AMD Ryzen Threadripper PRO 3945WX vs Intel Core i5-7400 Comparison

# AMD Ryzen Threadripper PRO 3945WX vs Intel Core i5-7400

The benchmark data presents an extraordinary mismatch: the AMD Ryzen Threadripper PRO 3945WX wins all eight head-to-head tests against the Intel Core i5-7400, with margins ranging from 59.9% to 513.5%. This is not a contest between peers; it is a comparison between a 12-core workstation processor from 2020 and a 4-core desktop chip from 2017, and the data reflects that generational and segment gulf. The Threadripper PRO's average benchmark score of 7741 places it in the 64th percentile of all CPUs, while the Core i5-7400's 7469 average lands it just one percentile lower at 63. Yet those overall percentiles obscure the sheer scale of the head-to-head deltas, which are among the largest seen in this database.

Head-to-Head Benchmarks

The largest margins appear in the Cinebench multi-core tests, where the Threadripper PRO 3945WX's 12 cores and 24 threads overwhelm the i5-7400's 4 cores and 4 threads. In Cinebench R15 multi-core, the AMD scores 2869 against Intel's 469, a 511.7% advantage. The pattern repeats in Cinebench R20 multi-core with 11956 versus 1956 (511.2% delta) and in R23 multi-core with 28469 versus 4658 (511.2% delta). These near-identical percentage gaps across three generations of Cinebench suggest a consistent scaling factor: the Threadripper PRO delivers roughly six times the multi-threaded rendering throughput in every version of that benchmark. The data implies that whatever workload benefits from multi-core scaling in one Cinebench version benefits equally in the others.

Single-core results tell a more nuanced story, though the AMD still wins decisively. In Cinebench R15 single-core, the Threadripper PRO scores 404 against 66, a 512.1% delta — nearly identical to its multi-core margin. That is surprising: a 12-core Zen 2 chip should not typically outpace a 4-core Kaby Lake part by 5x in single-threaded work. The i5-7400's scores here are anomalously low across all single-core tests (66 in R15, 275 in R20, 657 in R23), which drags down its average and inflates the AMD's relative advantage. By contrast, Geekbench single-core shows a far more modest 59.9% delta (1668 versus 1043), a number that aligns better with expectations for two processors from different eras. The Cinebench single-core numbers may indicate that the i5-7400 was running under different conditions or that the benchmark version penalizes its older architecture more heavily.

Geekbench multi-core confirms the multi-threaded trend but with a smaller margin: 10854 versus 2740, a 296.1% delta — roughly four times the performance, not six. This discrepancy between Cinebench and Geekbench multi-core results (511% vs 296%) suggests that the workloads stress different subsystems. Cinebench is heavily cache- and memory-bandwidth-sensitive, where the Threadripper PRO's 64 MB L3 cache and 204.8 GB/s eight-channel memory bandwidth provide enormous advantages. Geekbench's more varied workload mix may not scale as purely with core count, explaining the smaller but still dominant margin.

The i5-7400 does have additional PassMark tests in its data pack — data compression (76268), encryption (1611), extended instructions (6452), prime numbers (27), floating point (12042), integer math (14293), multithread (5475), physics (438), random string sorting (9301), and single thread (2074) — but no comparable results exist for the Threadripper PRO, so these cannot be used for direct comparison. The absence of matching test data limits the head-to-head analysis to the eight shared benchmarks, all of which the AMD wins.

FAQ

Q: Why is the multi-core performance difference so much larger in Cinebench than in Geekbench?

A: The data shows a 511.7% delta in Cinebench R15 multi-core versus a 296.1% delta in Geekbench multi-core. Cinebench workloads are more sensitive to the Threadripper PRO's 64 MB L3 cache and 204.8 GB/s memory bandwidth, while Geekbench's mixed workload scales less dramatically with core count.

Q: Does the Intel Core i5-7400 win any benchmark category?

A: No. The head-to-head results show 8 wins for the AMD Ryzen Threadripper PRO 3945WX and 0 wins for the Intel Core i5-7400. The closest margin is Geekbench single-core at 59.9% in favor of the AMD.

Q: How do these processors compare to their nearest rivals?

A: The Threadripper PRO 3945WX's 7741 average score is 1.7% ahead of the Intel Core i5-4590 (7609), 2.2% ahead of the AMD Ryzen Threadripper 2990WX (7578), and 2.3% ahead of the Intel Core i5-6500 (7569), but 2.1% behind the Intel Core i9-10980XE (7910). The i5-7400's 7469 average is 0.6% ahead of the Intel Core i5-4570 (7421), 0.7% ahead of the Intel Core i9-9990XE (7415), 0.8% ahead of the AMD EPYC 7282 (7409), and 1% ahead of the Intel Core i9-9980XE (7398).

Q: Are both processors still in production?

A: Yes, the data lists both the AMD Ryzen Threadripper PRO 3945WX and the Intel Core i5-7400 with a production status of "Active."

Q: Do either of these CPUs support ECC memory?

A: Yes for the AMD, no for the Intel. The Threadripper PRO 3945WX has ECC memory support set to true, while the Core i5-7400 has it set to false.

Q: What is the difference in their memory bandwidth capabilities?

A: The Threadripper PRO 3945WX provides 204.8 GB/s through an eight-channel DDR4 memory bus, while the Core i5-7400 provides 38.4 GB/s through a dual-channel DDR4 bus — a 5.3x difference in theoretical bandwidth.

Where Each One Wins

The AMD Ryzen Threadripper PRO 3945WX is the clear choice for multi-threaded rendering, as shown by its Cinebench R23 multi-core score of 28469 versus the i5-7400's 4658. Any workload that scales with core count — video rendering, 3D animation, scientific computing, virtual machines — will see roughly six-fold improvements based on the Cinebench deltas. The Threadripper PRO's 128 PCIe Gen 4 lanes and eight-channel memory subsystem further position it for workstation tasks that move large datasets. Its 64 MB L3 cache and 204.8 GB/s bandwidth make it suited for in-memory analytics and large simulation workloads.

The Intel Core i5-7400, despite losing every shared benchmark, retains a niche in its additional PassMark results. Its data compression score of 76268, floating point math of 12042, and integer math of 14293 indicate it handles everyday productivity tasks — office applications, web browsing, basic photo editing — without issue. Its 65 W TDP versus the AMD's 280 W makes it far less demanding on cooling infrastructure, and its integrated HD 630 graphics mean it can run without a discrete GPU. For legacy desktop systems on Socket 1151, the i5-7400 remains a functionally adequate CPU for light workloads, though the benchmark data shows it cannot compete in any compute-intensive scenario.

The Geekbench single-core gap of 59.9% (1668 versus 1043) is the closest any test comes to parity between these two. For single-threaded legacy applications that cannot use multiple cores, the i5-7400 is less catastrophically outclassed, but it still loses by a wide margin. The data provides no category where the Intel chip wins; the "where it wins" case is purely about adequate baseline performance in workloads not represented in the shared benchmark set.

Specification Differences

The core specifications diverge sharply. The AMD Ryzen Threadripper PRO 3945WX has 12 cores and 24 threads, while the Intel Core i5-7400 has 4 cores and 4 threads. Base clocks are 4.00 GHz for the AMD versus 3.00 GHz for the Intel; boost clocks are 4.30 GHz versus 3.50 GHz. TDP differs dramatically: 280 W for the AMD, 65 W for the Intel.

Memory configurations are also different: the AMD uses eight-channel DDR4 with 204.8 GB/s bandwidth, while the Intel uses dual-channel DDR4 with 38.4 GB/s. ECC memory is supported on the AMD but not the Intel. PCIe connectivity differs significantly — the AMD offers Gen 4 with 128 lanes (CPU only), while the Intel offers Gen 3 with 16 lanes (CPU only). The AMD has no integrated graphics, whereas the Intel includes HD 630.

Cache hierarchies diverge: the AMD has 64 KB L1 per core and 512 KB L2 per core (identical to the Intel's L1), but the AMD's L3 is 64 MB versus the Intel's 6 MB shared. The Intel's L2 is 256 KB per core, half the AMD's. The AMD's die size is listed as 2x 74 mm², while the Intel's die size is not provided in the data. Transistor count for the AMD is 7,600 million; the Intel's is not listed.

Architecture Differences

The AMD Ryzen Threadripper PRO 3945WX is built on Zen 2 architecture, codenamed Castle Peak, and fabricated on a 7 nm process by TSMC. It belongs to the Ryzen Threadripper generation and the 3000 series, targets the Server/Workstation market segment, and uses AMD Socket WRX8. Its multiplier is locked, despite the enthusiast-class positioning.

The Intel Core i5-7400 uses Kaby Lake architecture (same codename), fabricated on a 14 nm process by Intel. It belongs to the Core i5 Kaby Lake generation, targets the Desktop market segment, and uses Intel Socket 1151. Its multiplier is also locked. The AMD was released on 2020-07-13, while the Intel was released on 2017-01-02 — a 3.5-year gap that explains much of the performance difference.

The process node difference (7 nm versus 14 nm) contributes to the AMD's ability to pack 12 cores while the Intel manages only 4 in a similar power envelope consideration — though the AMD's 280 W TDP is substantially higher. The AMD's dual-die design (2x 74 mm²) with 7,600 million transistors reflects a chiplet approach, whereas the Intel's monolithic design details are not provided. The AMD also lacks integrated graphics, reinforcing its workstation focus, while the Intel's HD 630 makes it a self-contained desktop solution.

The Verdict

The data supports only one conclusion for performance-sensitive buyers: the AMD Ryzen Threadripper PRO 3945WX is categorically superior in every shared benchmark. Its 511.7% lead in Cinebench R15 multi-core and 513.5% lead in R20 single-core are not incremental improvements — they represent generational and segment leaps. The 12-core, 24-thread configuration with 64 MB L3 cache and 204.8 GB/s memory bandwidth delivers 4-6x performance in rendering and multi-threaded workloads.

The Intel Core i5-7400's case rests entirely on its 65 W TDP, integrated HD 630 graphics, and adequate PassMark scores in everyday tasks. For a desktop user with a Socket 1151 motherboard who needs a basic CPU for office work and light media consumption, the i5-7400 remains functional. Its 7469 average benchmark score and 63rd percentile placement show it is not obsolete — it sits just one percentile below the Threadripper PRO in overall standing.

Who should pick which? The AMD is for professionals running Cinebench-class workloads: video editors, 3D animators, engineers, and data scientists who need the 128 PCIe Gen 4 lanes and eight-channel memory. The Intel is for users with existing Socket 1151 systems who need a low-power, no-GPU-required chip for basic tasks, and who do not run the multi-threaded applications where the AMD dominates. The 59.9% Geekbench single-core gap is the closest comparison, but even that favors the AMD decisively. There is no benchmark scenario in the shared data where the Intel wins, and any buyer choosing the i5-7400 for performance reasons would be making a choice contradicted by every available measurement.