convfft vs. fftfilt (1D convolution)

I'd like to use the fastest way for 1D convolution in Matlab. Under the discussions for convfft, it's said that fftfilt is faster than convfft, however i'm using the following equivalent commands (for large vectors), and i found fftconv to be faster. Any suggestions?

res1 = convfft(a,b);

res2 = fftfilt([a,zeros(length(b)-1,1)],[b,zeros(length(a)-1,1)]);

Answer 1

[David Young]

The relative speed depends on the the sizes of the vectors. The best way to find out which is fastest is to experiment - and that's therefore my suggestion.

There's some discussion of the 2-D case here and some experimental results, which show some of the factors you need to take into account.

[Hamed Amini]

Thanks David.