AMD launches eight-core FX desktop chips built on Bulldozer cores

AMD has unveiled its FX line of processor chips that feature up to eight processor cores based on the Bulldozer architecture and are chiefly aimed at enthusiasts and high-end gamers.

The AMD FX, otherwise known as Zambezi, is claimed to be the world's first eight-core desktop processor by AMD and will ship at clock speeds up to 4.2GHz, although only a handful of speeds will be available initially.

These will be the eight-core FX 8150 and FX 8120, clocked at 3.6GHz and 3.1GHz, respectively, while the FX-6100 is a six-core chip clocked at 3.3GHz. Further models, including quad-core versions, will ship later.

The new chips are the first available based on AMD's Bulldozer next-generation core, which has been designed to have enough performance headroom to power successor chips for the next five or six years, according to AMD technical advisor Bernard Seité.

Bulldozer is unusual in that each chip is based on a number of modules, each consisting of two integer execution units plus shared functional blocks, including a floating point execution unit (FPU). Four modules are thus needed to make an eight-core processor.

This design was chosen to reflect the fact that that most workloads are integer-based, and hence the FPU in conventional core designs is often under-utilised.

"Having a shared unit allows two cores to use a larger and more higher performing unit than would be the case if each core had its own FPU," Seité explained.

While every module has 2MB of L2 cache, the two integer cores inside have their own dedicated L1 cache, with 8MB of L3 cache shared between the modules via an on-chip integrated Northbridge.

The on-chip Northbridge also has two 72-bit memory channels for DDR3 memory, plus four HyperTransport links connecting with the rest of the host system.

As AMD is aiming the FX chips primarily at gamers and enthusiasts the whole range is fully unlocked to enable overclocking, according to the firm.

AMD also confirmed that pricing for the top-end FX 8150 chip will be around $245 (£156) but didn't give pricing information for any of the other chips.