We also created an Iometer test by measuring typical file IO requests using Microsoft's Sysinternals Disk Monitor and then selecting the top seven I/O sizes and request types, read or write, and adding them to a profile (the Iometer configuration file is here:
The tests results were substantially lower than with the packaged tests, which is not shocking by any stretch considering most typical disk activity is composed of reading and writing relatively small files that are not stored sequentially on the drives. The i4x-200d does support TCP window scaling, which means TCP file transfers like FTP can be blazingly fast on the LAN and faster on the WAN than what you are used to with FTP.
The 32 KB sequential read and write performance tests show high performance that we'd expect with sequential reads. This highlights the best performance scenario for the NAS since the heads don't have to move far to continue to read data. The Laptop simulation, with 50 percent of reads and writes being random, forced the drives to move their heads to continue to read and write data, which resulted in lower throughput, fewer IOPS and higher average response times. The simulation results may be more indicative of what you might actually see in real use per client. Frankly, during months of use as our primary NAS, the ix4-200d performed well and we hardly noticed any delay in moving files to and from the NAS or when opening files remotely.
The ix4-200d is a VMware vSphere certified NAS using iSCSI and NFS, but we really wouldn't recommend the device for production image hosting, mainly because the ix4-200d doesn't have redundant power supplies. It would be a good fit for vSphere development environment where uptime and usability were important but down time could be tolerated.
We did like the built in BitTorrent support, though that is more a nerd feature than an SMB offering. The ix4-200d can set-up BitTorrent downloads via a URL or a tracker on the ix4-200d and it will download the files. I downloaded Fedora 11 and Fedora 12 DVDs without taking up space on my office computer. The ix4-200d does also has power management features such as dimming the bright blue LED panel and powering down the disks while idle.