Minimum size of SSD for Windows 10?

Solution
You need to allow for the fact that even if you choose to install applications on a separate storage drive, some app data will still (of necessity) automatically get written to the drive where Windows is installed, then there's those seemingly endless Windows updates from Microsoft which have to be on the same drive as Windows.

So realistically you should aim for the highest capacity SSD you can comfortable afford, not choose one on the basis of "the lowest capacity you can get away with".
You need to allow for the fact that even if you choose to install applications on a separate storage drive, some app data will still (of necessity) automatically get written to the drive where Windows is installed, then there's those seemingly endless Windows updates from Microsoft which have to be on the same drive as Windows.

So realistically you should aim for the highest capacity SSD you can comfortable afford, not choose one on the basis of "the lowest capacity you can get away with".
 
Solution


1. Having it be "just Windows" is throwing away 1/2 the functionality of having an SSD. You want your applications on it as well, to benefit from that speed.

2. At todays prices, the only thing that makes sense is a 250GB or larger.

3. It's getting hard to even find a 64GB drive from any reliable brand.