It's refering to the write speed of the drive the diode came from. eg: the "8x" diode was taken from an 8x Blu-ray burner drive, Usually the Pioneer BDR-203, or the LG models.
the 4x,6x,8x, and 12x all refer to blu-ray diodes.
Well... basically the write speed is sort of a way of determining the efficiency.. The higher the number usually the higher the power. The faster the write speed the faster a diode can write data to a disc. Lets take the PHR for example... It can write on a disc at Y speed. A 4x diode can write a disc at 4 x Y speed... meaning its 4 times faster, then a 6x diode can write at 6 x Y speed.. meaning its 6 times faster. Now to write at these speeds you must produce more power to compensate for faster writing speeds.... but it is not linear and in no way is a 6x diode 6 times as powerful. So 6x, 8x, 12x or what ever determines the write speed of a drive.
Hope that helped! -Adrian
Well that definitely was alot of good information. So if some says "8x 240mw kryton host" is the "8x" part necessary if the "240mw" is given?
And are 12x's on the verge of becoming affordable? If so is there much point to buying a 8x now if 12x's are soon to be released or w/e.
of course it's necessary, by saying 240mW 8x, for instance, you know that you can make it more powerful if you want since it's set to low power now. If I don't say 8x or 6x or the diode type it could be a GGW (6x) diode at max power. This would be worse because the diode life would be much lower compared to a 8x at the same level.
This numbers shows the speed the diode was meant to work. Then there are differences. the bests 6x burners feature a GGW which is in fact better than the SF-AW210 many other writers have. So although this number is a good indicator, not only this number counts
I hope that helped
Edit: I just saw marcuss answered some seconds before me. He's completly right. maybe not 300mW but yes, there could be some confusion