CAB401 | Parallel Performance

In this assignment we were provided a selection of applications & languages to modify & improve. For this I chose a winforms C# application that performs frequency analysis. The provided files includes the university provided application & the modified source.

In order to achieve a performace gain, I implemented numerous notable changes. The most notable of this is the replacement of the included Recursive FFT with a Radix-2 Fast Fourier Transform. This was namely due to its recursive nature restricting the ability to reliably multi-thread. Instead Radix-2 was implemented as it provides an in-thread iterative method of performing the same operation with only caveat being that the resulting output is not in the correct order. To get around this performantly however, a lookup table is generated prior based on the segment size allowing for each resulting segment to be re-order by simplying referring to said table. Additionally, to allow larger scale proccessing, the primary function that initially called the recursive FFT was altered to a Task Queue & Data Queue format in which all Tasks are provided with access to the thread-safe Queue of "Work". Furthermore, all segments of audio are encapsulated in an additional struct object which maintains the segments position during proccessing, allowing the results to be placed in the output array without the possibility of incorrect ordering.

Processor

Intel Core i5 - 9600K (Coffee Lake-S)

  • 6 Physical with 6 Threads
  • (At the time of testing) 4100Mhz
  • L1
    • Instruction
      • 6×32 KBytes
      • TLB : 2MB/4MB, Fully associative, 8 entries
    • Data
      • 6×32 KBytes
      • TLB : 4KB pages, 4-way set associative, 64 entries
  • L2 : 6×256 KBytes
  • L3 : 9MBytes