AMD Ryzen Threadripper PRO 9955WX vs Intel Xeon 658X Comparison

Where Each One Wins

The benchmark split is decisively lopsided. The Intel Xeon 658X wins 15 of the 17 recorded head-to-head comparisons, while the AMD Ryzen Threadripper PRO 9955WX takes only 2. That does not mean the AMD chip is a poor performer, it means the workloads tested favor the Intel part's larger core count and cache configuration.

The Xeon 658X dominates every Cinebench test, both multi-core and single-core, by a consistent 5% margin. That includes Cinebench R23 multi-core where the Intel scores 62,466 against the AMD's 59,494. More striking are the PassMark math and physics workloads. The Intel part leads floating point math by 34.7% (210,480 versus 156,215) and physics by 55.7% (6,470 versus 4,156). Prime number finding is the single largest gap: 649 versus 337, a 92.6% advantage.

The AMD Ryzen Threadripper PRO 9955WX wins only the PassMark single-thread tests, scoring 4,530 against the Intel's 3,728, a 17.7% lead. That is a meaningful result for lightly threaded applications, but it is the only area where the AMD part shows a clear edge across the entire recorded benchmark suite.

For rendering, simulation, data compression, encryption, and general multi-threaded number crunching, the Intel Xeon 658X is the stronger chip in this comparison. For single-thread responsiveness and lightly threaded tasks, the AMD part is the better choice. The AMD also lands in the 97th percentile of all CPUs, matching the Intel's percentile, so both are elite parts, just with different strengths.

Specification Differences

The two processors differ across nearly every core specification category. The Intel Xeon 658X has 24 cores and 48 threads. The AMD Ryzen Threadripper PRO 9955WX has 16 cores and 32 threads. Base clocks diverge sharply: the AMD runs at 4.50 GHz while the Intel sits at 3.00 GHz. Boost clocks also favor AMD: 5.40 GHz versus 4.90 GHz.

Thermal design power is higher on the AMD part at 350 W, compared to 250 W for the Intel. The sockets are incompatible: Intel Socket 4710 for the Xeon, AMD Socket sTR5 for the Threadripper. Process nodes differ as well, with the Intel built on Intel's 5 nm process and the AMD on TSMC's 4 nm. Die size is a major differentiator: the Intel uses 2x 598 mm² dies, while the AMD uses 2x 70.6 mm² dies. The AMD lists 16,630 million transistors; the Intel does not have a recorded transistor count.

Cache structures are completely different. The Intel provides 112 KB of L1 per core, 2 MB of L2 per core, and 144 MB of shared L3. The AMD provides 64 KB of L1 per core, 1 MB of L2 per core, and 64 MB of L3. That gives the Intel a substantial 80 MB L3 advantage. The AMD's generation is listed as Ryzen Threadripper (Zen 4 (Storm Peak)), while the Intel is Xeon 600 (Granite Rapids-WS). The AMD's architecture is Zen 5, codename Shimada Peak; the Intel's architecture is Granite Rapids.

Memory support is similar: both use DDR5 with eight-channel memory buses and 409.6 GB/s of bandwidth, and both support ECC. PCIe is also identical: Gen 5 with 128 lanes (CPU only). Neither has integrated graphics. Both have unlocked multipliers. The Intel launched in February 2026 with a launch MSRP of $1699; the AMD launched in July 2025 with a launch MSRP of $1649.

FAQ

Q: Which processor has more cores?

A: The Intel Xeon 658X has 24 cores and 48 threads, while the AMD Ryzen Threadripper PRO 9955WX has 16 cores and 32 threads.

Q: Why does the AMD chip win single-thread tests despite having fewer cores?

A: The AMD part has a base clock of 4.50 GHz and a boost clock of 5.40 GHz, both higher than the Intel's 3.00 GHz base and 4.90 GHz boost. Its PassMark single-thread score of 4,530 is 17.7% above the Intel's 3,728.

Q: Which processor has more L3 cache?

A: The Intel Xeon 658X has 144 MB of shared L3 cache, compared to 64 MB on the AMD Ryzen Threadripper PRO 9955WX. The Intel also has larger L1 and L2 caches per core.

Q: Do both processors support the same memory configuration?

A: Yes, both support DDR5 with an eight-channel memory bus and 409.6 GB/s of memory bandwidth. Both also support ECC memory.

Q: Are these processors unlocked for overclocking?

A: Yes, both the Intel Xeon 658X and the AMD Ryzen Threadripper PRO 9955WX have unlocked multipliers.

Q: Which processor has a higher power draw?

A: The AMD Ryzen Threadripper PRO 9955WX has a TDP of 350 W, while the Intel Xeon 658X has a TDP of 250 W.

Q: Which processor has better multi-threaded performance?

A: The Intel Xeon 658X wins every multi-threaded benchmark in the recorded data, including Cinebench R23 multi-core with 62,466 versus 59,494, a 5% lead.

Head-to-Head Benchmarks

The Cinebench suite shows a uniform picture. Across R15, R20, and R23, the Intel Xeon 658X wins both multi-core and single-core by exactly 5% each time. For Cinebench R23 multi-core, the scores are 62,466 for Intel and 59,494 for AMD. For R23 single-core, the scores are 8,818 and 8,399. The consistency of that 5% delta across all six Cinebench tests suggests a stable architectural advantage rather than a workload-specific quirk.

The PassMark suite tells a more varied story. The largest Intel win is in prime number finding, where it scores 649 against 337, a 92.6% advantage. Physics shows a 55.7% lead (6,470 versus 4,156). Floating point math is 34.7% ahead (210,480 versus 156,215). Data encryption shows an 18% lead (52,357 versus 44,389). Data compression is 15.3% ahead (1,062,062 versus 920,954). Integer math leads by 11.8% (263,995 versus 236,120). Extended instructions lead by 10.8% (84,626 versus 76,363). Multithread leads by 9.6% (73,490 versus 67,035). The narrowest Intel win is random string sorting at 3.2% (103,028 versus 99,813).

The AMD's two wins are the PassMark single-thread tests, which appear twice in the data under slightly different test names, both scoring 4,530 against 3,728, a 17.7% lead. That is the only benchmark category where the AMD part is competitive, and it is a substantial margin. The data suggests the AMD's higher clock speeds translate directly into single-thread performance, but the Intel's extra cores, larger caches, and architecture win everywhere else.

Architecture Differences

The Intel Xeon 658X is built on Granite Rapids architecture, which the database lists as Xeon 600 (Granite Rapids-WS). It uses Intel's 5 nm process with a die size of 2x 598 mm². The AMD Ryzen Threadripper PRO 9955WX uses Zen 5 architecture, codename Shimada Peak, built on TSMC's 4 nm process with a die size of 2x 70.6 mm². The die size difference is enormous, roughly 8 times larger on the Intel side, which reflects a very different physical design approach.

The Intel part is classified as Server/Workstation, while the AMD is classified as Desktop, though both target high-end workstation workloads. Both use the same memory architecture: DDR5, eight-channel, 409.6 GB/s, with ECC support. Both provide 128 PCIe Gen 5 lanes from the CPU. Neither includes integrated graphics.

Cache architecture is the clearest differentiator. The Intel provides 112 KB of L1 per core, 2 MB of L2 per core, and 144 MB of shared L3. The AMD provides 64 KB of L1 per core, 1 MB of L2 per core, and 64 MB of L3. That means the Intel has more than double the L3 cache, plus larger per-core L1 and L2 allocations. For workloads that fit within cache, that advantage is likely a major contributor to the Intel's multi-threaded wins.

Clock strategy also differs fundamentally. The AMD runs a much higher base clock of 4.50 GHz versus 3.00 GHz, and a higher boost of 5.40 GHz versus 4.90 GHz. The Intel compensates with more cores and more cache. The AMD's higher TDP of 350 W versus 250 W suggests it is tuned for maximum clock speed at the cost of power, while the Intel spreads its power budget across more cores.

The Verdict

The data points to a clear split by workload type. If the workload is heavily multi-threaded, the Intel Xeon 658X is the better choice. It wins all Cinebench multi-core tests, all PassMark math tests, compression, encryption, and physics by margins ranging from 5% to 92.6%. Its 24 cores, 48 threads, and 144 MB L3 cache give it a structural advantage in parallel processing that the AMD's 16 cores and 64 MB L3 cannot overcome in the recorded benchmarks.

If the workload is single-threaded, the AMD Ryzen Threadripper PRO 9955WX is the better choice. Its PassMark single-thread score of 4,530 beats the Intel's 3,728 by 17.7%, and its higher base and boost clocks support that result. Applications that rely on one or two threads will feel the difference.

The AMD also has a lower launch MSRP of $1649 compared to the Intel's $1699, though both are firmly in the high-end workstation tier. Both processors sit in the 97th percentile of all CPUs, and both have active production status. The AMD's average benchmark score of 101,041 trails the Intel's 116,060, but that average is dragged down by the AMD's poor showing in math-heavy PassMark tests.

For a builder choosing between these two, the decision comes down to thread utilization. Rendering, simulation, scientific computing, and data processing favor the Intel Xeon 658X. Interactive work, single-threaded scripting, and lightly threaded engineering tools favor the AMD Ryzen Threadripper PRO 9955WX. The Intel is the more versatile all-rounder in this comparison, winning 15 of 17 head-to-head tests, but the AMD's single-thread strength is real and should not be dismissed.