It has been a long time coming, but word is that a formal announcement of AMD's Barcelona architecture is to be made at a special event tonight, if the press release circulated to some US tech sites is to be believed.
For those not aware, Barcelona is AMD's first quad-core chip and uses a native quad-core architecture as opposed to Intel's solution of bundling two dual-core processors together. Harking back to the days of K6, AMD is once again including a Level 3 cache (though this time it's all on-die). All the cores will share 2MB of L3 cache, while boasting 512KB of L2 and 128KB of L1. This is a striking amount less than Intel's offerings, which sport huge 8MB L2 caches. This is justifiable however, as the super fast HyperTransport links, introduced with the K7 architecture, should compensate, by ensuring speedy communications between cores.
Memory support is confirmed as DDR2 only for now, with DDR3 supporting processors, as well as motherboards and chipsets, coming at a later date. A DRAM pre-fetcher has now made it into the memory controller. Its function is to pre-load any data from RAM that's likely to be wanted by the processor into cache, the idea being to both increase operating speed and reduce power by reducing the time the processor spends waiting for data.
Speaking of power consumption, AMD has now added another term to its ratings known as Average Power Consumption (APC). The company feels it needs to stress the difference between TDP, the engineers predicted maximum power-draw and the amount of power that is actually likely to be used in normal operation. So for example, a processor with a TDP of 120W might have an APC rating of 105W and improved power management enables quad-core parts to operate with roughly the same TDPs as current dual-core Opterons.
AMD also claims that the new architecture will be price/performance competitive with Intel. While internal benchmarks probably shouldn't be taken as gospel, the results do imply a significant performance advantage in the particular areas tested by AMD. It's possible that once again we'll have to choose between either AMD or Intel based on the applications that are going to be run.
As regards to pricing, for 1,000-unit orders, AMD Opteron 2300-series chips (designed for 1-2 processor motherboards) will cost from $206 for a 1.7GHz model to $372 for a 2.0GHz part. At the high-end 8300-series chips (which support up to eight processors in tandem) will cost from $688 for a 1.8GHz chip to $1,004 for a 2.0GHz chip.
While the prices and benchmarks for server chips may not be directly useful for predicting the same for Phenom desktop parts when they arrive, the current level of synergy between desktop, notebook and server chips in both the green and blue camps does make it seem likely that we can expect some interesting things from Barcelona once AMD can get a decent production level going. Barcelona-based Opterons are supposed to ship next month, so we may well see Phenom before the year is out.
Update: AMD has now published the press release on the website, link added below.