AMD's Fusion is a multi-die package

THE AMD FUSION NOTION is slowly taking shape, with controlled leaks to interested parties, I am led to understand.

To get the big picture, it is necessary to understand what Fusion actually is. For a company that has openly said that Intel's products aren't true dual-core (Presler) and are not true quad-core (Kentsfield/Clovertown), Fusion will be the beginning of a new way of thinking at Chimpzilla. By copying Intel's moves, that is.

Fusion is nothing but a MCM (multi-chip module), similar to ones that are already around. Like Intel quad-core Kentsfield/Clovertown and ATI's own Xenos for Xbox 360.

The cores, memory controller and the Hypertransport are located on one die, while the GPU is located on another, connected to the main package with AMD's own tech. This is not the only MCM that will come from AMD. Montreal is two Shanghai dies slapped together onto a Socket F+/AM3, so eight-core Opterons/Phenoms will be something that Intel already sells today - two pieces of silicon using a single socket.

As you can see with ATI's Xenos, the MCM is the simplest form of glueing more silicon dies onto the same package

AMD, Chartered and TSMC are all involved in manufacturing Fusion processors in one way or another, not just one.

AMD's Fab36 and Chartered will be in charge of manufacturing the CPU part of the package, while TSMC will manufacture the graphics part. This will significantly reduce the cost of manufacturing, since it will lower the risk of yields going awry. Neither of the companies in question has experience to produce a complete CPU/GPU being glued onto the same chip module.

When it comes to the future, it is obvious that AMD will want to create a monolithic die with both CPU and GPU part glued together, but with 45 nanometre and 55 nanometre manufacturing processes being a reality in 2008, first generation will have to be MCM packed.

We're unsure which socket this processor will use, and whether it will be compliant with existing sockets like the AM2+ and AM3. Yet. µ