I have ~8 systems all running gigabit network cards over cat 6 switched by a linksys SR2016 gigabit switch and I don't think I'm getting anything close to full speed. scp transfers start out at about 22MB/s and eventually degrade to <10MB/s. smb transfers to the file server don't seem to go much faster.
Is that what I should be seeing, or should I start looking for problems? I don't think I'm getting bogged down by cpu as soem of the machines are pretty new.
Any thoughts? Where do I start looking for bottlenecks in a 1 hope transfer?

This has been asked several times, so you might want to spend some time searching for previous discussions. There are several potential bottlenecks:

- Are you using jumbo frames? Are they supported by your router and switch?
- The maximum sustained throughput of a typical hard drive is about 50MB/sec. Do you have the disk subsystem behind the gigabit NIC to support high sustained throughput?
- Have you researched the NICs and switch for known issues?
- Do you know the cabling was installed properly? Kinked cables must be replaced, not straightened. Cat 5E and above have special handling requirement for minimum bend radius and pull force. If the cables have been damaged, the error rate will go up, increasing retransmits and reducing throughput.
- Are you sure the CPU on either side of the transmission is not topping out? Scp adds encryption processing overhead; are you (or your distribution) using the high performance SSH patches?