The software will run on a small Z3735F ATOM system such as the Quantum Byte Fanless Windows® Mini Desktop PC but only at low bandwidths (typically less than 1 MHz), anything higher can lock up the software. If you want a nice and nippy PC then the suggested minimum configuration is:
- 64-bit Windows 7, 8, 10 (10 is recommended)
- 4GB RAM (8GB is better)
- 128GB SSD Disk for Windows
- i5 4th generation or better, any CPU frequency (i3 if on a tight budget)
- (Optional) If you are buying a graphics card then NVIDIA is recommended with compute capability 3.0 or higher, for a list of NVIDIA GPUs: https://developer.nvidia.com/cuda-gpus (more about CUDA below)
CPUs such as the Core2Duo do not have the recent extension instruction sets and will not process high bandwidths efficiently. In its day the Core2DUO was an outstanding CPU. For information about extension sets see the diagnostics page.
NVIDIA and CUDA
When you use a higher bandwidth (~5 MHz or more) with increased waterfall resolution the processing demand will increase, specifically it is the FFT [wikipedia] processing load. Graphics cards are well suited to FFT processing as they are parallel processors.
If you have a NVIDIA graphics card with compute capability 3.0 (or higher) and support for unified memory (all newer cards support this) then the FFT processing can run on the NVIDIA card, thus freeing up CPU cycles for other activities. Also a graphics card card run the FFT processing at a higher resolution than supported on an Intel / AMD CPU core, for example when running the AirSpy at 10MHz bandwidth with x4 (or higher) resolution.
In addition offloading graphics processing to a graphics card can (not necessarily will) result in a faster, more fluid response, especially when using higher resolution displays such as 4k at a 60 Hz refresh rate.
At the time of writing (late May, 2016) a good price / performance card is the GTX 950. The minimum card is the GT 730.
Bottom line: only you can decide whether to buy a NVIDIA graphics card, it is advisable when buying a new computer, but can always be added later.