What's proving to be a problem though is where does this fit? If you don't have a clear need for an FPGA then just buy a normal Xeon. If you do need an FPGA then why compromise your Xeon? Have an FPGA card, or hell a group of FPGA cards.
The only place this makes sense is if you can think of a use case where you have an FPGA task that needs low latency communication with your CPU. Even with this chip though you have an uphill struggle because the cache hierarchy of a Xeon makes access to memory non-deterministic which traditionally isn't what FPGAs are designed for. It's much more difficult to design your algorithm on FPGA to deal with arbitrary memory latency.
So the question back to you is: What would you use it for?
The TI AM335x CPU has something (sort of) like this...basically 2 microcontrollers that share memory with the ARM cpus.
People have done some pretty clever things with it. Audio processing, driving LED matrix boards, emulating old video boards, driving precision servos, software oscopes and logic analyzers, etc.
Though that's in a small dev board, like the Beaglebone Black, not a beefy Intel server.
It doesn't have a use case, at least not yet. But easy, cheap gains are running out in general-purpose computing as we near 1nm process. Heterogenous computing will then become more relevant, and a great way to do that is an FPGA.
My rule of thumb from a few years ago: given the same semiconductor process, you roughly have a 40x area difference between ASIC and FPGA for the same amount of random logic.
There are few things that can be done very well on a FPGA, but most things are not, and the market for it tiny.
If you really have an application that's perfect for a CPU/FPGA combo, just buy a PCIe card with a beefy FPGA.
It will cost you, but the development of the FPGA logic will cost way more.
Because 2 FPGA cores don't give you the same bang for your computational buck as 2/4 general purpose cores. You're better off hanging an FPGA off a fast internal bus with an expansion card, rather than try and cram an FPGA on a CPU die.
Think of them like graphics cards, but even more niche. Trying to stick them directly into the CPU isn't going to provide the power of a dedicated add on.
Although if they are on-die, you can benefit from shared L2/L3 cache, and lower power/increased performance of the CPU-FPGA coupling, shared memory path (lower cost than dedicated, although they can compete/starve each other if there isn't good synergy at the OS level.)
Yeah, the problem is any FPGA solution that integrates directly with the CPU cache is going to be a bit underpowered due to fitting on the silicon. Even the integrated CPU/FPGA SoCs I've seen have the ARM core separated by an interconnect
What's proving to be a problem though is where does this fit? If you don't have a clear need for an FPGA then just buy a normal Xeon. If you do need an FPGA then why compromise your Xeon? Have an FPGA card, or hell a group of FPGA cards.
The only place this makes sense is if you can think of a use case where you have an FPGA task that needs low latency communication with your CPU. Even with this chip though you have an uphill struggle because the cache hierarchy of a Xeon makes access to memory non-deterministic which traditionally isn't what FPGAs are designed for. It's much more difficult to design your algorithm on FPGA to deal with arbitrary memory latency.
So the question back to you is: What would you use it for?