I have an Asus Sabertooth X79.

I often get corrupted files. I checked the RAM, but memtest finds no errors. To avoid the possibility of disk errors, I tried copying the files to tmpfs.

If I copy from the network, I get md5sum mismatches about once every 10 times using a 6Gb file. Copying from RAM to RAM, I didn't get mismatches.

I get a very high number of errors in ifconfig (compared to others PCs I just took as reference, which have 0 with much more traffic). Here is an example

RX packets:13972848 errors:200 dropped:0 overruns:0 frame:101

The motherboard is new, but do you think there're some problems with it? What could I use to test the (integrated) network adapter? What else do you think I should double check?

--edit--

I tried another NIC, it gives a lot of Corrupted MAC on Input. Disconnecting: Packet corrupt lost connection. I noticed that another PC downloads at 11.1MB/s without problems. This pc at 66.0 MB/s. Is there any way to try to limit the speed?