This paper establishes the close relation that exists between the Fano noise suppression factor F and the Gm/ID FoM showing that F is proportional to the product of the thermal noise excess factor γn and the normalized Gm/ID function. Taking advantage of the EKV model formulation of the normalized Gm/ID and γn in terms of the inversion coefficient IC, a simple expression of F versus IC for long and short channel transistors is derived. The proposed model of F versus IC for short-channel devices is validated against measurement from various CMOS technologies. Additional measurements of Gm/ID performed on FDSOI devices down to cryogenic temperatures show that it is a universal FoM almost independent of temperature. Since F is proportional to Gm/ID, F should also be almost temperature independent. The proposed model constitutes a good starting point for having a model of the MOSFET white noise that is valid in all regions of operation and down to cryogenic temperatures.