Pentium J2900 is basically 11+ year old quad core Atom at modest clocks so don't stress too much about trying to make it feel faster. If you have enough modules to get it to 8GB I'd say it's worth a ...
The thing about desktops vs NAS is the desktop always has higher specs and gives you more bang for buck. A $500 NAS gives you what - a Pentium/Celeron dual core with 4GB RAM? I don't think the extra ...