Benefits of Gigabit

We have a couple of computers at work for doing video editing/rendering. Basically it gets edited on one and then sent over to another to be rendered. Before we started using them I decided to try hooking up gigabit ethernet between them so that transferring 6+ GB files wouldn't take so long. What I discovered, though, is that despite the network we can still only get about 13 MB/s transfer speed between the computers with those files.
Looking around for a bit, I realized that the real bottleneck here is the transfer speed of the hard drives. The most we could ever hope for, it seems, is about 50MB/s, which would still be nice and fast, but it doesn't ever really get up to that speed. And that is still certainly not near the potential of the network.
So what is the point of switching over to gigabit equipment at this point if transferring anything over the network is so limited by hard drive speeds? Is there some way around this to speed up transfers?

I definitely need to look into putting both computers into RAID. One of them is right now, but I have no idea about the other. And I didn't really think about having more than 2 computers trying to transfer something at the same time. Makes sense!

Alright after checking all the equipment (gigabit switches, CAT6 cable, and gigabit NICs) and confirming that both are connected at 1Gbps in the networking center, I ran some network benchmarking software between the two computers. With TCP and uniform packets I got ~220Mbps, with UDP it went up to ~500Mbps, and switching to variable packets it dropped closer to ~60Mbps.
So it looks like it should be capable of getting up to higher speeds, just not sure why it isn't. The big files being transferred are uncompressed AVIs, not sure what effect that would have on the transfer (variable or uniform packet sizes).