Bandwidth testing

So I hope someone can help me here I have looked all over and could not find a very good answer to this.

I have 2 RB1100 connected to each other with cat6.

I do a UDP BW test from one to the other and then get up to about 900 meg.

I do a tcp test between the two I get 377meg one way or 277meg x 277meg.
The cpu is only running at about 60% during this test no maxing out.

I know there is a lot of behind the scenes protocol stuff going on that put overhead on. However what should I expect to see with the above test? I would think this is about a clean of a test as you can get.

Just an updated I upgraded to the latest FW and I am now getting 800 meg speed tests much better.