|"So it seems to me that the 720QM does indeed have 8mb of L3 cache, but 2mb of L3 cache are disable. "|
That's probably what's happening. Intel will probably release a true 6MB part later on. IIRC, when the mobile C2Ds were first released, the T5500 and T5600 processors had 4MB of cache, half of which was disabled. Then a few months later, Intel made Merom-2M versions of the T5000 processors.
HTPC | Pentium M @ 2.82GHz, 2MB L2 | 4GB | 1.0TB | Radeon HD5750
Blu-Ray | Win7 Pro | HDMI out to Onkyo TX-SR707