AMD Ryzen 9 7945HX3D vs AMD Ryzen 7 5800X3D

AMD Ryzen 9 7945HX3D

The AMD Ryzen 9 7945HX3D is a fast high-end laptop processor of the Dragon Range series. It offers 16 cores based on the Zen 4 architecture that supports hyperthreading (32 threads). The cores clock from 2.3 (base) up to 5.4 GHz (single core boost). Compared to the similar R9 7945HX, the 7945HX3D offers an additional 64 MB 3D V-Cache on one CCD-Cluster. This helps in some workloads that can use the additional fast cache (e.g. some games). The guaranteed base clock however was reduced from 2.5 to 2.3 GHz.

The performance of the R9 7945HX3D is similar to the R9 7945HX in workloads that wont make use of the bigger L3 cache. Most games however can use the additional memory. AMD e.g. was advertising the HX3D with 4% to 53% higher performance in 1080p high settings.

The Dragon Range series still uses a chiplet design with two CCD-clusters (each with 8 possible cores) in 5nm and an IO-die (including the memory controller and the Radeon 610M iGPU) in 6nm. The chip integrates 4x USB 3.2 Gen2 (10 Gbps) ports (no USB4), 28 PCIe 5.0 lanes (for GPU and SSDs) and a dual-channel DDR5-5200 memory controller.

The R9 7945HX3D is rated at a TDP of 55 Watt and can be configured up to 75 Watt (cTDP).

AMD Ryzen 7 5800X3D

The AMD Ryzen 7 5800X3D is an 8-core desktop processor with a large level 3 cache (3DV cache) that is aimed mostly for increased gaming performance. It offers 8 Zen 3 based cores clocked at 3.4 - 4.5 GHz and therefore a bit slower than the 3.4 - 4.7 GHz of the R7 5800X. The power consumption of both chips is rated at 105 Watt (TDP) and the efficiency compared to Alder Lake desktop CPUs is rather good.