atomic add for GTS 8800?

I need to share an int between all blocks and my card is GTS 8800, so is there atomic add for GTS 8800? If yes, will it be a huge hit to performance using atomic add?

thanks

The old 8800 GTS with 320 or 640 MB of memory does not support atomic operations. The new 8800 GTS 512 MB does support atomic operations.

That means it is impossible to have global integer shared within blocks?

Correct. You will need to design your algorithm to avoid communication between blocks. There are a number of ways to eliminate the use of atomic operations in parallel algorithms, depending on the problem you are trying to solve.