The same episode we encoded was used for our MP3-testing. We don't recommend using MP3 for encoding, because AC3 does a better job, but nearly 42 minutes gives us approximately the length of any given album.
A measurement in seconds, as many sites do, is useless, because the differences are too small. So we used the built-in play/CPU ratio, this means the CPU is encoding x-times faster then the track-length. Fast memory does not play an important role here.
For your convenience we also show you the single-threaded benchmarks, they will be produced with any other L.A.M.E. version, because only lameMT can do more than one thread and take advantage of a second core.
We used this setting: lamemt --vbr-new -q 2 -V 2 -m j --strictly-enforce-ISO --resample 48