why is this supposed to be much slower in a7 than with other engines? the additional views have to be rendered there too?
performance still is ok with 4 shadow views and a 100000 poly scene on my slow gf6600 (no gt). i don't do any filtering yet though.

so it could get quite slow at the end but games with shadow mapping (like the crysis demo with medium detail) run with about 5 - 10fps at 800x600 on my pc. you need a fast pc for such things.
pssm is running nicely but additional work is needed for reducing artifacts. i don't know much about the different shadow filtering methods and so on so it will take me a while to figure this out.