Amazon Warehouse “Like New” Ryzen 9 9900X3D order allegedly arrives as Ryzen 9 3900X
Probably a good example of why buying used PC hardware from Amazon is not a good idea.
Redditor says he bought a heavily discounted “Used – Like New” AMD Ryzen 9 9900X3D from Amazon, but believes the processor in the box was swapped before resale. The post, shared on PCMR, includes photos that prompted other users to question whether the chip is even an AM5 part.
Commenters pointed to two visible red flags. One is the “©2019” marking on the heat spreader, which does not line up with what buyers expect for a Ryzen 9000-series X3D chip. The other is the physical package, which several users described as looking like an AM4 processor rather than an AM5 model.
One reply also highlighted the printed ordering part number, “100-000000023”, which matches the CPU-World listing for the Ryzen 9 3900X. That CPU is a 12-core, 24-thread Zen 2 desktop processor for Socket AM4. It launched in 2019 and carries a 105W TDP.
Source: AMD
By contrast, AMD lists the Ryzen 9 9900X3D as a 12-core, 24-thread desktop CPU with up to 5.5 GHz boost, 4.4 GHz base, 140 MB total cache, and a 120W TDP. AMD said the 9900X3D and 9950X3D were expected in Q1 2025, and later reporting pegged the 9900X3D at a $599 MSRP with a March 12, 2025 on-shelf date.
The socket mismatch matters because AM4 and AM5 CPUs are easy to distinguish once you flip the chip over. AMD’s Socket AM5 platform uses a 1718-contact LGA layout, so the CPU has flat pads and the pins are in the motherboard socket. Socket AM4 uses a PGA layout, so the CPU itself has pins.
Amazon’s “Used – Like New” condition is defined as an item in perfect working condition where packaging may show damage, while essential accessories should be present. The thread’s original poster said they were already preparing a return, and commenters broadly recommended returning the CPU without installing it. For buyers, quick checks include confirming the exact part number on the heat spreader and verifying AM4 pins versus AM5 pads before the chip goes anywhere near a motherboard.
Source: Reddit/PCMR
