AMD is giving finishing touches to its 3rd generation Ryzen Threadripper HEDT processor lineup, and the first wave of these chips, starting with a 24-core model, will launch alongside the AMD TRX40 chipset. It turns out that the chipset won’t be compatible with 1st and 2nd generation Ryzen Threadripper processors. The upcoming 3rd generation Threadripper chips won’t be backwards-compatible with the AMD X399 chipset, either. We’ve been hearing from reliable sources rumors of this segmentation from AMD for a few days now, and tech journalist ReHWolution just tweeted its confirmation having obtained info on upcoming motherboards from ASRock. The company is working on the TRX40 Taichi and TRX40 Creator motherboards.
ASRock TRX40 Taichi & Creator coming in November. Not backward compatible with 1st and 2nd Gen Threadripper CPUs. Also, 3rd Gen TR CPUs won’t work on X399 boards. @ReHWolution
The underlying reason between this restriction remains a mystery. We know that the EPYC “Rome” MCM is pin-compatible with first-generation EPYC “Naples” chips due to the fact that the newer chips are drop-in compatible with older servers via a BIOS update. The TR4 socket, too, is nearly identical to SP3r2, but for four out of eight memory channels being blanked out. It remains to be seen if for TRX40 motherboards, AMD re-purposed these unused pins for something else, such as additional PCIe connectivity or more electrical pins. We’ll find out in November, when AMD is expected to launch these chips.
Source: ReHWolution (Twitter), TPU