AMD Ryzen 9 7945HX3D vs Intel Core i9-13900 Comparison

The Intel Core i9-13900 and AMD Ryzen 9 7945HX3D are both 92nd-percentile CPUs, but they achieve that status through completely different philosophies. The Intel part is a 24-core desktop monster with a 65 W TDP and a 5.60 GHz boost clock, while the AMD is a 16-core mobile chip with 3D V-Cache, a 55 W TDP, and a 5.40 GHz boost. Benchmark results show a clear split: AMD wins 11 of the 17 head-to-head tests, but Intel wins the marquee multi-threaded rendering tests by wide margins. The data paints a picture of two very different workloads dominating each side.

Head-to-Head Benchmarks

The most striking result is in Cinebench R23 single-core, where the Intel Core i9-13900 scores 5355 against the AMD's 1935 — a 176.7% advantage. That is not a small gap; it is a generational chasm in single-threaded performance. The same pattern appears in Cinebench R15 single-core (539 vs 311, a 73.3% lead for Intel) and PassMark single-thread (4309 vs 4050, a 6.4% edge). If a workload depends on one thread, the Intel part is the obvious choice.

The multi-core picture is more nuanced. In Cinebench R23 multi-core, Intel wins 37931 to 32782, a 15.7% margin. Geekbench multi-core also goes Intel's way: 21164 vs 16758, a 26.3% lead. But Cinebench R15 multi-core tells the opposite story: AMD wins 5600 to 3823, a 31.7% advantage for AMD. This inconsistency suggests the older R15 benchmark favors AMD's architecture in a way that newer tests do not.

Outside of Cinebench, AMD dominates. PassMark multithread shows 57476 vs 45680, a 20.5% win for AMD. Integer math goes 201217 vs 176107 (12.5% for AMD), and floating point math is nearly tied at 121619 vs 120492 — a razor-thin 0.9% AMD edge. The biggest AMD wins come in PassMark extended instructions (52310 vs 32760, a 37.4% lead) and find prime numbers (446 vs 186, a 58.3% blowout). Data compression (699988 vs 577285, 17.5% AMD) and data encryption (42367 vs 35242, 16.8% AMD) also favor the Ryzen.

Random string sorting is another AMD win: 83919 vs 64396, a 23.3% margin. Physics goes 4321 vs 2484, a 42.5% lead for AMD. The only other Intel win besides the single-core tests is Geekbench single-core, where AMD actually scores higher (2769 vs 2604, a 6% AMD win) — but that is listed as an AMD win in the data, so Intel's single-core advantage is not universal. The final tally is 11 wins for AMD and 6 for Intel in the direct comparison.

The Verdict

The data says this: pick the Intel Core i9-13900 if your priority is raw single-threaded speed and modern multi-threaded rendering. Its Cinebench R23 single-core score is 176.7% higher, and its R23 multi-core is 15.7% higher. It also leads Geekbench multi-core by 26.3%. For desktop workloads like compiling, video encoding, or any application that scales across many threads in current benchmarks, Intel wins where it counts.

Pick the AMD Ryzen 9 7945HX3D if your work involves older multi-threaded benchmarks, data processing, or encryption. It wins Cinebench R15 multi-core by 31.7%, PassMark multithread by 20.5%, and integer math by 12.5%. Its 128 MB of shared L3 cache and 1x 64MB 3D V-Cache slice clearly help in data-heavy tasks like compression (17.5% lead) and extended instructions (37.4% lead). The 7945HX3D also wins Geekbench single-core by 6%, so it is not a slouch in single-threaded work — just far behind Intel in the Cinebench single-core tests.

The average benchmark scores tell a similar story: Intel's avg is 60676, AMD's is 59641, a 1.7% gap. But the nearest rivals for each show different competitive positions. Intel sits 0.2% above the Xeon Gold 6338T and 1% above the Ryzen 7 8745HX. AMD sits 0.6% below the Core i9-14900F and 0.8% below the Ryzen 9 7945HX. Both are within 1.2% of their closest competitors, so neither is a runaway leader in overall average.

Where Each One Wins

Intel wins decisively in single-threaded rendering. Cinebench R15 single-core (539 vs 311) and R23 single-core (5355 vs 1935) are not close. PassMark single-thread is closer but still Intel's (4309 vs 4050). For any workflow that is latency-bound on one core — legacy game engines, certain scripting, or lightly threaded productivity — Intel is the pick.

AMD wins in data manipulation and older multi-threaded tests. The 58.3% lead in find prime numbers suggests heavy integer loops favor the Ryzen. The 37.4% lead in extended instructions points to SIMD-heavy code. Data compression and encryption both go AMD by 17.5% and 16.8%, respectively. The 42.5% lead in physics is notable for simulation workloads. Random string sorting (23.3% AMD) reinforces the pattern: AMD handles memory-intensive, pointer-chasing workloads better.

Modern multi-threaded rendering splits. Intel wins Cinebench R23 multi-core (15.7%) and Geekbench multi-core (26.3%), but AMD wins Cinebench R15 multi-core (31.7%). This is a benchmark-specific divergence. If you trust the newer R23 and Geekbench, Intel is better for current multi-threaded apps. If you rely on legacy R15, AMD is the answer.

FAQ

Q: Which CPU has the higher single-core Cinebench R23 score?

A: The Intel Core i9-13900 scores 5355, which is 176.7% higher than the AMD Ryzen 9 7945HX3D's 1935. This is the largest single-core gap in the entire comparison.

Q: How does the AMD Ryzen 9 7945HX3D compare in multi-threaded PassMark?

A: AMD wins PassMark multithread with 57476 vs Intel's 45680, a 20.5% advantage. This is one of AMD's biggest multi-threaded wins.

Q: What is the difference in L3 cache size?

A: The AMD Ryzen 9 7945HX3D has 128 MB of shared L3 cache, which includes a 1x 64MB 3D V-Cache slice. The Intel Core i9-13900 has 36 MB of shared L3 cache. That is a 92 MB difference in favor of AMD.

Q: Which processor has the higher boost clock?

A: The Intel Core i9-13900 boosts to 5.60 GHz, while the AMD Ryzen 9 7945HX3D boosts to 5.40 GHz. Intel's boost is 0.20 GHz higher.

Q: Do both CPUs support ECC memory?

A: Yes, both the Intel Core i9-13900 and AMD Ryzen 9 7945HX3D list ECC memory as supported.

Q: How many wins does each CPU have in the head-to-head benchmarks?

A: The AMD Ryzen 9 7945HX3D wins 11 of the 17 head-to-head tests, while the Intel Core i9-13900 wins 6.

Architecture Differences

The Intel Core i9-13900 uses Raptor Lake architecture on a 10 nm process from Intel, with a die size of 257 mm². It has 24 cores and 32 threads, with 80 KB of L1 cache per core and 2 MB of L2 cache per core. The L3 cache is 36 MB shared. It supports both DDR4 and DDR5 memory on a dual-channel bus, and uses PCIe Gen 5 with 16 lanes from the CPU. Integrated graphics are UHD Graphics 770. The multiplier is locked.

The AMD Ryzen 9 7945HX3D uses Zen 4 architecture on a 5 nm process from TSMC, with a transistor count of 17,840 million and a die size of 2x 71 mm². It has 16 cores and 32 threads, with 64 KB of L1 cache per core and 1 MB of L2 cache per core. The L3 cache is 128 MB shared, featuring a 1x 64MB 3D V-Cache slice. It supports only DDR5 memory on a dual-channel bus, with a memory bandwidth of 83.2 GB/s. It uses PCIe Gen 5 with 28 lanes from the CPU. Integrated graphics are Radeon 610M. The multiplier is unlocked.

The core count difference is significant: Intel has 24 cores vs AMD's 16, but both have 32 threads. Intel's L1 and L2 caches are larger per core (80 KB vs 64 KB L1, 2 MB vs 1 MB L2), but AMD's L3 cache is over three times larger (128 MB vs 36 MB). The memory support also diverges: Intel supports DDR4 and DDR5, while AMD is DDR5-only.

Specification Differences

The two CPUs differ on nearly every base specification. The Intel Core i9-13900 has 24 cores and 32 threads, a base clock of 2000.00 MHz, and a boost clock of 5.60 GHz. The AMD Ryzen 9 7945HX3D has 16 cores and 32 threads, a base clock of 2.30 GHz, and a boost clock of 5.40 GHz. Intel's TDP is 65 W, AMD's is 55 W — a 10 W difference.

Sockets are incompatible: Intel uses Socket 1700, AMD uses Socket FL1. The process nodes differ (10 nm Intel vs 5 nm TSMC), and the foundries are Intel vs TSMC. The die sizes are 257 mm² for Intel and 2x 71 mm² for AMD. L1 cache per core is 80 KB on Intel vs 64 KB on AMD; L2 cache per core is 2 MB on Intel vs 1 MB on AMD; L3 cache is 36 MB shared on Intel vs 128 MB shared on AMD. Memory support is DDR4/DDR5 on Intel vs DDR5-only on AMD. Memory bandwidth is listed only for AMD at 83.2 GB/s. PCIe lanes from the CPU are 16 on Intel vs 28 on AMD, both Gen 5. Integrated graphics are UHD Graphics 770 on Intel vs Radeon 610M on AMD. Market segments differ: Intel is Desktop, AMD is Mobile. The Intel multiplier is locked, AMD's is unlocked. The release dates are January 3, 2023 for Intel and July 26, 2023 for AMD. The Intel part number is SRMB6, and the AMD part number is 100-000001086.