I tend to keep it a few hours away from the workout period, just because it is an anti-oxidant. That said, I don't think it matters hugely. I am on 900mg a day and split that 200mg morning; 500mg at lunch; and 200mg at night.
Interestingly, a well known TV doctor was part of some research here in the UK which looked at turmeric supplementation. The upshot was that there was no change in gene expression with the placebo group or the turmeric supplementation group. However, the third group, which were to ingest raw turmeric anyway they wanted, had significant changes in gene expression.