AMD Ryzen Threadripper PRO 9955WX

The AMD Ryzen Threadripper PRO 9955WX is a 16-core, 32-thread desktop processor built on the Zen 5 architecture and TSMC's 4nm process, with a boost clock of 5.40 GHz and a 350W TDP. It launched on July 22, 2025, with a launch MSRP of $1649. Benchmark data places it in the 98th percentile of all CPUs, with an average score of 100,227, indicating top-tier performance among desktop processors.

Benchmark Performance

The Ryzen Threadripper PRO 9955WX delivers exceptional multi-threaded results across all Cinebench versions. In Cinebench R23, it scores 59,494 points multi-core and 8,399 points single-core; R20 shows 24,987 multi-core and 3,527 single-core; R15 yields 5,996 multi-core and 846 single-core. These numbers reflect a consistent ~7x scaling from single-core to multi-core, a strong indicator of efficient parallelization across its 16 cores and 32 threads.

Passmark results reinforce this profile. The multithread score is 69,993, while single-thread reaches 4,561. Specialized workloads show particular strengths: data compression scores 890,743, floating point math 148,042, and integer math 246,111. Extended instructions (AVX-class workloads) hit 70,809, while encryption and physics score 48,476 and 7,056 respectively. The average benchmark score of 100,227 places it in the 98th percentile, meaning it outperforms nearly all other CPUs in the database.

Against its nearest rivals, the 9955WX sits in a tight performance cluster. It trails the AMD EPYC 4585PX by 0.6%, leads the AMD Ryzen Threadripper PRO 5965WX by 1.7%, and falls behind the AMD EPYC 7513 by 2% and the AMD EPYC 8324P by 3%. These deltas are small, indicating that the 9955WX is competitive with enterprise-class server chips despite being marketed as a desktop processor.

Platform and Compatibility

The processor uses AMD Socket sTR5, a platform designed for high-core-count Threadripper PRO parts. Memory support is DDR5 with an eight-channel bus, yielding a theoretical bandwidth of 409.6 GB/s. ECC memory is supported, which is critical for error-sensitive workloads such as scientific computing or long-running renders. The CPU provides 128 PCIe Gen 5 lanes from the CPU itself, enabling massive expansion for GPUs, NVMe storage, and high-speed networking. There is no integrated graphics, so a discrete GPU is mandatory. The multiplier is unlocked, allowing overclocking, though the 350W TDP already demands substantial cooling. The processor is built on a 4nm TSMC process with 16,630 million transistors across a dual-die design (2x 70.6 mm²). The cache hierarchy includes 64 KB L1 and 1 MB L2 per core, plus 64 MB shared L3. This platform targets professional workstations, not mainstream desktops, and its upgrade path is limited to other sTR5-compatible parts.

Single-Thread vs Multi-Thread Behavior

The split between single-thread and multi-thread performance is decisive. In Cinebench R23, the single-core score of 8,399 is strong on its own, but the multi-core score of 59,494 is over 7 times higher. This ratio persists across R20 (3,527 vs 24,987) and R15 (846 vs 5,996), showing that the CPU scales nearly linearly with core count. Passmark single-thread (4,561) versus multithread (69,993) yields a 15.3x ratio, though this metric aggregates different workloads. The implication is that the 9955WX excels in heavily parallel tasks—rendering, video encoding, simulations, and code compilation—where all cores can be utilized. For lightly threaded applications like legacy office suites or some games, the high single-thread score ensures responsiveness, but the processor's true strength emerges when workloads spread across all 16 cores. The consistent scaling across Cinebench versions confirms that the Zen 5 architecture and 4nm process efficiently feed all cores without significant contention.

How It Compares

AMD EPYC 4585PX – The 9955WX trails this EPYC part by just 0.6% in average benchmark score. The EPYC 4585PX is a server-grade chip, and the near-tie means the Threadripper PRO offers comparable raw compute in a desktop form factor, albeit with a different feature set (e.g., 128 PCIe lanes vs EPYC's platform).

AMD Ryzen Threadripper PRO 5965WX – The 9955WX is 1.7% faster than its predecessor in the same product line. This is a modest generational gain, but the 9955WX also brings a newer architecture (Zen 5 vs Zen 4) and higher boost clock (5.40 GHz vs 4.50 GHz base), which may show larger differences in specific workloads not captured by the average.

AMD EPYC 7513 – The 9955WX is 2% slower than this EPYC chip. Given that the EPYC 7513 is a server processor with likely different core counts (though not specified), the Threadripper PRO still holds its own in average compute, while offering a desktop-oriented platform with eight-channel memory and 128 PCIe lanes.

AMD EPYC 8324P – The 9955WX trails by 3%. This is the largest gap among the nearest rivals, but still within a small margin. The EPYC 8324P is a higher-end server part, and the 3% deficit in average score suggests the 9955WX is not far off from enterprise-class performance, while being more accessible in a workstation build.

Who Should Consider It

The Ryzen Threadripper PRO 9955WX is built for professionals who need massive multi-threaded throughput without stepping into dual-socket server territory. Its Cinebench R23 multi-core score of 59,494 and Passmark multithread of 69,993 make it ideal for 3D rendering, video editing, scientific simulation, and data analysis—workloads that can use all 16 cores and 32 threads. The eight-channel DDR5 memory with 409.6 GB/s bandwidth supports large datasets, and the 128 PCIe Gen 5 lanes allow multiple high-end GPUs or NVMe arrays. Single-thread performance (8,399 in R23) is strong enough for everyday productivity, but the processor is not optimized for typical gaming; while it can handle games, the high TDP and lack of integrated graphics make it a poor fit for a gaming-only PC. For content creators, engineers, and researchers who require both compute density and expansion capability, the 9955WX is a compelling option. Its 98th percentile standing ensures it will handle the most demanding tasks without bottlenecking.

FAQ

Q: What socket does the AMD Ryzen Threadripper PRO 9955WX use?

A: It uses AMD Socket sTR5.

Q: How much L3 cache does it have?

A: It has 64 MB of shared L3 cache, with 64 KB L1 and 1 MB L2 per core.

Q: What memory type and channels does it support?

A: It supports DDR5 memory with an eight-channel bus, providing 409.6 GB/s of bandwidth, and it supports ECC memory.

Q: How many PCIe lanes does the CPU provide?

A: It provides 128 PCIe Gen 5 lanes from the CPU itself.

Q: What is the TDP and can it be overclocked?

A: The TDP is 350W, and the multiplier is unlocked, so overclocking is possible with adequate cooling.

Q: When was it released and what is its part number?

A: It was released on July 22, 2025, and the part number is 100-000000725.

Power and Thermals

The 350W TDP classifies the 9955WX as a high-power desktop processor. This demands a robust cooling solution—typically a large tower air cooler or a high-end liquid cooler—to maintain sustained performance. The unlocked multiplier allows overclocking, which will increase power draw beyond the 350W TDP, so any cooling solution must have headroom. The 4nm process helps mitigate heat density, but the dual-die design (2x 70.6 mm²) still concentrates heat. In practice, users should plan for a cooling system capable of dissipating over 350W under load, and a motherboard with a strong VRM design is essential to feed the CPU without throttling. The 128 PCIe lanes and eight-channel memory also generate additional heat in the system, so proper case airflow is critical. The 9955WX is not a power-efficient part; it prioritizes raw performance over energy consumption, and its thermal profile reflects that trade-off. For workstations that run long multi-threaded jobs, a well-ventilated chassis and a high-capacity cooler are non-negotiable.