Intel Core i9-7980xe

[juanrga]

New motherboards, very likely. New sockets, I don't think so. TR4 is a modified SP3 socket which does support 32 cores. I believe AMD actually left in 32 core capability with this socket. Now, the memory question is interesting. One of two things is happening here: 1.) Either TR4 is incapable of supporting processors with eight memory channels. 2.) It is capable of handling eight memory channels. I'm inclined to believe the former, but that doesn't preclude the possibility of having a 32 core processor. It does preclude such a processor being a current Epyc CPU modified for socket TR4. Such a chip would have to be built differently than Threadripper and Epyc CPU's are today. This isn't impossible by any means using the existing socket.

I don't think the TDP needs to come down to half what it is today. It needs to come down within a range that's acceptable in terms of thermal and power limits for the socket, VRD specifications and the packaging of the processor itself. The TDP's also need to come down to a level that not only fits this maximum threshold, but comes in below it enough to allow for a comfortable operating margin. I haven't studied the white papers for Ryzen or Threadripper, and desing guidelines for X399 or socket TR4. Intel makes these available to the general public, but I don't know if AMD does or not. I can ask, but I don't know that they will give them to me.

In any case, the short version is that AMD needs to get the TDP's down to where the VRM's can power the thing and the processor can be cooled with an AIO at stock speeds without frying itself. It's reasonable to assume that they would bring the clock speeds down, but the lower clock speeds of Epyc parts in the server market won't cut it in the HEDT mareket segment. It's not about cutting the TDP in half and doubling the cores, it's about making the right compromises and adjustments necessary to provide a 32 core part that the target market would want.

TR4 = SP3r2, which is electrically incompatible with SP3 socket. EPYC CPUs don't work on Threadripper mobos and ThreadRipper CPUs don't work on EPYC mobos.

TR4 only supports quad-channel. A hypothetical 32-core CPU for TR4 would have a pair of dies accessing memory thought the channels of the other two dies. The latency and bandwidth penalty would be huge and kill performance on all workloads.

My remark about TDP was based in the goal of duplicating throughput. Imagine that 12LP reduces power by 15%. That is not enough to double the number of cores, unless we reduce drastically clocks. We can take a look at 1P EPYC processors. The 7551P has 32C @ 2GHz. Even considering the advantages of 12LP node clocks couldn't hit 2.5GHz. And I consider that is too low clocks for general desktop usage.

So, I don't expect any 32-core ThreadRipper. I expect a refresh of current Threadripper models coming next year in 12LP with the same IPC and same number of cores than current models, but with 7% higher clocks. I then expect new 12/16/24 core Threadripper models for 2019--2020 (Zen2 and 7LP).

 

[Dan_D]

TR4 = SP3r2, which is electrically incompatible with SP3 socket. EPYC CPUs don't work on Threadripper mobos and ThreadRipper CPUs don't work on EPYC mobos.

I am well aware of this. I said nothing to the contrary.

TR4 only supports quad-channel. A hypothetical 32-core CPU for TR4 would have a pair of dies accessing memory thought the channels of the other two dies. The latency and bandwidth penalty would be huge and kill performance on all workloads.

Yes, a hypothetical 32 core CPU would be designed in such a way, but it doesn't necessarily have to be. As I said, it would have to be something that was specifically built to work that way. I said, you couldn't just throw a four die Epyc CPU on there and be golden.

My remark about TDP was based in the goal of duplicating throughput. Imagine that 12LP reduces power by 15%. That is not enough to double the number of cores, unless we reduce drastically clocks. We can take a look at 1P EPYC processors. The 7551P has 32C @ 2GHz. Even considering the advantages of 12LP node clocks couldn't hit 2.5GHz. And I consider that is too low clocks for general desktop usage.

That's exactly what I thought you meant concerning doubling the TDP, and precisely what I said in reference to that idea.

So, I don't expect any 32-core ThreadRipper. I expect a refresh of current Threadripper models coming next year in 12LP with the same IPC and same number of cores than current models, but with 7% higher clocks. I then expect new 12/16/24 core Threadripper models for 2019--2020 (Zen2 and 7LP).

I am not sure what to expect. I do not expect to see a 32 core Threadripper anytime soon, possibly not ever.