All the Ryzen 1000 processors (including TR) were B1, at least as far as AMD told the USB-IF (and AFAIK nobody ever observed anything else in the wild). Epyc is on B2.
At the time, there was some speculation that B2 might be the "mirror image" die that Epyc uses 2 of.
However, they now report Pinnacle Ridge (Ryzen 2000) as being on the B2 stepping.
Ryzen 2000 is on a slightly updated 12nm process but does not incorporate any library changes. I'm not sure if you could just drop the existing die onto the new process (given that 12nm is really a 14+), or if you could un-flip the die to the proper pinout using the substrate, but it seems like that might be where they moved to the B2 stepping.
But yeah, AMD produced the B1 stepping for an uncommonly long time. At least through the end of 2017, and the first B2 steppings showed up like June 2017.
At the time, there was some speculation that B2 might be the "mirror image" die that Epyc uses 2 of.
http://www.usb.org/kcompliance/view/catalog_search/results_b...
http://www.usb.org/kcompliance/view/view_item?item_key=88142...
However, they now report Pinnacle Ridge (Ryzen 2000) as being on the B2 stepping.
Ryzen 2000 is on a slightly updated 12nm process but does not incorporate any library changes. I'm not sure if you could just drop the existing die onto the new process (given that 12nm is really a 14+), or if you could un-flip the die to the proper pinout using the substrate, but it seems like that might be where they moved to the B2 stepping.
But yeah, AMD produced the B1 stepping for an uncommonly long time. At least through the end of 2017, and the first B2 steppings showed up like June 2017.