AMD Ryzen 5 PRO 9645 vs Intel Core i9-13900 Comparison

The Intel Core i9-13900 and AMD Ryzen 5 PRO 9645 occupy the same performance percentile (92nd) but achieve it through entirely different strategies. The i9-13900 is a 24-core desktop powerhouse, while the Ryzen 5 PRO 9645 is a 6-core workstation part built on a newer process. The head-to-head data shows a clear split: the Intel chip dominates multi-threaded and math-heavy workloads, while the AMD chip takes single-threaded and prime-number tasks. The i9-13900 wins 8 of the 11 shared benchmarks, with an average benchmark score of 60676 against the Ryzen’s 58916 — a gap of about 3%.

Head-to-Head Benchmarks

The most lopsided result in this comparison is in data encryption, where the Intel Core i9-13900 scores 35242 against the Ryzen 5 PRO 9645’s 17599. That is a 100.3% advantage — the Intel chip doubles the AMD part’s encryption throughput. A similar pattern appears in floating-point math, where Intel leads 120492 to 62720, a 92.1% margin. Integer math also favors Intel heavily: 176107 vs 93019, an 89.3% difference. These three results point to the i9-13900’s raw compute density being far higher, which makes sense given its 24 cores and 32 threads versus the Ryzen’s 6 cores and 12 threads.

The multi-thread benchmark reinforces this trend. Intel scores 45680, while AMD manages 31434 — a 45.3% lead for the i9-13900. Data compression follows suit: 577285 vs 363736, a 58.7% advantage for Intel. Random string sorting shows a 67.7% gap (64396 vs 38410), and extended instructions favor Intel by 10.3% (32760 vs 29705). Even the physics test, which often favors higher single-thread performance, goes to Intel at 2484 vs 1945, a 27.7% win.

The AMD Ryzen 5 PRO 9645’s wins are narrower but meaningful. In single-thread performance, AMD scores 4636 against Intel’s 4309 — a 7.1% lead. The same margin appears in the duplicate single-thread test. The most interesting AMD victory is in the find prime numbers test, where AMD scores 235 vs Intel’s 186. That is a -20.9% delta for Intel, meaning AMD is roughly 26% faster in that specific workload. This is a notable reversal, as prime-number finding often correlates with integer execution efficiency. Despite having far fewer cores, the Ryzen 5 PRO 9645’s per-core strength in this task is substantial.

The overall pattern is decisive: Intel wins the throughput-heavy tests by margins ranging from 10.3% to over 100%, while AMD wins only the single-thread and prime-number tests by single-digit or moderate percentages. The i9-13900’s average benchmark score of 60676 places it just 0.2% ahead of its nearest rival, the Intel Xeon Gold 6338T, and 1% ahead of the AMD Ryzen 9 7945HX. The Ryzen 5 PRO 9645’s 58916 average sits 0.2% above the AMD Ryzen AI 9 HX 470 and 0.7% above the Intel Xeon w5-2545.

Where Each One Wins

The Intel Core i9-13900 is the clear choice for any workload that scales with core count or involves heavy arithmetic. Data encryption, floating-point math, and integer math all show 89-100% leads, making the i9-13900 ideal for encryption tasks, scientific simulations, financial modeling, or any number-crunching application. The 45.3% multi-thread advantage and 58.7% data compression win also make it strong for video rendering, 3D animation, and large-scale data processing. The physics test win (27.7%) suggests it handles physics simulations in games or engineering software better than the AMD part.

The AMD Ryzen 5 PRO 9645 wins where per-core efficiency matters more than raw core count. Its 7.1% single-thread advantage means snappier response in lightly-threaded applications like web browsing, office work, or older games that rely on one or two fast cores. The 26% lead in prime-number finding is specific but real — this matters for cryptography, number theory research, or any software that does heavy prime-generation. The Ryzen 5 PRO 9645 also achieves this with a 65W TDP, identical to the i9-13900’s 65W, but with 6 cores instead of 24, which likely means lower sustained power draw in practice.

For a workstation buyer, the choice hinges on whether the software is multithreaded. If a task uses all available cores, the i9-13900 wins by massive margins. If the task is single-threaded or latency-sensitive, the Ryzen 5 PRO 9645’s newer architecture (Zen 5, 4nm) gives it an edge. The Intel chip’s 10nm process and Raptor Lake architecture are older, but the core count compensates. The data does not show any mixed workload where AMD catches up on throughput — its only wins are in single-thread and prime-number tests.

FAQ

Q: Which CPU has better multi-threaded performance?

A: The Intel Core i9-13900 wins decisively. In PassMark’s multi-thread test, it scores 45680 against the AMD Ryzen 5 PRO 9645’s 31434, a 45.3% advantage. The gap is even larger in floating-point math (92.1%), integer math (89.3%), and data encryption (100.3%).

Q: Does the AMD Ryzen 5 PRO 9645 win any benchmarks?

A: Yes, it wins three of the eleven shared tests: single-thread (4636 vs 4309, a 7.1% lead), the duplicate single-thread test, and find prime numbers (235 vs 186, a 26% lead). These wins are smaller in magnitude than Intel’s multi-thread victories.

Q: How do the average scores compare?

A: The Intel Core i9-13900 has an average benchmark score of 60676, while the AMD Ryzen 5 PRO 9645 averages 58916. This puts the Intel chip about 3% higher overall, and both sit in the 92nd percentile of all CPUs. The i9-13900’s nearest rival, the Intel Xeon Gold 6338T, is only 0.2% behind.

Q: Are these CPUs in the same market segment?

A: No. The Intel Core i9-13900 is listed as a Desktop part on Intel Socket 1700, while the AMD Ryzen 5 PRO 9645 is marked for Server/Workstation use on AMD Socket AM5. Despite the different segments, they share a 65W TDP and both support ECC memory.

Q: Which CPU has more cores and threads?

A: The Intel Core i9-13900 has 24 cores and 32 threads. The AMD Ryzen 5 PRO 9645 has 6 cores and 12 threads. This 4x core difference explains most of Intel’s multi-threaded wins.

Q: Is there a benchmark where the AMD chip scores more than double the Intel chip?

A: No. The largest AMD win is in find prime numbers, where it scores 235 vs 186 — a 26% lead. Intel’s largest win is 100.3% in data encryption, meaning Intel scores more than double AMD in that test.

Specification Differences

The two CPUs differ significantly in core configuration. The Intel Core i9-13900 offers 24 cores and 32 threads, while the AMD Ryzen 5 PRO 9645 provides 6 cores and 12 threads. Base clocks differ: Intel runs at 2000 MHz, AMD at 3900 MHz. Boost clocks are closer, with Intel at 5.60 GHz and AMD at 5.40 GHz. Both have a 65W TDP, but the sockets are incompatible — Intel uses Socket 1700, AMD uses Socket AM5.

Cache hierarchies are notably different. The Intel i9-13900 has 2 MB of L2 cache per core and 36 MB of shared L3 cache. The AMD Ryzen 5 PRO 9645 has 1 MB of L2 per core and 32 MB of shared L3. Both share the same 80 KB L1 per core. Memory support also diverges: Intel supports both DDR4 and DDR5 in dual-channel mode, while AMD supports only DDR5. AMD lists a memory bandwidth of 89.6 GB/s; Intel does not specify a bandwidth figure in the data.

PCIe lanes differ substantially. The Intel chip provides Gen 5 with 16 lanes (CPU only), while AMD provides Gen 5 with 24 lanes (CPU only). Integrated graphics are present on both: Intel has UHD Graphics 770, AMD has Radeon Graphics. The Intel part has a launch MSRP of $549; AMD’s launch MSRP is not provided. Neither CPU has an unlocked multiplier. The Intel part number is SRMB6, while AMD’s is 100-000001409.

Architecture Differences

The architectural gap is significant. The Intel Core i9-13900 uses Raptor Lake architecture on a 10nm process at Intel’s foundry, with a die size of 257 mm². The AMD Ryzen 5 PRO 9645 uses Granite Ridge (Zen 5) on a 4nm process at TSMC, with a die size of 70.6 mm² and 8,315 million transistors. The AMD chip is far denser — its 4nm process allows more transistors in a much smaller area, which contributes to its higher base clock and single-thread efficiency.

The core counts reflect different design philosophies. Intel’s Raptor Lake-S uses a hybrid approach with 24 cores and 32 threads, likely a mix of performance and efficiency cores, though the data does not specify the breakdown. AMD’s Granite Ridge uses 6 full Zen 5 cores with 12 threads. The L2 cache differences (2 MB per core for Intel vs 1 MB per core for AMD) suggest Intel allocates more cache per core, while AMD’s advantage lies in the newer process node and higher base clock.

Generation labels confirm the gap: Intel is Core i9 (Raptor Lake), while AMD is Ryzen 7 (Zen 5 Granite Ridge). The AMD part is newer, with a release date of 2025-09-15, compared to Intel’s 2023-01-03. Both are active in production. AMD’s 89.6 GB/s memory bandwidth is a listed advantage, while Intel’s support for DDR4 gives it flexibility with older memory. The PCIe lane difference (24 for AMD vs 16 for Intel) favors AMD for workstation expansion. Both support ECC memory, which is unusual for consumer parts and points to professional use cases.

The Verdict

The data points to a clear recommendation based on workload. For multi-threaded, compute-heavy tasks, the Intel Core i9-13900 is the superior processor. Its 45.3% multi-thread lead, 92.1% floating-point advantage, and 100.3% encryption margin make it the choice for rendering, simulation, encryption, or any parallel workload. The 24-core configuration delivers throughput that the 6-core AMD chip cannot match, despite the AMD part’s newer process. The i9-13900’s average score of 60676 vs 58916 confirms this overall advantage.

For single-threaded or latency-sensitive tasks, the AMD Ryzen 5 PRO 9645 wins. Its 7.1% single-thread lead and 26% prime-number advantage show that per-core performance is stronger. This makes it a better fit for older software, lightly-threaded applications, or workloads where a single fast core matters more than core count. The AMD chip also offers more PCIe lanes (24 vs 16) and a newer 4nm process, which may appeal to workstation builders looking for efficiency and expansion.

The choice comes down to what the software does. A user running heavily threaded rendering or scientific software should pick the Intel i9-13900 without hesitation — the benchmark gaps are too large to ignore. A user running mostly single-threaded tools or prime-number-heavy cryptography might prefer the AMD Ryzen 5 PRO 9645, accepting lower multi-thread scores for better single-core responsiveness. Both sit in the 92nd percentile, so neither is a weak choice. But the i9-13900 is the performance king in this matchup, winning 8 of 11 benchmarks with margins that often exceed 50%. The Ryzen 5 PRO 9645 wins only 3 tests, and its victories are narrow. For most buyers, the Intel chip is the safer bet for raw performance.