What is MVS? How does it affect my printing?

[Demosth]

The hot-end maximum volumetric rate is the hard fast limit of a 3D FDM printer's capabilities. 

The hot end installed on a 3D printer can only melt and deliver a maximum filament flow in an amount of time. This extruding capacity is measured in cubic millimeters per second, or mm3/s, called Maximum Volumetric Speed (MVS).

Max.VolumetricRate = Layer Height x Extrusion Width x Speed

This implies that as we increment either Extrusion Width or Layer Height, speeds must be lowered to remain under a target MVS value. This doesn't mean that prints will be any slower – we are actually moving a similar filament length. However, the moving speed of the nozzle should be kept low enough to keep a safe MVS. 

Suppose your MVS is too high, and you attempt to move filament through the hotend any quicker. In that case, you're probably going to experience skips as the extruder can't push through the unmelted filament through the nozzle. This form of under extrusion is probably going to show on large surfaces and walls. Getting too ambitious and a stop up in the hotend or jam in the extruder is probable.