The memory bandwidth of the Phenom II X4 processors has not improved, though we didn't expect it to. Both the first and second generation Phenoms use the same dual-channel DDR2 memory controller. Furthermore, both the Phenom X4 9950 and the newer Phenom II X4 940/920 models were tested with the same DDR2-1066 memory and the same timings.
The new Phenom II X4 processors appear to be a little more efficient when compared to the Phenom X4 9950. The Phenom II X4 920 was 11% faster, while the Phenom II X4 940 was 18% faster than the Phenom X4 9950. They were still left behind by Intel CPUs with ~18% slower performance than the Core 2 Quad Q9650 and a whopping 34% slower than the Core i7 920.
The Phenom II X4 showed reasonably strong Multi-media Int performance with the Phenom II X4 940 scoring just 3% below than the Core i7 920. The Multi-media Float test on the other hand punished the Phenom II X4 processors.
The Phenom II advantage over the original in this test only seemed to be due to the increase in clock frequency.
The core efficiency of the Phenom II X4 processors is still down and while they were noticeably better than the Phenom X4 9950, when compared to the older Core 2 processors the results were dismal.