s870 driver versions for CUDA 2.x

What version of Cuda are used to support an s870? From the download page it looks like the last driver was
“NVIDIA Driver for Linux with CUDA (171.05) specifically for Tesla S870 1U System”

This implies that 2.0 cannot be used?

Yes, you can use 2.x on S870, just pick up the right driver. The one for the S1070 will work.