is not surprising, transiesta is only parallelized across energy points. This means you probably have between 33 and 64 energy points on your contour.
2016-08-17 23:00 GMT+02:00 Yangchuan Li <[email protected]>: > Dear siesta users, > > I did a speed up test of transiesta (version 4.0 stable) on a cluster. I > run a job of 380 atoms with different number of cores. And here is the > result. The running time doesn't include tbtrans running. > cores Transiesta > 32 8h 19m 41s 557ms > 64 4h 18m 26s 283ms > 96 4h 20m 11s 997ms > 128 4h 18m 9s 189ms > 256 4h 18m 37s 196ms > 512 4h 19m 8s 984ms > > It seems strange because from 32 to 64 I got a perfect speed up, while > increase the cores from 64 doesn't give me anything. > So, why this happened and is there a way to speed up more? > Any comments will be appreciated. Thanks. > > Yangchuan > Graduate research assistant > ME | UT Austin > -- Kind regards Nick
