I tell you something: having an Atom or a Nano processor won't influcence that much performance as you can with 1-2 GB RAM and a fast hard disk or SDD.
I personally consider current Intel Atom N270 and VIA Nano processors at the same performance level, little below Pentium M and far below Core 2 Duo processors.
I prepared a couple of charts showing the performance difference Atom/Nano vs Pentium M and Core 2 Duo processors.
The first chart shows SPECint_rate_base2006 and SPECfp_rate_base2006 for
- Intel Atom N270
- VIA Nano N2100
- Pentium M 780
- Core 2 Duo T7800
- Core 2 Duo T9500
The core efficiency can be also seen if you consider the benchmark figures divided by GHz and number of cores. This is what I show in next chart: Pentium M and especially Core 2 Duo are far more efficient than Atom and Nano. Of course we didn't expect something different since Atom and Nano are designed for low cost/low performance and especially low power designs.