Advanced Digital Media Boost
The ALU typically breaks instructions into two blocks, which results in two micro ops and thus two execution clock cycles. Intel now extended the execution width of the three ALUs and the load/store units to 128 bits, allowing for eight single precision or four double precision blocks to be processed per cycle. The feature is called Advanced Digital Media Boost, because it also applies to SSE instructions. This is called Single Cycle SSE and, for example, allows for merging four 32-bit element vectors into one 128-bit element.
Intel expects this to make a tremendous difference for all types of media processing applications (encoding, transcoding, compressing, etc.) and it even says the Core offers the highest IA computation density for vector processing.