Re: fpga speed logic/density MIPS/FLOPS as compared to general purpose microprocessors

Peter Alfke wrote:

Geoffrey,
the most important aspect is the freedom in systems architecture
offered by FPGAs. This allows you to use massive parallelism for higher
performance, or serial processing for lower cost etc.
If you look just at clock rate, FPGAs suffer a penalty imposed by the
interconnect flexibility. You have to compensate for that by taking
advantage of the architectural flexibility offered in FPGAs.
And do not forget (dynamic) reconfigurability...
Peter Alfke, Xilinx Applications

For video processing the biggest impact that this flexibility has is on memory bandwidth. I have watched attempts to use DSP chips for video processing, I have studied using them, and I have been involved to varying degrees with a number of successful video processing designs using FPGAs.

In all cases the FPGA won the design primarily because you can make the memory as wide as you need, and can often play tricks like having multiple memory buses feeding the processing. When you have a processing algorithm that requires more than one frame buffer, or a frame buffer and coefficient memory operating simultaneously, a DSP with one memory interface just can't cut it. By the time you pile enough DSPs on a board to equal the performance of an FPGA solution you're burning holes in the carpet with the power dissipation.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com
.

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