Utilizing Intel's I340 server NIC on one end, and a Realtek on the other, a transfer from SSD to SSD (Corsair F160 to Corsair F160) proved to be about 111MB/s for a solid file, and 56.75MB/s for a folder, which consisted of 6,353 files of varying sizes. At around 111MB/s, we found our network to be pretty-well maxed-out, even with the Intel server card involved (and for what it's worth, we found pretty much the same in Linux, except it was 1MB/s slower on average).
Slow computer got you down? Maybe a hardware upgrade should be in your cards, if so this guide to the Fundamentals of Upgrading a PC is an invaluable read. PCSTATS Tips