Some (not necessarily all) 2.5" portable HDDs have the USB port integrated right into the PCB, so there's no standard SATA to connect to. Also, generally, the price to capacity just isn't there to warrant it. Usually the 3.5" (larger) drives are where the incentive to shuck comes in. (Even then, IIRC the 6TB WDs are SMR Blues internally; would recommend 8TB and up for CMR higher-performance drives).
12 minutes ago, RJ45-Dude said:
Also, when watching tutorials on how to shuck hard drives, I learned that there is a pin on the hard drive itself you must cover up, as this pin controls the hard drive's power. However, in the tutorial, the hard drive had a button, while my hard drive (listed above) does not. Do I still have to cover up that pin?
This is the PWDIS pin, which is technically part of the newest ATX power standard. It uses the 3.3V rail pulled low to start the drive spinning. The downside being that most (all?) PSUs out there today still provide 3.3V over SATA power, and hence will hold the drive spun-down if it isn't fixed. Furthermore, this feature's presence varies from model to model and even drive to drive inside a specific model (call them sub-models). The safest way is to just make sure you don't feed 3.3V to and drive by either taping over the pins or removing the wire from the connector (if it happens to be one of the modular ones), but it isn't always strictly necessary.
In regards to this button: I'm not aware of any internal HDDs that have any form of user interface like that. They're all just plug and go as far as I'm aware.
Bonus tidbit: the PWDIS actually has a use in server-space (where a lot of the excess drives funneled into the external market come from), so that the system can stagger the spin-up of all the drives in the case of a 24 drive disk shelf, etc., and not overload the PSU.