Well, I don't think Mesmerise was likely particularly well optimised for starters...
The only commonality between Mesmerise and Arc is the latency in getting data from capture->PS3. After that you have to suppose the processing will differ both in substance (I imagine Arc processing is simpler...) and in the level of optimisation applied. So that's why I think it's quite crude to try and use Mesmerise as a guide wrt potential Arc performance. I do hope they get the opportunity to measure latency directly at GDC though.
FWIW, Sony did kind of address difference between latency in Arc and 'previous camera work' on PS3 at last year's Develop.
The only commonality between Mesmerise and Arc is the latency in getting data from capture->PS3. After that you have to suppose the processing will differ both in substance (I imagine Arc processing is simpler...) and in the level of optimisation applied. So that's why I think it's quite crude to try and use Mesmerise as a guide wrt potential Arc performance. I do hope they get the opportunity to measure latency directly at GDC though.
FWIW, Sony did kind of address difference between latency in Arc and 'previous camera work' on PS3 at last year's Develop.