Satoshi wrote:I know this is not the place to ask, but wouldn't a shared folder in a PC be the same as NAS, performance-wise?
That is a very loaded question.
If you're talking about a shared folder on the machine being described here, then there's just about nothing that could be slower. Using it in conjunction with modern home hardware will inevitably slow everyone down, not least of which being that most home hardware has a gigabit ethernet card and/or wireless N. A couple years back, simply hooking that up to a network caused the entire network to slow down to match the slowest component. Thank God for switches! And frankly I've been suspicions of some older so-called switches too, I suspect they were re-badged hubs.
NAS can be an architecture optimized for file sharing, and if you're dealing with something for a medium or large business then you're dealing with a lot of money aimed at really good throughput, hooked up to gigabit networking and possibly able to saturate the network interface.
Likewise, SAN in an enterprise setting generally uses an optical interface and can have throughputs which are similar to or larger than the disk interface in your computer (SATA, etc), and often the system boots from that. You get centralized management of storage, on-the-fly changes to partition sizes, easy backups and lots of other neat things.
If you have all-new equipment you can get a lot of performance for not much money. If you have new gear and an old switch/cable modem/wireless hub, then upgrading it can cause a significant boost to your whole network. I know this from experience, I used an old cable modem with my current network and never got anywhere near the performance they advertised. After I upgraded the modem I was getting burst speeds over their specs.