The Mac Pro's Xeon processors generated much less heat than the previous dual-core G5s, so the size of the internal cooling devices were reduced significantly. This allowed the interior to be re-arranged, leaving more room at the top of the case and doubling the number of internal drive bays. This also allowed the elimination of the large clear plastic air deflector used as part of the cooling system in the Power Mac G5. Less heat also meant less air to move out of the case for cooling during normal operations; the Mac Pro was very quiet in normal operation, quieter than the much noisier Power Mac G5, and proved difficult to measure using common sound pressure level meters. The handle on and cooling air intake configuration of the front of the case has caused Macintosh enthusiasts to refer to the first generation as the "cheese grater" Mac Pro.