B-die can reach insane clockspeeds (4000 MHz+) while Hynix e-die is . . . well personally I've not heard of it going quite so high. And timings on the b-die can be tighter. People still swear by it since it's been a performance standard since 2016/2017 or so. It's time to move on though. E-die is cheaper and almost as good, and future RAM products will hit higher densities at "good enough" speeds. Eventually Samsung a-die may unseat b-die as the performance champ, but we'll see.
Going back to the topic . . . be aware that pushing RAM speeds higher on Matisse (such as a 3900x) stresses the I/O die more, which can have some deleterious effects on your clockspeed headroom, especially if you use static OC. It can also increase temps a wee bit.
Thanks! All good information. I was asking because I searched like crazy to find EXACTLY what I wanted, which was GSkill TridentZ Neo 3600mhz 2x16gb chips 3600C16D-GTZN. Most of what was out there on Black Friday was GTZNC, which is the Hynex. So I finally found my C16D-GTZN, but it was on Newegg, who I have ALWAYS had problems with, and as a result had not ordered anything from in more than three years. And this was like 1am on BF morning, and the prices had not changed yet. So I put it in my shopping cart, with the expectation of getting up early and seeing if there were price changes on it. But when I got up at 7:30am, they had ripped it out of my shopping cart, and sold out of it. This was the first time I had EVER had anything removed from my shopping cart. And I could have understood it, if it was over several days or a week. But this was ONLY a few hours later. So of course I was pissed with Newegg AGAIN!!! Anyway, I searched the net the rest of the Black Friday day for it without finding it, so ended up settling for the Hynex, which was widely available. However, today I found the Samsung bdie version again, bought it quickly, and canceled my other order for the Hynex, as it was nowhere near ready to ship. All's well that ends well. But I STILL have a serious chip on my shoulder against Newegg. Cheers!