@adolescent:
The system was fine, the nfs-client is running at priority 0, so if something else needs cpu, it will share it fairly with the nfs client.
It is like using the ide-interface of an A600/A1200/A4000 or any other non-dma device. It will chew as much cpu as it can if it is not waiting for something, but it wont kill the system, only lessen the performance of the other applications (more apps sharing the cpu).
The reason smbfs isnt taking 100% cpu is because it partly is waiting for something to happen which in this case is the network.
Also, dont worry about the buffers with ch_nfsc, it is just the way the nfs-client is implemented. It most likely has an internal cache of some kind, even if it doesnt show it nor let you change its size, else small reads/writes would kill its performance completely, which doesnt seem to be the case.
/Patrik