AMD · Threadripper

Ryzen Threadripper PRO 9955WX

Released July 2025

A 16-core Zen 5 workstation processor for sTR5, with eight-channel DDR5 registered memory and PCIe 5.0 expansion.

Model history · 2 models, 2023–2025

Specifications

Cores: 16
Threads: 32
Base clock: 4.5 GHz
Boost clock: 5.4 GHz
L3 cache: 64 MB
Cores: Shimada Peak; Zen 5 architecture. Boxed 100-100000725WOF; tray 100-000000725. AMD’s 17 July 2025 blog names this model and says PRO 9000 systems are available starting 23 July; announcement and on-sale dates are distinct.
Clocks: Precision Boost 2; Precision Boost Overdrive and Curve Optimizer voltage offsets supported
Cache: L1 1280 KB; L2 16 MB

Socket: sTR5
Base power: 350 W
Unlocked: Yes
Cooler in the box: No
Memory support: DDR5 RDIMM; eight channels; up to 6400 MT/s. ECC enabled by default; AMD EXPO supported. WRX90 supports up to 2 TB; TRX50 reduces this to four channels and up to 1 TB.
PCIe: PCIe 5.0; 148 native/platform lanes, 144 usable, including 128 PCIe 5.0 lanes with WRX90. TRX50 limits expansion to 92 total/88 usable lanes, including 80 PCIe 5.0. Four native USB 3.2 Gen 2 ports and four SATA ports; NVMe boot and RAID 0, 1, 5 and 10 supported.
Chipsets: WRX90, TRX50 and AMD PRO 695; AMD PRO technologies, DASH management and AMD Memory Guard supported. Platform capabilities depend on the motherboard; AMD’s platform guide says OEM systems do not support overclocking.
Process: CPU cores: TSMC 4 nm FinFET; I/O die: TSMC 6 nm FinFET. 3 package dies.
Cooler: Cooler not included; maximum operating temperature 95°C

Closest rivals

Model	Cores	Boost	L3	Power	Socket	Released
AMDRyzen Threadripper PRO 9945WX	12/24	5.4 GHz	64 MB	350 W	sTR5	2025
AMDRyzen Threadripper PRO 7955WX	16/32	5.3 GHz	64 MB	350 W	sTR5	Nov 2023
AMDRyzen 9 9950X3D	16/32	5.7 GHz	128 MB	170 W	AM5	Mar 2025