Ever wondered what the true print speed really is when you add in all of the factors. Found this great explination from Solidoodle forums http://www.soliforum.com/topic/9985/e3d-volcano-slicer-settings/page/2/
true print speed = feedrate * layer height * layer width
Print head types:
jhead = 100mm/sec * .3mm * .4mm = 12mm^3/sec
volcano = 25mm/sec * 1.2mm * .9mm = 27mm^3/sec
A Volcano is twice the speed of a standard j-head that printing at high speed. 1.75mm prints faster than 3mm when it comes to Volcano, confirmed by E3D.