X-Gene
Developer	AppliedMicro
Manufacturer	TSMC
Type	Microprocessors
Introduction	October 28, 2011 (announced) 2012 (launch)
ISA	ARM
µarch	Storm, Shadowcat, Skylark
Word size	64 bit 8 octets 16 nibbles
Process	40 nm 0.04 μm 4.0e-5 mm , 28 nm 0.028 μm 2.8e-5 mm , 16 nm 0.016 μm 1.6e-5 mm
Technology	CMOS
Clock	2.4 GHz-3.3 GHz
Succession
←	→
PACKETPro	eMAG

X-Gene was a family of 64-bit ARM server microprocessors designed and introduced by AppliedMicro.

Overview

X-Gene was a family of high-performance multi-core ARM microprocessors first announced by AppliedMicro in 2011. Unlike their traditional product offering, X-Gene directly targeted high-performance data center servers, a market predominantly dominated by Intel Xeon processors. AppliedMicro introduced two generations of server processors based on their own custom ARM microarchitectures - Storm and Shadowcat. Those two generations shipped a total of 25,000 units. In late 2016, MACOM acquired AppliedMicro resulting in the shelving of third-generation X-Gene based on the Skylark microarchitecture. The X-Gene intellectual property including most of the design team was eventually sold to Ampere Computing has rebranded the design and improved on it under the eMAG brand.

Naming Scheme

Members

X-Gene 1

See also: Storm microarchitecture

First-generation of X-Gene processors were announced in October 2011 and later launched in late 2012. X-Gene 1 processors are based on the Storm microarchitecture and were fabricated on TSMC's 40 nm process. Those processors had up to four memory channels and up to eight cores operating at up to 2.4 GHz.

• Mem: up to 4 memory channels, DDR3 @ up to 1866 MT/s
• Tech: ARMv8 (ARMv8.0-A)
• I/O: 17 PCIe, SATA/SGMII, 2x SGMII/XFI, 1x RGMII

	List of Storm-based Processors
	Processor				Memory
Model	Launched	Cores	Turbo	L3$	Type	Chans
APM883204-X1	2012	4	2.4 GHz 2,400 MHz 2,400,000 kHz	4 MiB 4,096 KiB 4,194,304 B 0.00391 GiB	DDR3-1866	4
APM883208-X1	2012	8	2.4 GHz 2,400 MHz 2,400,000 kHz	8 MiB 8,192 KiB 8,388,608 B 0.00781 GiB	DDR3-1866	2
APM883408-X1	2012	8	2.4 GHz 2,400 MHz 2,400,000 kHz	8 MiB 8,192 KiB 8,388,608 B 0.00781 GiB	DDR3-1866	4
Count: 3

X-Gene 2

See also: Shadowcat microarchitecture

Second-generation of X-Gene processors were announced in September 2014 and later launched in early 2015. X-Gene 2 processors are based on the Shadowcat microarchitecture and were fabricated on TSMC's 28 nm process. Though those processors were more of a refresh over their predecessor, the new process technology produced lower-power chips at similar performance. Those processors had up to four memory channels and up to eight cores operating at up to 2.4 GHz.

• Mem: up to 4 memory channels, DDR3 @ up to 1866 MT/s
• Tech: ARMv8 (ARMv8.0-A)
• I/O: 17 PCIe, SATA/SGMII, 2x SGMII/XFI, 1x RGMII

	List of Shadowcat-based Processors
	Processor					Memory
Model	Launched	TDP	Cores	Turbo	L3$	Type	Chans
APM883208-X2	March 2015	35 W 35,000 mW 0.0469 hp 0.035 kW	8	2.4 GHz 2,400 MHz 2,400,000 kHz	8 MiB 8,192 KiB 8,388,608 B 0.00781 GiB	DDR3-1866	2
APM883408-X2	March 2015	35 W 35,000 mW 0.0469 hp 0.035 kW	8	2.4 GHz 2,400 MHz 2,400,000 kHz	8 MiB 8,192 KiB 8,388,608 B 0.00781 GiB	DDR3-1866	4
Count: 2

X-Gene 3

See also: Skylark microarchitecture

Third-generation of X-Gene processors were announced in 2016 and started sampling in 2017. X-Gene 2 processors are based on the Skylark microarchitecture and were fabricated on TSMC's 16 nm process. AppliedMicro made large changed to the system architecture of the chip and some minor changes to the core. The chip design shifted from incorporating an array of accelerators on-die to offering a large set of I/O (mostly PCIe lanes) so that high-performance PCIe-based accelerators could be attached instead. In 2017 AppliedMicro sold the X-Gene assets to Ampere Computing and consequently discontinued the X-Gene line. X-Gene 3 has re-launched by Ampere under the eMAG family.

• Mem: 8x DDR4 channels, up to 2666 MT/s with ECC; 1 TiB/socket
• I/O: 42 PCIe Gen 3 lanes
• TDP: Up to 125 W

	List of Skylark-based Processors
	Processor					Memory
Model	Launched	TDP	Cores	Turbo	L3$	Type	Chans
APM883832-X3		125 W 125,000 mW 0.168 hp 0.125 kW	32	3 GHz 3,000 MHz 3,000,000 kHz	32 MiB 32,768 KiB 33,554,432 B 0.0313 GiB	DDR4-2666 DDR4-2400	8
Count: 1

See also

• Cavium ThunderX2
• Qualcomm Centriq

Bibliography

• AppliedMicro. (October 30, 2013). "AppliedMicro Announces General Availability of X-Gene System Development Kit for ARM 64-Bit Platform".
• AppliedMicro. (March 08, 2017). "MACOM Announces Sampling of X-Gene® 3 Server-on-a-Chip® Solution".
• David Schor. (February 5, 2018). "X-Gene 3 gets a second chance at Ampere with a new 32-core 16nm ARM processor".