AMD FX CPUs

 Written by Gareth Halfacree on 14 March, 2011


AMD today officially released the inaugural models in its new line of AMD FX high-performance consumer CPUs. The chips, which during their development were code-named "Zambezi," are based on the "Bulldozer" core design AMD unveiled last year.

Intended primarily for gamers and enthusiasts who regularly perform "extreme" tasks, the new chips help round out the upper end of AMD's 2011 releases, following the budget-aimed E Series and the midrange A Series. All the CPUs in the AMD FX line come with unlocked multipliers for easy overclocking, and support for both high-resolution displays and AMD's Eyefinity multimonitor technology, but do not include integrated graphics and therefore require the use of a discrete video card. CPUs in the FX family will only work in motherboards based on AMD's AM3+ socket and utilizing AMD 9-Series chipsets.

Each Bulldozer unit in a CPU contains two dedicated cores (that support two processing threads), but share some functionality between them to reduce "bursty" or inefficient usage in certain situations. Dynamic resource allocation also exists between the threads. (When only one thread is active, that thread can access all the resources that are typically shared.) AMD claims that this configuration improves throughput on multithreaded workloads and offers "greater scalability and predictability than two threads sharing a single core."

AMD says these design changes also help the chips be more power efficient. Also playing a role are flip-flop clock gating throughout the design, dynamically power-gated circuits, and a number of additional power-saving features that can be controlled by firmware or software, such as C6 state, Core P-states and AMD Turbo Core technology, Application Power Management, DRAM power management, and a C1E low-power idle state.

With these chips AMD has also introduced a number of instruction set extensions, including for SSE 4.1 and 4.2, Advanced Vector Extensions (AVX), AES, XSAVE state space management, and XOP instructions.

The flagship CPU in the FX family is the FX-8150, which has a base CPU speed of 3.6GHz (which, with AMD's Turbo Core capability, can increase to as much as 4.2GHz in certain situations), and a full eight processing cores in addition to 8MB of L2 cache and a Thermal Design Power (TDP) of 125 watts.

Also available at launch, and slated to ship before the end of October, will be another eight-core chip, the FX-8120 (3.1 GHz, with Turbo Core taking its clock speed up to 4 GHz, and with a TDP of 125 watts), the six-core FX-6100 (3.3 GHz to 3.9 GHz, 95-watt TDP), and the four-core FX-4100 (3.6 GHz to 3.8 GHz, 95-watt TDP). All FX-series chips will have 8 Mbytes of L3 cache and support RAM up to DDR3-1866.

The FX-8150, FX-8120, and FX-6100 are slated to list for $245, $205, and $165 when they're made available later in October; AMD has not yet confirmed pricing on any of its other chips.

PCMag is working on its review of the AMD FX-8150. Check back by the end of the week to see how it stacks up to previous processors from both AMD and Intel.