Dual Caches for Dual-core Chips

DominoTree writes "The dual-core chips that AMD and Intel plan to bring to market next year won't be sharing their memories. A version of Opteron coming in 2005 and Montecito, a future member of Intel's Itanium family also slated for next year, will both have two processor cores, the actual unit inside a processor that performs the calculations, and each core will have separate caches."

Comments

Licensing Issues?

[xeon4life]

What will happen to those who must pay a royalty fee per CPU? Will companies that charge for each CPU begin to charge for two, or will it still be viewed as one...?

Re:Note: Here, Single is Better

[spuzzzzzzz]

The dual cache simplifies things emormously, especially taking the design of the Opteron into account. Opterons are incredibly scalable--each one has three HyperTransport links that can be connected to memory, I/O or another processor. In order to make dual-core chips, all AMD has to do is take two Opterons, put them in the same package and hard-wire a HT link from one processor to the other.

Of course, they also need to worry about things like size and power consumption but the simplified architecture really makes things a lot easier and will probably contribute to lower prices. It will also accelerate the introduction of multi-core (ie more than two) processors...

If they were to implement a unified cache design, they would have to make significant changes. They would need to implement cache snooping and complicated memory management. Given that the new dual-core processors (AMD ones, at least) are meant to be pin-compatible with current processors, this would be a bit much to ask. Maybe they'll have unified caches sometime, but I don't see it happening anytime soon.