Today, AMD announced that its long-awaited FX processor, code-named Zambezi, is shipping. This chip is the first of the company's desktop processors to use the new Bulldozer core and targets high-end desktops, where it will be combined with discrete graphics cards, as opposed to the company's A-series processors, known as Llano.

Bulldozer’s architecture uses sets of modules that each contain two integer cores and a single floating point core, along with a shared instruction cache and fetch and decode logic. Zambezi is designed to have four such modules—in other words, eight integer cores and four floating point cores. Each module has a single 2MB level 2 cache, meaning it’s shared by the two integer cores. The overall four-module chip shares an additional level 3 cache of up to 8MB.

AMD is offering four initial chips in this family. The top of the line is the FX-8150 with eight integer cores running at a base speed of 3.6 GHz (with a listed turbo speed of 3.9 GHz and a "max turbo"of 4.2 GHz) at a suggested retail price of $245. Other versions include the 3.1 GHz eight-core FX-8120 (listed with 3.4 GHz Turbo Core, 4.0 GHz Max Turbo) at $205, a 3.3 GHz six core variant called the FX-6100 at $165, and a 3.6 GHz four core version at $115. All are "unlocked" processors aimed at enthusiasts who want to customize their systems to get the most performance they can.

These products are designed to be used with AMD 9-series chipset motherboard and the company's Radeon HD 6000 series graphics cards as part of a platform it calls "Scorpius.”

This is an audacious architecture, with its split of integer and floating point cores, and greater emphasis on higher clock speeds.

I've looked over the initial reviews of the FX-8150 from Anandtech, Legit Reviews, TechReport, Techware Labs, and Toms Hardware.  

The benchmark results are mixed. On most gaming tests and on lightly-threaded workloads, the 8-core FX-8150 underperforms most of the current Intel quad-core products (specifically the quad-core Core i5-2500K and Core i7-2600K). Normally, the older AMD Phenom chips do just as well on these tests.

But the FX does better in many of the tests that use multi-threading more, including compression and encryption tests, and some image editing and video rendering tests. In general, the six-core Intel chips (the Core i7-900 series) take the top spots still, though these chips are much more expensive. The FX is looking quite good, competing well with the more price-competitive quad-core Intel products.

One weak area, not too surprisingly, is heavily-threaded floating point applications. The FX has fewer floating point units than the previous six-core AMD Phenom II chips, along with more instructions that use it. But in general, Turbo Core and overclocking looked quite good.

I look forward to see how it will stack up on my own tests against the current six-core processors and against the upcoming Sandy Bridge-E chips expected from Intel.

Overall, it looks like the chip is a bit more competitive with Intel's quad-core chips, but not the big step forward AMD had hoped for. While AMD would tout giving you eight cores compared with Intel's four for the same price, it doesn't matter if Intel's products are as fast or faster on the broadest range of common applications.

Still, Bulldozer is a more modern architecture. It will be interesting to see how it develops over the next couple of years, as AMD moves towards the next evolution of the core, known as Piledriver.