A little history about this CPU.

This was a replacement under warranty from AMD of the original 5900X I bought (B1 stepping), which had a defective PCIe 16x bus running at only 8x. AMD replaced it with a B2 stepping unit that turned out to be a little monster. This 5900X is factory configured to reach up to 4.95GHz boost clock on 5 cores on CCD0. All the other cores, including CCD1, can hit 4.8GHz (standard specs). Ymmv, depending on the cooling you use. It's a champ at handling anything you can throw at it and feels on par with my 9900X when running desktop apps.

The cooler I used was a Thermalright FrostCommander 140, and temps averaged 43C, in an ITX case when idle with fans at minimum. The highest temp I've seen with this CPU was about 80C under full all-core load (benchmarks).

This was tested on an X570 motherboard, but eventually found its home in the Asus ROG Strix B550-I Gaming with 32GB 3200 CL14 RAM (which I'm also selling in my other listings).

Comes from a non-smoking home, no overclocking besides standard PBO. All pins are intact.

AMD specs:

Name
    AMD Ryzen™ 9 5900X
Family
    Ryzen
Series
    Ryzen 5000 Series
Form Factor
    Desktops, Boxed Processor
Former Codename
    Vermeer
# of CPU Cores
    12
# of Threads
    24
Max. Boost Clock
    Up to 4.8 GHz
Base Clock
    3.7 GHz
L2 Cache
    6 MB
L3 Cache
    64 MB
Default TDP
    105W
Processor Technology for CPU Cores
    TSMC 7nm FinFET
Unlocked for Overclocking
    Yes
CPU Socket
    AM4
Thermal Solution (PIB)
    Not Included
Recommended Cooler
    Liquid cooler recommended for optimal performance
Max. Operating Temperature (Tjmax)
    90°C
Launch Date
    11/5/2020
*OS Support
    Windows 10 - 64-Bit Edition , RHEL x86 64-Bit , Ubuntu x86 64-Bit

PCI Express® Version
    PCIe® 4.0
System Memory Type
    DDR4
System Memory Specification
    Up to 3200 MT/s

Graphics Model
    Discrete Graphics Card Required

Product ID Boxed
    100-100000061WOF
Product ID Tray
    100-000000061

Supported Technologies
    AMD StoreMI Technology , AMD Zen 3 Core Architecture , AMD Ryzen™ Master Utility , AMD Ryzen™ VR-Ready Premium