AMD Bulldozer Is Finally Here, but Performance Disappoints

After what can only be described as a long wait, AMD has now finally launched the first FX-Series processors built using its Bulldozer architecture, but despite the high expectations the chips mostly disappoint as they are only marginally faster than previous Phenom II X6 CPUs.

The Bulldozer architecture AMD's FX-Series is based upon is a major departure from all of the company's previous cores, and at its heart stands the Bulldozer module.

Each such module features two integer cores and a shared floating point core paired together with individual L1 cache, a shared L2 cache and a common front end.

The latter includes the fetch and decode logic that is shared by the two integer cores and each module is now capable to fetch and decode up to four x86 instructions from a single thread in parallel.

Architectural improvements were brought by AMD also to the branch predictor, which is now significantly decoupled from the processor's front end, the scheduling and execution units as well as to the integer and floating-point cores, the latter gaining support for a series of new instructions like AVX and FMA4.

AMD uses this new architecture in all of its new FX-Series processors, which includes seven FX-Series processors.

Right now however, AMD has released only four CPUs, the FX-8150, 8120, 6100 and 4100, the first two including four Bulldozer modules for a total of eight cores, while the latter come with six and four cores, respectively.

The clock speeds of the chips launched today range between 3.1GHz and 3.6GHz, all carry 8MB of shared L3 cache and support AMD's Turbo Core 2.0 technology that can automatically raise the operating frequencies depending on the task run and the number of cores loaded.

The sad news however is that despite all the improvements that AMD brought to the Bulldozer architecture, the company's flagship CPU, the FX-8150, lags in most benchmarks Intel's Core i5-2500K, while a few tests even shows it coming behind the Phenom II X6 1100T.

Energy efficiency also isn't a strong point for Bulldozer as both idle and load power measurements show it coming behind Intel's counterparts.

AMD has set the pricing for the AMD FX-8150 at $245 (180 Euros), while the three other processors, the FX-8120, FX-6100 and FX-4100 retail for $205, $165, and $115 (150, 121, 84.5Euro), respectively.