Yesterday, AMD launched "Istanbul", their six-core Opteron processor. Paul G. promised that HP would add this CPU into our servers in very short order. "Very short" was right; today we've announced the BL465c G6 and BL495c G6 server blades, both using Istanbul processors, plus we've added it to the HP BL685c G6 server blade.
Andrew Hawthorn gives a nice 3-minute overview of these new servers.
Twenty-four cores would make the BL685c G6 an icosikaitetra-core server. (Names like that are probably why AMD and Intel have stopped using Greek number prefixes for core counts!) Since the BL685c G6 also supports the 4-core Shanghai, and HP has already published some SAP benchmarks with both processors, you can do a side-by-side comparision to see how well some apps scale from 16 to 24 cores.
Full results for the two-tier SAP® Sales and Distribution Standard Application Benchmark are here, but if you just compare the results on BL685c G6 with Shanghai and Istanbul, you'll see that performance scales nicely -- almost 90% linearly -- from 16 cores to 24 cores.