Has anything changed in H15 regarding fluid sims? I am experiencing very slow simulation speeds. Also I was sure I could use my GPU on at least Flip sims.. Can't seem to find that check box - if it exists.

Any pointers on speed optimising is greatly appreciated.

Get more memory, get a SSD drive, get a faster CPU, the checkbox for turning on the GPU is in the solver under the advanced options.

Use a larger particle density for faster sims, the smaller the value, the longer the time.

There it was! Thanks. I have a pretty fast rig with all of the above mentioned. Now using 2 titanx cards it's a lot more fun.