Do you REALLY need a NAS? (Score 1)

It sounds to me like you need to better define the criteria which require a NAS. Whenever looking into new equipment it's always helpful to define the ideal situation in which your new equipment would function... for me based on what you mentioned I would say the ideal would be:

-0 wait time for transfer
-Portability of data

At no point did you mention other people needing the data while you're running the tests. Based on those criteria I would shy away from a NAS. Unless you're willing to shell out a grand for a Linux solution, a 1 TB external drive with an eSata connection will be ~$900 cheaper and possibly perform better to those criteria above. When you're not doing the testing you can simply plug it into an idle machine for people access the data over the network and to perform backups.

I'm a big fan of home-brewed Linux Raid NAS solutions, I setup and maintain a few myself for several different organizations and I regularly transfer 100+ gig dumps of files... however I would avoid doing all of this if I could. Keep it simple... it's much easier to just carry the data with you from machine to machine if your files are exceedingly large... after all HD's are cheap now-a-days.

On another note if you do insist on a NAS, one thing I've noticed is that Filesizes can easily affect transfer rates. The smaller the average filesize, the larger the individual overhead is in comparison to the file. In other words if you're transferring 100meg files and the overhead is a theoretical 1kb then the majority of time is spent moving the file but if you're transferring 1kb files and the overhead is still 1kb then you spend just as much time on the overhead as on the files themselves.

One trick I've learned to speed large transfers of small files along is to turn your files into a storage-level-compression tarball on the fly with a blowfish cipher and pipe the output over ssh to the other machine, where it is disassembled on the fly as well. This means that you're only transferring one file across the pipe and there is less overhead to the total transfer. This trick keeps the transfer rate on my machines steady at around 10-20mb/s as opposed to 6-7mb/s and those numbers are on a standard configuration with no special hd's or raid implemented. I can only expect the numbers to be better with raid. Just things to think about.