I was waiting for the AMD server lineup to be revealed because I was quite optimist about a 8C/16T Zen with all the I/O of the Server platform. I think that they actually overkilled my expectations since Naples ended up being much wider that I ever dreamed of, which is a lot considering how much I like things that are overengineered...
The model I found the most interesing is the EPYC 7251, because is the closer in price and specs to the consumer Ryzen R7 1800X, but with truckloads of I/O, which was what I found too limiting in consumer Ryzen and still not close enough to Intel HEDT. Sadly, the Frequency of the 7251 is too low, and I doubt that overclocking will be possible in these platforms, so it doesn't look like it will be a viable alternative since the brute performance gap is too big.
The other thing is that the Processor topology is extremely different. While consumer Ryzen is a single Zeppelin die with two CCX, each with 4 Cores and 8 MB Cache L3, the EPYC 7251 instead has 4 dies with a 1+1 CCX but the full 8 MB Cache L3, so basically, it means that you're getting 8 MB Cache L3 PER CORE, which is beastly. However, any intercore communication will incur at the bare least the CCX hoping latency, then the interdie which should be higher. And this is even worse because RAM and PCIe Devices will be local to one die only, so latency should be much higher across the board. I suppose that it may be workable with 4 RAM modules, one for each die, but I doubt consumer Software can scale well with that much NUMA...
For science, I'm extremely interesed in how the 7251 with 4 * 1+1 performs against the consumer 1 * 4+4 Zeppelin (R7 1700/1700X/1800X), assuming that they are underclocked to the same Frequency. That will be an epic match for sure. Heck, if overclocking was possible, with only one Core per CCX, it makes sense that they have a higher Frequency ceiling than a full 4+4. So much dark silicon there...
I suppose that now that we also know that AMD will have ThreadRipper positioned between Ryzen and Naples (Intel is actually doing the same with the new Socket for Kaby Lake-X/Skylake-X) to directly compete against Intel HEDT, chances are that more viable 1800X alternative appears late, since the 7251 lacks Frequency and the platform topology looks unforgiving. But if I had the money, I would love to get one.
