Seriously, if you really, truly need to be able to save your data for later analysis, QNX can be as simple or as complex as you require. (Geez, I'm beginning to sound like a shill for them, but really I'm just making a point.)

I will withhold comment about using the same device to analyze data as you use to collect that data, except to say that the former should be optimized for computing power, while the latter should be optimized for real-time response, and the two criteria are not the same.