
Piledriver (microarchitecture)

AMD Piledriver Family 15h is a microarchitecture developed by AMD as the second-generation successor to Bulldozer. It targets desktop, mobile and server markets. It is used for the AMD Accelerated Processing Unit (formerly Fusion), AMD FX, and the Opteron line of processors.
The changes over Bulldozer are incremental. Piledriver uses the same "module" design. Its main improvements are to branch prediction and FPU/integer scheduling, along with a switch to hard-edge flip-flops to improve power consumption. This resulted in clock speed gains of 8–10% and a performance increase of around 15% with similar power characteristics. FX-9590 is around 40% faster than Bulldozer-based FX-8150, mostly because of higher clock speed.
Products based on Piledriver were first released on 15 May 2012 with the AMD Accelerated Processing Unit (APU), code-named Trinity, series of mobile products. APUs aimed at desktops followed in early October 2012 with Piledriver-based FX-series CPUs released later in the month. Opteron server processors based upon Piledriver were announced in early December 2012.
Design.
Piledriver includes improvements over the original "Bulldozer" microarchitecture:
Processors.
Desktop.
The K suffix denotes an unlocked A-series processor. All FX-series processors are unlocked unless otherwise specified.
Server.
Some Opteron 32 nm processors.
History.
Komodo platform.
Leaked roadmaps showed Piledriver CPUs featuring up to ten cores as part of the Komodo platform. Komodo was to launch in 2012 on the FM2 socket, but this never happened. AMD kept the AM3+ socket for the FX series and put the Piledriver-based APUs on FM2.
FX-series, Athlon and Opteron.
In 2010 AMD revealed that the 2nd generation was scheduled for 2012; AMD referred to this generation as "Enhanced Bulldozer". This later generation of Bulldozer core was codenamed "Piledriver".
On June 11, 2013, AMD announced two additional FX-series eight "Piledriver" core CPUs, the FX-9590 and FX-9370, running at a maximum turbo speed of 5.0 GHz and 4.7 GHz respectively, making AMD the first company to ever release a 5 GHz CPU commercially. AMD specify that the 9xxx series processors require "robust liquid cooling" due to their high Thermal Design Power (TDP)
For the server market, three versions were stated to be under development:
APU lines.
In January 2013, AMD officially introduced a new series of APUs codenamed "Richland". The series features six new APUs in total. The fastest model, the A10-6800K, featured two "Piledriver" modules operating at 4.1 GHz and 4.4 GHz in turbo mode and an integrated HD 8670D GPU with 384 stream processors operating at 844 MHz. Only the A10-6800K has official DDR3-2133 memory support. The A10-6800K offered approximately 5% performance improvements in performance applications and 3D games over its A10-5800K "Trinity" based predecessor, largely due to "Richland's" higher clock speeds and higher overclocking potential than Trinity. On March 12, 2013, AMD officially introduced four "Richland" mobile APUs. On June 4, 2013, AMD officially announced six "Richland" desktop APUs.
Performance.
In January 2012, Microsoft released two hotfixes (2646060 and 2645594) for Windows 7 and Server 2008 R2 that significantly improved the performance of Clustered Multi-Thread based AMD CPUs by improving thread scheduling.
Windows 8 supports CMT-based CPUs out of the box by addressing each core as logical cores and modules as physical cores.