But what must i enter in the fields for "FlowControl", "AutoNeg", "Duplex" and "Speed" to set them?

I don't think that this will help, because a few hours ago i startet my restore again, this data will go with eth1 into the storage and runs with 70 MBit/s (from check_sys). In ESX i saw a speed of 8 MB/s. Then i started a IOMeter from my workstation which is connected to eth0 and got 30-35 MB/s but in this moment the speed in ESX goes down to 500 KB/s. Wehen i stop IOMeter the speed in ESX goes up again... But i will leave nothing untested.

The best will be when i can made a networking test, to see what performance i got when i made this on one NIC and then on two and final at all three NIC's.

Regards
Stefan