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WuDaoKou µarch
General Info
Arch Type	CPU
Designer	Zhaoxin
Manufacturer	HLMC
Introduction	December 28, 2017
Process	28 nm
Core Configs	2, 4, 8
Pipeline
Type	Superscalar
OoOE	Yes
Speculative	Yes
Reg Renaming	Yes
Instructions
ISA	x86-64
Succession
Zhangjiang LuJiaZui

WuDaoKou is the successor to Zhangjiang, a 28 nm x86 microarchitecture designed by Zhaoxin for mainstream laptops, desktops, and servers.

Brands

Family	Series	Description
KaiXian	KX (5000)	Desktop, Laptops
KaisHeng	KH (20000)	Storage, Servers

Release Dates

WuDaoKou-based chips taped out on November 9, 2017. The architecture and SKUs were officially unveiled at a conference on December 28, 2018.

Process Technology

WuDaoKou is manufactured on HLMC's 28 nm process.

Architecture

Key changes from Zhangjiang

• 1.4x performance
• 8 cores per die (up from 4)
• SoC design
  • New Uncore
    • northbridge moved on-die
    • PCIe 3.0 (from 2.0)
    • DDR4 (From DDR3)
  • New integrated graphics processor
    • HD Audio Output/Codec
• Core
  • Pipeline was reduced by 5 stages
  • Execution engines were re-balanced
  • Branch prediction unit was reworked and optimized
• FSB removed
  • x4 PCIe 3.0 communication with southbridge chipset
• Chipset
  • Gigabit Ethernet port (RGMII)
  • USB 3.1 Gen2 (Type-C) ports
  • SATA 3.0 ports

This list is incomplete; you can help by expanding it.

Block Diagram

This section is empty; you can help add the missing info by editing this page.

Memory Hierarchy

• Cache
  • L1D Cache
    • 32 KiB, 8-way set associative
    • Per core
  • L1I Cache
    • 32 KiB, 8-way set associative
    • Per core
  • L2 Cache
    • 4 MiB, 32-way set associative
    • Per quad-core cluster
• System DRAM
  • 2 Channels
  • DDR4, Up to 2400 MT/s

Sockets/Platform

All parts use a HFCBGA 37.5×37.5 mm package and are effectively a system on a chip. However, for the most part, those parts get paired with a chipset which serves as an I/O extension chip. The chipset communicates with the microprocessor over standard PCIe 3.0 x4 lanes.

Chipset
Chipset	TDP	PCIe		SATA	USB			Network	Process	Package
		2.0	3.0	3.0	2.0	3.1 Gen 1	3.1 Gen 2
ZX-200	6 W	9 lanes	-	4	6	3	2	10/100M/1 Gbps	40 nm	FCBGA (21mm x 21mm)

Die

• HLMC 28 nm process
• 187 mm² die size
• 2,100,000,000 transistors

All WuDaoKou Processors

	List of WuDaoKou-based Processors
	Main processor
Model	Family	Launched	Cores	L2	Frequency	Max Memory	ECC
KH-25800	KaisHeng	28 December 2017	8	8 MiB 8,192 KiB 8,388,608 B 0.00781 GiB	1.8 GHz 1,800 MHz 1,800,000 kHz	128 GiB 131,072 MiB 134,217,728 KiB 137,438,953,472 B 0.125 TiB	✔
KH-26800	KaisHeng	28 December 2017	8	8 MiB 8,192 KiB 8,388,608 B 0.00781 GiB	2 GHz 2,000 MHz 2,000,000 kHz	128 GiB 131,072 MiB 134,217,728 KiB 137,438,953,472 B 0.125 TiB	✔
KX-5540	KaiXian	28 December 2017	4	4 MiB 4,096 KiB 4,194,304 B 0.00391 GiB	1.8 GHz 1,800 MHz 1,800,000 kHz	64 GiB 65,536 MiB 67,108,864 KiB 68,719,476,736 B 0.0625 TiB	✘
KX-5640	KaiXian	28 December 2017	4	4 MiB 4,096 KiB 4,194,304 B 0.00391 GiB	2 GHz 2,000 MHz 2,000,000 kHz	64 GiB 65,536 MiB 67,108,864 KiB 68,719,476,736 B 0.0625 TiB	✘
KX-U5580	KaiXian	28 December 2017	8	8 MiB 8,192 KiB 8,388,608 B 0.00781 GiB	1.8 GHz 1,800 MHz 1,800,000 kHz	64 GiB 65,536 MiB 67,108,864 KiB 68,719,476,736 B 0.0625 TiB	✘
KX-U5580M	KaiXian	28 December 2017	8	8 MiB 8,192 KiB 8,388,608 B 0.00781 GiB	1.8 GHz 1,800 MHz 1,800,000 kHz	64 GiB 65,536 MiB 67,108,864 KiB 68,719,476,736 B 0.0625 TiB	✘
KX-U5680	KaiXian	28 December 2017	8	8 MiB 8,192 KiB 8,388,608 B 0.00781 GiB	2 GHz 2,000 MHz 2,000,000 kHz	64 GiB 65,536 MiB 67,108,864 KiB 68,719,476,736 B 0.0625 TiB	✘
Count: 7