An engineering sample of the unreleased AMD Ryzen 9 5900X3D processor has appeared on the Chiphell forum. The 12-core, 24-thread Zen 3 chip, identified by code 100-000000652, features 128 MB of L3 cache. This configuration consists of 96 MB on one CCD and 32 MB on the other, indicating that only one of the two six-core chiplets includes the 64 MB 3D V-Cache stack.
This design differs from the prototypes AMD showcased in 2023, which featured 192 MB of cache across both CCDs. The single-stack architecture allows for higher clock speeds, with CPU-Z data showing the chip operating at approximately 4.7 GHz with a 105 W TDP, compared to the 4.4 GHz boost limit of the dual-stack prototype.
The processor requires specific hardware conditions to function, as it does not operate on current BIOS versions. The sample successfully booted only with an older BIOS version using SMU firmware 56.70.0. The owner has requested that ASRock provide support for this chip in future firmware updates.
AMD has not officially commented on this engineering sample. The single-CCD cache layout observed on this unit is similar to the approach AMD later implemented for its Ryzen 9 X3D chips on the AM5 platform, prior to the release of the Ryzen 9 9950X3D2 Dual Edition.
