Also, what made the biggest improvement for me was in the security services, there is a security services setting, change that to performance optimized instead of maximum security. Also, clean up any unneeded nat policies and consolidate any firewall policies. What i did was to turn off any security services on zones that they are not needed, like the LAN zone. There are some settings you can do to help. I will be looking to upgrade to an NSA-220 or 240 soon. In looking in the specs, I found out that this model just will not handle that amount of throughput with all the security services, an example is that the UTM service will only handle up to 50mb/s throughput, and that is SonicWall specs so you know that is lower in real life. Our throughput was no where near the 50mb. We went from a 10mb DSL connection to a 50mb broadband connection.
I have a tz-210 and ran into the same issue.
