Excavator (microarchitecture)

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Excavator – Family 15h (4th-gen)
Produced 2015
Common manufacturer(s)
Min. feature size 28 nm bulk silicon (GF28A)[1]
Instruction set AMD64 (x86-64)
Core name(s)
Predecessor Steamroller – Family 15h (3rd-gen)
Successor Zen

AMD Excavator Family 15h is a microarchitecture developed by AMD to succeed Steamroller Family 15h for use in AMD APU processors. On October 12, 2011, AMD revealed Excavator to be the code name for the fourth-generation Bulldozer-derived core.

The Excavator-based APU for mainstream applications is called Carrizo and was released in 2015.[2][3] The Carrizo APU is designed to be HSA 1.0 compliant.[4] An Excavator-based APU and CPU variant named Toronto for server and enterprise markets will also be available.[5]

Excavator has been confirmed to be AMD's final revision of the "Bulldozer" family, with two new microarchitectures replacing Excavator a year later.[6][7] The next generation sister architectures will be the x86-64 Zen and AArch64 K12 architectures.[8][9]


Excavator is expected to support new instructions such as AVX2, BMI2 and RdRand.[10] Excavator is also expected to come with DDR3 and DDR4 memory controllers, currently not known if on the same die or mutually exclusive.[1] Excavator is designed using High Density (aka "Thin") Libraries normally used for GPUs to reduce electric energy consumption and die size, delivering a 30 percent increase in efficient energy use.[11] Excavator can process up to 15% more instructions per clock compared to AMD's previous core Steamroller.[12]


APU lines[edit]

There are three APU lines announced or released:

  1. Budget and mainstream markets (mobile only): Carrizo APU
    • The Carrizo mobile APUs were launched in 2015 based on Excavator x86 cores and featuring Heterogeneous System Architecture for integrated task sharing between CPUs and GPUs, which allows a GPU to perform compute functions, which is claimed provide greater performance increases than shrinking the feature size alone.[4]
  2. Budget and mainstream markets (desktop and mobile): Bristol Ridge, and Stoney Ridge (for entry level notebooks), APUs[13]
    • Bristol Ridge APUs will utilize socket AM4 and DDR4 RAM
    • Bristol Ridge APUs have up to 4 Excavator CPU cores and up to 8 3rd generation GCN GPU cores
    • Up to a 20% CPU performance increase over Carrizo
    • TDP of 15W to 65W, 15–35W for mobile
  3. Enterprise and server markets: Toronto APU
    • The Toronto APU for server and enterprise markets will feature four x86 Excavator CPU core modules and Volcanic Islands integrated GPU core. The available Toronto APU specifications provides more detail on the upcoming Carrizo APU.[5]
    • The Excavator four modular cores has a greater advantage with IPC than Steamroller. The improvement is 4–15%.
    • Support for HSA/hUMA, DDR3/DDR4, PCIe 3.0, GCN 1.2[4][5][9]
    • The Toronto APU will be available in BGA and SoC variants. The SoC variant will have the southbridge on the same die as the APU to save space and power and to optimize workloads.
    • A complete system with a Toronto APU would have a maximum power usage of 70 W.[5]

CPU Desktop lines[edit]

There are no plans for Steamroller (3rd gen Bulldozer) or Excavator (4th gen Bulldozer) architectures on high-end desktop platforms.

Excavator CPU for Desktop announced on 2nd Feb 2016, named Athlon X4 845.[14]

Athlon X4 845 vs 860K comparison
CPU model Frequency (GHz) Cores TDP (Watt) L1D cache L2 cache PCI Express 3.0 Relative IPC
Athlon X4 845 (Carrizo) 3.5 (3.8 turbo) 4 65 4*32KB 2*1MB X8 1.05–1.15
Athlon X4 860K (Kaveri) 3.7 (4.0 turbo) 4 95 4*16KB 2*2MB X16 1.0

Server lines[edit]

The AMD Opteron roadmaps for 2015 show the Excavator-based Toronto APU and Toronto CPU intended for 1 Processor (1P) cluster applications:[5]

  • For 1P Web and Enterprise Services Clusters:
    • Toronto CPU – quad-core x86 Excavator architecture
    • plans for Cambridge CPU – 64-bit AArch64 core
  • For 1P Compute and Media Clusters:
    • Toronto APU – quad-core x86 Excavator architecture
  • For 2P/4P Servers:


  1. ^ a b http://www.extremetech.com/computing/176919-amd-leak-confirms-that-excavator-apu-will-be-28nm-and-that-some-production-is-moving-back-to-globalfoundries
  2. ^ Reynolds, Sam (October 31, 2013). "New confirmed details on AMD's 2014 APU lineup, Kaveri delayed". Vr-zone.com. Retrieved November 24, 2013.
  3. ^ "AMD updates product roadmap for 2014 and 2015". Digitimes.com. August 26, 2013. Retrieved November 24, 2013.
  4. ^ a b c Hachman, Mark (November 21, 2014). "AMD reveals high-end 'Carrizo' APU, the first chip to fully embrace audacious HSA tech". PCWorld. Retrieved January 15, 2015.
  5. ^ a b c d e Mujtaba, Hassan (December 26, 2013). "AMD Opteron Roadmap Reveals Next Generation Toronto and Carrizo APU Details". WCCF Tech. Retrieved January 15, 2015.
  6. ^ http://www.bit-tech.net/news/hardware/2014/09/11/amd-zen/1
  7. ^ "Archived copy". Archived from the original on 2014-05-13. Retrieved 2014-05-22.
  8. ^ Moammer, Khalid (September 9, 2014). "AMD's Next Gen x86 High Performance Core is Zen". WCCF Tech. Retrieved January 15, 2015.
  9. ^ a b Mujtaba, Hassan (May 5, 2014). "AMD Announces 2014-2016 Roadmap – 20nm Project SkyBridge and K12 64-bit ARM Cores For 2016". WCCF Tech. Retrieved January 15, 2015.
  10. ^ "AMD Excavator Core May Bring Dramatic Performance Increases". X-bit labs. October 18, 2013. Archived from the original on October 23, 2013. Retrieved November 24, 2013.
  11. ^ http://www.tomshardware.com/news/Steamroller-High_Density_Libraries-hot-chips-cpu-gpu,17218.html
  12. ^ http://wccftech.com/amd-carrizo-apu-architecture-hot-chips/
  13. ^ Cutress, Ian (1 June 2016). "AMD Announces 7th Generation APU". Anandtech.com. Retrieved 1 June 2016.
  14. ^ Jeff Kampman (2 February 2016). "AMD puts Excavator on the desktop with the Athlon X4 845".