With the introduction of bigger drives, does heat increase?
Heat generated by a drive depends on a number of factors. Those include number of platters, spindle speed and motor efficiency. Head movement and head actuator power consumption also generates heat. The electronics also plays a role but not just in the amount of heat it generates itself.
Increased capacity in itself does not generate more heat, unless it requires more platters. For example, an older generation 320GB drive may require 3 platters and a newer generation 500GB may require only two platters (due to increased data density.) The older 250GB drive would usually require more power and generate more heat. Withing a single generation of drives, extra capacity is usually obtained by adding more platters so the larger drive in that scenario would produce more heat. Faster spindle speeds also generate more heat. That is why new "green" drives have slower spindle speeds or variable spindle speeds.
Some newer drives have idle and sleep modes that stop the motor and/or put the electronics in standby (sleep) mode. Cache size and advanced caching algorithms also play a role in how much the read/write heads move and how much power the head actuator consumes. Almost all power consumed by a drive is converted into heat so a drive that consumes less power runs cooler. Some newer drives consume as little as 1/2 or 1/3 the power of previous models with almost as good performance. In an external case, the limiting factor in performance is usually the USB interface, so it is worthwhile to trade a little performance for power savings.
Thanks Scary Bob. I looked on WDs' website and all the info I could get was on wattage used per function(read/write etc). Nothing about heat generated per function. I suppose there is a formula to figure that out using wattage.
I went for performance and bought a HD enclosure with a fan/sata connection. My desktop has a 300gb Velociraptor inside and that comes with its own special heatsink enclosure.