I'm in the feasibility stage of a project and I was testing the computational performance of PPC and Microblaze. I 'm using a 1024 FFT written in C (fixed-point). At this point I don't really care about the time that is needed to read (beginning) and write (end) all these data. I care only about the computational time. To measure the performance I do a Modelsim simulation by using the VHDL files produced by EDK. For Microblaze I'm using the ML506 board and for the PPC the ML507. I also use the highest frequency that the tool allows (without timing errors). The problem is that PPC seems to be almost 2 times slower than Microblaze which I think its not very logical. They both use internal FPGA BRAMs for Instruction and Data memories. One thing that also seems a little bit strange to me is that when I use PPC the EDK does not let me use bus frequency grater than 133.33 MHz. Maybe this is my bottleneck but I don't have experience on PPC so I need you help.I'm alsmost sure that I do something wrong but I don't know what. If you need more info just ask.
Thanks in advance
p.s. I also opened a Web-Case and I'm waiting the Xilinx's answer but I thought to send it here also