Hi WD Community.
I want to use 2 identical hard drives in QNAP NAS!
Question! What is the difference between the two identical versions of RED PRO 10 TB, WD101KFBX and WD102KFBX? Both versions are on sale.
Thank you for quick answer.
I’ts look like WD102KFBX is a newer and unfortunately worse (in my opinion) version of the disk… because it’s probably not HelioSeal series now. According to datasheet, it is less energy efficient and louder. Due to lack of helium, it will probably runs hotter too. Is it faster than older version? …I can not confirm it because the older WD101KFBX (which I have personally) easily reaches 265MB/s in read/write. I haven’t seen newer version tests yet.
The most important question is… if it’s worse in almost every aspect, why it’s price are the same or even higher (at least that’s how it is in my country) than WD101KFBX? That is what we must ask WD.
Two years ago, when I bought WD101KFBX, I checked in internet before, to see if it wasn’t a SMR drive (it was starting somewhere at that time). I chose well, but as it turns out now… it’s a lot easier to make a serious mistake, because WD is hiding information. In my opinion SMR is only suitable for ColdStorage and difinately not for NAS, even those less loaded.
The effect is that I lost a lot of trust in WD because they started using such tricks!
Another result, less pleasant for WD, will be loss of customers and I think it has already begun.
WD101KFBX I can recommend with a clear conscience… WD102KFBX not necessarily.
Anyway … I hope You choose well and You’ll be as happy as I am. 
Sorry for bad english.
