Re: which FPGA is better?
Just my opinion :
1. Xilinx XC4000(E) is around the performance of Altera EPF8000.
2. But then the successful EPF10K series of Altera beats the XC4000 family, at least in the performance issue, resulted from the fast track connection structure of Altera.
3. After that, Alter is getting ahead of Xilinx for almost one year. Untill the Virtex was born, which again, Xilinx take the leadership of FPGA back from Altera. The success of Virtex, and the succeding families, has lasted for years.
4. In addition to the performance issue of FPGA chip, the tools are another concern. MaxplusII is thought as the key successful issue of altera for its one botton flow, in constrast with Xilinx's ASIC like text mode executables at the beginning. Xilinx then focused on enhancing its GUI, ex. M1, fondation, and now the ISE, while Altera has stayed at its MaxplusII style for long. Buf as the FPGA users become more like experts, the botton of the MaxplusII cannt fullfill them anymore, instead, Xilinx's complex design tools structure attracts people, just like its formal gate array structure of FPGA chips.
5. Since then, Altera far behind Xilinx for years in either way.
6. But Recently, things seem has some changes again. We have some 400k design, as usually running on the most high performance series Xilinx leading familiy(in the sense of process, and thus, the performance), the VirtexII Pro. The design could runs under around 24MHz on slowest speed grade of XC2VP20 part, according to the report. But, when we tried the Altera Cyclon/Stratix, still the slowest speed grade, the design can easily runs around 33MHz. I think if it is not that xilinx has made some conservation of the timing model, it must be that Altera did make a somewhat big step, of the newest FPGAs, the Cyclone & Stratix.