AMD Ryzen 5 PRO 7645 vs AMD Ryzen 7 7800X3D Comparison

The AMD Ryzen 7 7800X3D and the AMD Ryzen 5 PRO 7645 both belong to the 7000 series, built on the Zen 4 architecture with the Raphael codename, and share the AMD Socket AM5 and a 5 nm process node from TSMC. Despite these similarities, the recorded benchmark data shows two very different performance profiles. The Ryzen 7 7800X3D wins 12 of the 15 head-to-head comparisons, while the Ryzen 5 PRO 7645 takes three, and the margins in each direction reveal which workload types favor which processor.

Head-to-Head Benchmarks

The most decisive victory for the Ryzen 7 7800X3D comes in PassMark physics, where it scores 3,522 against the Ryzen 5 PRO 7645’s 1,598. That is a lead of 120.4 percent, meaning the 7800X3D more than doubles the physics throughput of the 7645. This is the largest relative gap in the entire comparison and points to a substantial advantage in heavily threaded, simulation-style workloads.

The 7800X3D also dominates in PassMark integer math, scoring 103,639 versus 74,782, a 38.6 percent advantage. Its floating point math score is 61,187 against 45,202, a 35.4 percent lead. Data compression shows 384,669 versus 286,298, a 34.4 percent edge, and data encryption follows at 22,346 versus 16,657, a 34.2 percent gain. Extended instructions land at 29,166 versus 21,813, which is 33.7 percent ahead, and random string sorting is 45,418 versus 34,557, a 31.4 percent lead. The multithread score is 34,293 versus 25,489, a 34.5 percent margin. In every one of these PassMark subtests, the 7800X3D holds a lead between roughly 31 and 38 percent, with the exception of the extreme physics result.

The 7800X3D also wins the single-thread PassMark tests, though by a much smaller margin. Its score of 3,759 is just 2.9 percent above the 7645’s 3,652. This is a narrow victory, far smaller than the multithreaded gaps, and it indicates that in lightly threaded PassMark work the two processors are close.

In Cinebench R15 multicore, the 7800X3D scores 2,878.5 against 2,188, a 31.6 percent win. This aligns with the PassMark multithread result and reinforces the pattern that the 8-core part has a clear edge in most multi-threaded rendering tasks.

The Ryzen 5 PRO 7645 takes the other three head-to-head tests, and its wins are concentrated in Cinebench. In Cinebench R23 multicore, the 7645 scores 21,710 against the 7800X3D’s 16,817, a 22.5 percent advantage. This is a surprising result given that the 7800X3D won Cinebench R15 multicore by 31.6 percent. The reversal between the two Cinebench versions suggests that the newer R23 workload rewards the 7645’s higher boost clock, which is 5.10 GHz versus 5.00 GHz, or its different cache behavior.

The 7645’s lead in Cinebench R23 singlecore is even larger. It scores 3,065 against 1,713, a 44.1 percent advantage. That is a massive gap in single-threaded rendering. The Cinebench R15 singlecore result tells a similar story, with the 7645 at 308 versus 281.5, an 8.6 percent edge. The R15 margin is modest, but the R23 margin is huge, indicating that the 7645 has a substantial single-core performance advantage in at least one modern rendering benchmark.

Overall, the head-to-head data shows a clear split. The 7800X3D wins most multithreaded and math-heavy PassMark tests by wide margins, while the 7645 wins the Cinebench R23 tests, especially singlecore, by a very wide margin. The 7800X3D’s average benchmark score is 33,079, while the 7645’s is 32,446, a difference of about 2 percent in favor of the larger chip. Both sit at the 83rd percentile among all CPUs in the database.

The Verdict

The recorded data suggests that the Ryzen 7 7800X3D is the stronger choice for users whose workloads resemble the PassMark suite. Its leads of 34 to 38 percent in integer math, floating point math, data compression, encryption, extended instructions, and multithreaded performance are consistent and large. The physics result, at more than double the 7645’s score, makes it particularly well suited for simulation and physics-heavy applications. Anyone running parallel compute tasks, data processing, or encryption-heavy workloads should favor the 7800X3D based on these numbers.

The Ryzen 5 PRO 7645, despite its lower core count, is the better option for single-threaded Cinebench workloads. Its 44.1 percent lead in Cinebench R23 singlecore is the second-largest margin in the entire comparison, and its 22.5 percent win in R23 multicore shows that it can outperform the 7800X3D in certain modern rendering scenarios. The 7645 also edges out the 7800X3D in Cinebench R15 singlecore, though by a smaller 8.6 percent. Users who rely on Cinebench R23, particularly for single-threaded rendering or compatibility testing, would see better scores with the 7645.

The 7800X3D wins the single-thread PassMark test by 2.9 percent, so the 7645’s single-core advantage is not universal. It appears specific to the Cinebench workloads. For general single-threaded performance as measured by PassMark, the two are nearly tied, with the 7800X3D holding a slight edge.

The 7800X3D also benefits from a higher average benchmark score, 33,079 versus 32,446, and a better standing among its nearest rivals. Its closest competitor, the AMD Ryzen 7 8700G, has an average score of 33,089, essentially identical. The 7800X3D is also within 0.4 percent of the AMD Ryzen 9 PRO 6950H, which scores 33,201. The 7645, by contrast, sits near the AMD Ryzen 7 6800HS at 32,354, within 0.3 percent, and the Intel Core i5-14400F at 32,279, within 0.5 percent. These rival comparisons place the 7800X3D in slightly higher-performing company, though the differences are small.

In terms of production status, both are active. The 7800X3D launched on 2023-01-03, while the 7645 launched on 2023-06-12. The 7800X3D has a launch MSRP of $449, which may be noted for reference but does not factor into the performance analysis.

FAQ

Q: Which CPU has a higher score in Cinebench R23 multicore?

A: The AMD Ryzen 5 PRO 7645 scores 21,710, which is 22.5 percent higher than the AMD Ryzen 7 7800X3D’s 16,817.

Q: What is the largest performance gap in the head-to-head comparison?

A: The largest gap is in PassMark physics, where the AMD Ryzen 7 7800X3D scores 3,522 versus 1,598 for the AMD Ryzen 5 PRO 7645, a 120.4 percent advantage.

Q: How do the two CPUs compare in single-threaded PassMark tests?

A: The AMD Ryzen 7 7800X3D scores 3,759, which is 2.9 percent higher than the AMD Ryzen 5 PRO 7645’s 3,652.

Q: Does the AMD Ryzen 5 PRO 7645 win any multithreaded tests?

A: Yes, it wins Cinebench R23 multicore with a score of 21,710 against 16,817, a 22.5 percent lead. It loses Cinebench R15 multicore by 31.6 percent.

Q: What are the average benchmark scores for each CPU?

A: The AMD Ryzen 7 7800X3D has an average benchmark score of 33,079, while the AMD Ryzen 5 PRO 7645 has an average score of 32,446.

Q: Which CPU has a higher boost clock?

A: The AMD Ryzen 5 PRO 7645 has a boost clock of 5.10 GHz, compared to 5.00 GHz for the AMD Ryzen 7 7800X3D.

Specification Differences

The two processors differ in core count, thread count, clock speeds, thermal design power, cache sizes, market segment, release date, and part number. The AMD Ryzen 7 7800X3D has 8 cores and 16 threads, while the AMD Ryzen 5 PRO 7645 has 6 cores and 12 threads. The base clock of the 7800X3D is 4.20 GHz, while the 7645 runs at 3.80 GHz. The boost clock is 5.00 GHz for the 7800X3D and 5.10 GHz for the 7645, giving the smaller chip a 0.10 GHz higher maximum frequency.

The thermal design power differs substantially. The 7800X3D is rated at 120 W, while the 7645 is rated at 65 W. The L3 cache also differs, with the 7800X3D featuring 96 MB shared L3 cache and the 7645 featuring 32 MB shared. Both have 64 KB L1 cache per core and 1 MB L2 cache per core. The transistor count is 11,270 million for the 7800X3D and 6,570 million for the 7645, though both have a die size of 71 mm². The 7800X3D is listed as a Desktop segment product, while the 7645 is listed as Server/Workstation. The 7800X3D has a part number of 100-000000910, and the 7645 has 100-000000600. The 7800X3D has a launch MSRP of $449, while the 7645 has no listed launch MSRP.

Architecture Differences

Both CPUs share the same Zen 4 architecture, Raphael codename, 5 nm process node, and TSMC foundry. They also share the same memory support for DDR5, dual-channel memory bus, and 83.2 GB/s memory bandwidth. Both support ECC memory, PCIe Gen 5 with 24 lanes (CPU only), and integrated Radeon Graphics. Neither has an unlocked multiplier.

The core architectural difference beyond the core and thread counts is the L3 cache capacity. The 7800X3D has 96 MB of shared L3 cache, which is three times the 32 MB found on the 7645. This larger cache is likely a contributor to the 7800X3D’s strong PassMark results, particularly in data compression and physics, where larger working sets can fit in the cache. The 7645’s smaller 32 MB cache, combined with its higher boost clock, may explain its better Cinebench R23 performance, as that workload appears to favor higher clock speeds over larger cache.

The transistor count difference, 11,270 million versus 6,570 million, reflects the additional cores and larger cache on the 7800X3D, even though the die size is identical at 71 mm². Both are active production parts. The 7800X3D was released earlier, on 2023-01-03, while the 7645 followed on 2023-06-12. The market segment designation differs, with the 7800X3D aimed at Desktop and the 7645 at Server/Workstation, which may influence platform considerations despite the shared socket.

The data shows that architecture alone does not determine performance. The 7645, with fewer cores and less cache, still outpaces the 7800X3D in Cinebench R23 by significant margins. Meanwhile, the 7800X3D’s extra cores and larger cache deliver broad wins across the PassMark suite. Users should match their workload to the chip that wins the relevant tests.