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You can kind of see how they ended up where they did with TR3. With Zen 1 they had Ryzen going up to 8 cores, Threadripper between 8 and 16 and Epyc picking up
by zrm 7y ago
You can kind of see how they ended up where they did with TR3. With Zen 1 they had Ryzen going up to 8 cores, Threadripper between 8 and 16 and Epyc picking up from there.
For Zen 2 they've got the AM4 Ryzen with up to 16 cores and PCIe 4.0, and Epyc now goes up to 64 but it still starts at 8. Where does that leave for TR3? They got questions about whether they were even going to produce it. If a 16-core Ryzen 9 3950X is $749 and a 16-core Epyc 7302P is $825 then where would you put a 16-core TR3?
It's also possible the new I/O die pushed them to change the socket. Chopping the socket in half to create Threadripper from Epyc is one thing when the socket is already a 4-die package and you can just take two out, but what happens with the new Epyc I/O die which is designed for the whole socket, and could use it even for Threadripper? AM4 and Epyc have all the volume, reworking things like that specifically for compatibility with existing Threadripper boards may not have been worth it. Meanwhile a new socket lets them actually take advantage of the new I/O die to add more PCIe lanes etc.
It stinks that it's not compatible but it smells more like hard trade offs than malice.
- bitL 7y agoFrankly, TR3 is a bit schizophrenic. So they introduced a new socket/platform for supporting up to 64 cores, yet still restricted memory to 256GB UDIMMs, instead of switching over to LRDIMM and allowing up to 4TB of RAM. And the whole platform is dead the moment DDR5 shows up (2021?). Restrict TR3 to top-end only, but limit RAM to low-to-mid-end workstation. It simply doesn't make any sense why to go through all those steps to bypass x399 while not bringing much to the table. Also, no single TRX40 board has more than 4 PCIe slots...
- zrm 7y ago> So they introduced a new socket/platform for supporting up to 64 cores, yet still restricted memory to 256GB UDIMMs, instead of switching over to LRDIMM and allowing up to 4TB of RAM. The only reason all desktops don't support RDIMMs in addition to UDIMMs is market segmentation. The Athlon XP supported both because they were really the same die with the same memory controller as the Athlon MP. They're playing the same stupid game as Intel now but it's nothing new with TR3. They've been doing it since the Athlon 64 or so. Though it's especially annoying because the "workstation" models (FX/TR) have higher clocks than Opteron/Epyc, so there is no way to combine the higher clocked processors with the higher memory capacity boards. > And the whole platform is dead the moment DDR5 shows up (2021?). That happens either way. You're regarding this as a whole new platform they had to design just for this, but it's more like a little tweak on the existing design with the unfortunate side effect of breaking compatibility. > Also, no single TRX40 board has more than 4 PCIe slots... There are boards with four real x16 slots, which is 64 lanes. The other 8 are needed for the on-board devices.