gigabit network, 350mbit/s what is this rubbish?

[Rubberman]

Jumbo frames (not standard - don't always work) will greatly reduce the number of packets, hence the greater thruput. I don't know if you can enable them on your Linux system or not - I haven't tried it myself. However, I have a couple of NAS appliances that have an embedded Linux running them that does support jumbo frames, so in theory it is possible.

[Mad Professor]

I think my backup server is the problem it can receive 60% throughput but sending out is about 30%

Everything seems to be working now after I modify the sysctl.conf and enable jumbo frames and use 64K window sizes.

Definitely need to keep tweaking it.

Any suggestions?

[Rubberman]

Well, it sounds like you are doing the right things. I'm out of further ideas at the moment. Default speeds for gigabit connections have been adequate for my needs up to this point. I'd love to here what you find that works to maximize your thruput though, for future reference.

[b2bwild]

I think my backup server is the problem it can receive 60% throughput but sending out is about 30%

Everything seems to be working now after I modify the sysctl.conf and enable jumbo frames and use 64K window sizes.

Definitely need to keep tweaking it.

Any suggestions?

Well, at least you now have better results.
there are always bit limitations, I have not seen anyone with more than 850-900Mbit throughput on Gbit network.. for that you need some more firepower on your machine.

remember that every testing tool also have limitations.