Look at the first example, the "Deerhound" quad-core CPU based on the K8L core tune-up, which AMD is supposed to ship in volumes during the 3rd quarter of 2007. This Opteron-class server CPU has only 2 MB of shared L3 cache according to my deep throat - less than the L2 cache on the current Woodcrest! if each core has its own 1 MB L2, and there are four of them, what extra use is such a small common L3 for? Well, two answers - one is to remove the inter-core and cache coherency traffic from the crossbar and keep it within that L3 cache. And the other? Well, AMD might again rely on "exclusive" cache policy, not copying the data from L2 into L3 in this case, but keeping additional code and data there.You can read more over at The Inquirer.
Further in mid-2008, using the same 65 nm process, AMD refreshes its line with new quad-core parts: "Cerberus" high-end Opteron MP, and "Wolfhound" Opteron DP. While Cerberus enjoys a larger (but still somehow weak) 6 MB L3 cache together with fast 2.4 GHz HyperTransport 3 (19.2 GB/s bandwidth per link, to match the built-in DDR3 memory controller speed), its DP cousin still sticks with paltry 2 MB L3 - and, hey, that is mid 2008 period!
AMD quad-core processor details
Posted on Thursday, May 11 2006 @ 22:50 CEST by Thomas De Maesschalck