Feasibility Question - graphic acceleration on CPLD / FPGA ...DSP?
This is, presumably, for ray tracing acceleration?

See also Can FPGA out perform a multi-core PC? 


  A colleague of mine benchmarked this and came to the conclusion that
  FPGAs would outperform a PC once you had more than about 100
  independent, integer tasks that would fit in the FPGA. For floating
  point tasks GPGPU beat FPGA throughout. For narrow multithreading or
  SIMD operation then CPUs are extremely optimised and run at a higher
  clock speed than FPGAs typically achieve.


The MAX10 is a range of FPGAs of varying sizes. They certainly are capable of multiplication: up to 144 different 18x18 calculations per cycle. You need to be careful with FPGA designs not to end up limited by the speed of your DRAM. It's also a fairly substantial project to learn to program one from scratch and the tools are kind of frustrating.

Can the problem be easily divided amongst different chips - well, probably, this kind of tile-based solution is not unusual. Partitioning it is for you to work out or a software question. Remember that coordination between devices is much slower than within devices.

PCIe: I was involved in a project that built some multichannel fast ADC boards with FPGAs mounted in PCIe cards. We had half a dozen soldered by hand by experts, resulting in them costing about $1000 each. The layout took a few weeks; it was done by a graduate student with an experienced engineer looking over his shoulder regularly.

DSPs are built to do integer maths, especially multiply-accumulate (a=b*c+d). See What is the difference between a DSP and a standard microcontroller? They're generally offering similar functionality to SIMD instructions; Intel offer a multiply-accumulate since Haswell.

Could this be done with discrete logic chips?

The paper you linked looks like someone's thesis project of doing actual silicon design - taking that out of the simulator and building a chip from it is again a multiple-thousand dollar operation, and very rarely worth it.

The other approach of assembling chips of varying functions on a PCB has not been sensibly fast since the early 80s.