Built with:
cl /Ox -D_USE_MATH_DEFINES /arch:SSE test_pffft.c pffft.c fftpack.c
(visual c++ is definitively not very good with SSE intrinsics...)
| N (input length) | real FFTPack | real PFFFT | cplx FFTPack | cplx PFFFT |
|---|---|---|---|---|
| 64 | 173 | 1009 | 174 | 1159 |
| 96 | 169 | 1029 | 188 | 1201 |
| 128 | 195 | 1242 | 191 | 1275 |
| 192 | 178 | 1312 | 184 | 1276 |
| 256 | 196 | 1591 | 186 | 1281 |
| 384 | 172 | 1409 | 181 | 1281 |
| 512 | 187 | 1640 | 181 | 1313 |
| 768 | 171 | 1614 | 176 | 1258 |
| 1024 | 186 | 1812 | 178 | 1223 |
| 2048 | 190 | 1707 | 186 | 1099 |
| 4096 | 182 | 1446 | 177 | 975 |
| 8192 | 175 | 1345 | 169 | 1034 |
| 9216 | 165 | 1271 | 168 | 1023 |
| 16384 | 166 | 1396 | 165 | 949 |
| 32768 | 172 | 1311 | 161 | 881 |
| 262144 | 136 | 632 | 134 | 629 |
| 1048576 | 134 | 698 | 127 | 623 |