Does anyone know what is the difference between the above two (bulk) drives?
I will guess the obvious, the first should be 22x burner and the other a 24x.
This is strange as the IHAS122-14 is more expensive than the IHAS124-14. But if this is the difference should I also assume that they are using different chipsets?
I am not sure, but they could also be using different chipsets.
NO idea whay one is more expensive that the other, it might have something with availability.
There are to much models of the ihas 124 out there, maybe also of 122. More details needed to know what the difference is, Liteon uses letters after the 124-14 …
Unfortunately the letters are not advertised with the numbers so you never know what you will get when you buy.
These drives are both revisions of models E/EU/EUV differing by firmware/OEM version only.
EDIT: More likely F/FU these days, but the difference is still software.
I am wondering why they are making 24x and 22x drives if the hardware in these is the same.
Same reason they sell overclockable CPU’s at 3.00Ghz and 3.20Ghz, binning of chips (sometimes) and definitely product/price segmentation. I’d say its more of the latter in this case.
Yep. They also provide the DH-16AFSH, which is a slower iHAS124 F, for OEMs. Much like there was a DH-8B2SH, which was a detuned iHBS112. Same hardware, slightly different products.
Reach back far enough, you’ll see a few other 16x drives that were speed-reduced versions of 18x, 20x, 22x, or 24x models.
And there was also the minor differentiation way back with drives like the SOHW-1213S/1613S/1633S/1653S; though those models were more or less released sequentially to keep up with the spec wars, you could also find some of them on the market concurrently, when all could ultimately have been a 1653S.
1653S was the awfulst DVD-drive I´ve ever owned :\
I think the chipsets of optical drives can´t be compared with x86-CPUs. The speed-downgrades aren´t logical IMHO.
But I have a bunch of 24x-drives and only with a few media I can go higher than 16x, except the DVR-S20 which overspeeds also some Non-TY or MCC to 18x or 20x
So the PLDS dh16aesh is a liteon?
PLDS = Philips & Lite-On Digital Solutions Corporation (PLDS), so the answer should be easy 
Philips stopped manufacturing of ODD long time ago