Starting this summer, AMD will move its lineup to the SOI 45nm process. The first cores will be Deneb, which is a direct shrink of Agena and should arrive in the second half. At the same time, Barcelona, the server equivalent, will be shrunk to 45nm SOI and dubbed Shanghai. Heka, the triple-core version, is slated for early 2009. Istanbul is in turn the code-name of the six-core derivate of Shanghai, and it wasn’t long ago it first appeared on the roadmaps. Istanbul is meant to launch in early 2009, and the biggest news is of course the two additional cores.
The previously mentioned octo-core Montreal has been scrapped in favor of the native six-core Istanbul, which will go dodeca-core with two dies glued together in 2010. The reason is suppose to be a more cost-efficient approach, and perhaps just a tiny bit because Intel also has a hexa-core coming, Dunnington.
Istanbul sports 6MB L3 cache, 512KB L2 cache per core, and DDR2 or DDR3, depending on the socket (AM2+ or AM3). Chip architect dude Hans de Vries has now posted a die-shot of Istanbul (artist rendering), and a few words to go with the picture;
Click to enlarge
“It’s probably not a bad idea for AMD to take advantage of their relatively small core size. At 45nm it can cram two cores (with 256 kB L1 total) into 30mm2. A single Nehalem core with 256 kB L2 also occupies ~30 mm2.
So in terms of IPC/mm2 you get two cores against one core with 2 threads.
The 8 core Nehalem seems to be a megamacholomaniamonolitic die. larger still as Dunnington (700 mm2 ?) More for bragging rights purpose as for profitability, considering that it will be rather TDP limited.
Istanbul could be at or just below 300 mm2. Istanbul/Sao Paulo should become a mass market 32nm device so it’s not a bad idea in terms of risk reduction to develop them as server/workstation chips at 45nm.
It is better to add cores, to 6 in total, as to extend the L2 caches from 512kB to 1MB per core on a 4-core device as was planned with Montreal.”
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