I’ve met the same issue.
Computer: Alienware m17x R3; Network card: Atheros Ar8151; AV: Avast Endpoint Protection Suite Plus.
Solution: It was quite enough to disable the “Largesend offload” option at the network adapter/properties/setup/special.
All the other options are not necessary to change.
Borisrd,
Thank you for your input. I spent all day trying to figure out why my NIC wouldn’t transfer over 1MB. Though it wasn’t hampering my online experience greatly, it was driving me nuts. The suggestion to disable “LargeSendOffload” did the trick.
Wow! Thanks so much. Just building up a new system and I ran into the same problem with an Atheros AR8161/8165 ethernet controller giving perfect download speeds but horrendously slow uploads. The simple step of switching off “Large Send Offload (IPv4)” to “Disabled” fixed it. I went from like 0.25-0.6 (!) Mbps to 3.5-4 where it should be.
I don’t even have Avast or anything of the sort even installed at the moment so it is something other than an Avast conflict issue alone.