AMD Ryzen 7 PRO 7745 vs AMD Ryzen 9 3900 Comparison

The AMD Ryzen 7 PRO 7745 and the AMD Ryzen 9 3900 represent two distinct philosophies in processor design: one leverages a modern, efficient architecture with fewer cores, while the other relies on a higher core count from an older generation. The benchmark data shows a clear split, with the Ryzen 7 PRO 7745 winning 14 of the 17 head-to-head comparisons, while the Ryzen 9 3900 takes 3. The average benchmark scores are very close, with the Ryzen 9 3900 at 44039 and the Ryzen 7 PRO 7745 at 43704, a difference of -0.8% from the perspective of the Ryzen 7. This near-parity in overall average, despite the lopsided win count, highlights how the Ryzen 9 3900’s wins are in specific, heavily multithreaded tasks.

Head-to-Head Benchmarks

The most dramatic margin in the entire comparison is in single-threaded performance. In the PassMark single-thread test, the Ryzen 7 PRO 7745 scores 3849 against the Ryzen 9 3900’s 2604, a massive 47.8% advantage. This is not a subtle difference; it indicates a generational leap in per-core efficiency. The Cinebench R23 single-core test confirms this trend, with the Ryzen 7 PRO 7745 scoring 3935 versus 3669 for the Ryzen 9 3900, a 7.2% lead. The Ryzen 7 PRO 7745’s dominance extends to multi-core Cinebench tests, where it consistently leads by 7.3% in R15, R20, and R23 multicore benchmarks. In Cinebench R23 multicore, the Ryzen 7 PRO 7745 scores 27877, while the Ryzen 9 3900 trails at 25988. This result is particularly telling because the Ryzen 9 3900 has 12 cores and 24 threads, compared to the 8 cores and 16 threads of the Ryzen 7 PRO 7745, yet the newer processor still manages to win in this heavily threaded workload.

The Ryzen 7 PRO 7745 also shows clear superiority in several PassMark compute workloads. In extended instructions, it scores 29216 versus 26073 for the Ryzen 9 3900, a 12.1% advantage. Floating point math results show an 11.6% lead for the Ryzen 7 PRO 7745, with scores of 63332 and 56730 respectively. Integer math performance is also in favor of the Ryzen 7 PRO 7745, which scores 103330 against 97698, a 5.8% win. The PassMark multithread test shows a 7% lead for the Ryzen 7 PRO 7745, scoring 32733 versus 30586. Even in the physics test, the Ryzen 7 PRO 7745 wins with a score of 1699 compared to 1617, a 5.1% margin. Random string sorting favors the Ryzen 7 PRO 7745 as well, with a 4.1% lead (46759 vs 44902).

However, the Ryzen 9 3900 has its own victories, and they are not trivial. The largest win for the older processor is in the PassMark find prime numbers test, where it scores 203 against the Ryzen 7 PRO 7745’s 166, an 18.2% advantage. Data encryption is another strong point for the Ryzen 9 3900, which scores 26657 versus 22821 for the Ryzen 7 PRO 7745, a 14.4% lead. Finally, in data compression, the Ryzen 9 3900 wins with a score of 413887 compared to 386829 for the Ryzen 7 PRO 7745, a 6.5% margin. These three wins show that in specific, niche workloads, the additional cores of the Ryzen 9 3900 can still be leveraged effectively.

Where Each One Wins

The benchmark results paint a clear picture of where each processor excels. The Ryzen 7 PRO 7745 is the undisputed winner in general-purpose computing and single-threaded tasks. Its 47.8% lead in PassMark single-thread is a decisive factor for applications that rely on high per-core performance, such as everyday desktop responsiveness, office productivity, and lightly threaded applications. Its consistent 7.3% lead across all Cinebench multicore tests also demonstrates that it is a better choice for most rendering and video encoding workloads, even though it has fewer cores. The Ryzen 7 PRO 7745’s wins in extended instructions and floating point math suggest it is also better suited for scientific computing and financial modeling.

The Ryzen 9 3900, with its 12 cores, is the winner in a very specific set of tasks. Its 18.2% lead in prime number finding suggests an advantage in certain types of mathematical calculations. The 14.4% win in data encryption is notable for workloads involving heavy cryptography. The 6.5% lead in data compression indicates that archiving and decompression tasks may benefit from its higher core count. For a user whose workflow is dominated by these specific operations, the Ryzen 9 3900 offers a performance edge that the Ryzen 7 PRO 7745 cannot match. However, these wins are isolated; they do not translate to a broader performance advantage in standard benchmarks.

Architecture Differences

The two processors are built on fundamentally different architectures and platforms. The Ryzen 7 PRO 7745 is based on the Zen 4 architecture, codenamed Raphael, and is built on a 5 nm process at TSMC. It is a monolithic chip with 6,570 million transistors on a 71 mm² die. In contrast, the Ryzen 9 3900 is based on the older Zen 2 architecture, codenamed Matisse, and uses a 7 nm process. It is a chiplet design with two dies, each measuring 74 mm², and contains 7,600 million transistors. The Ryzen 7 PRO 7745 features 8 cores and 16 threads, while the Ryzen 9 3900 has 12 cores and 24 threads.

The cache configurations also differ significantly. Both have a 64 KB L1 cache per core and a 1 MB L2 cache per core, but the Ryzen 9 3900 has a larger 64 MB L3 cache compared to the 32 MB shared L3 cache on the Ryzen 7 PRO 7745. Memory support is a major differentiator: the Ryzen 7 PRO 7745 supports DDR5 memory with a dual-channel bus and a theoretical bandwidth of 83.2 GB/s, while the Ryzen 9 3900 uses DDR4 with a bandwidth of 51.2 GB/s. The Ryzen 7 PRO 7745 also supports ECC memory, while the Ryzen 9 3900 does not. The Ryzen 7 PRO 7745 is built for the AMD Socket AM5 and includes an integrated Radeon Graphics unit, whereas the Ryzen 9 3900 uses the AMD Socket AM4 and has no integrated graphics. The Ryzen 7 PRO 7745 supports PCIe Gen 5 with 24 lanes, while the Ryzen 9 3900 supports PCIe Gen 4. Clock speeds are also notably different, with the Ryzen 7 PRO 7745 having a base clock of 3.80 GHz and a boost clock of 5.30 GHz, compared to the Ryzen 9 3900’s 3.10 GHz base and 4.30 GHz boost. The Ryzen 9 3900 has an unlocked multiplier, while the Ryzen 7 PRO 7745’s multiplier is locked. The Ryzen 7 PRO 7745 is classified as a Server/Workstation part, while the Ryzen 9 3900 is a Desktop part.

The Verdict

The data strongly favors the AMD Ryzen 7 PRO 7745 for most users. Its 47.8% lead in single-threaded performance is the single most compelling statistic in this comparison. It is also faster in every Cinebench test, including multicore, despite having 4 fewer cores and 8 fewer threads. This means that for rendering, video editing, and most productivity applications, the Ryzen 7 PRO 7745 is the better choice. Its support for DDR5 memory and PCIe Gen 5 also make it a more future-proof platform. The Ryzen 7 PRO 7745’s integrated graphics is an added benefit for systems without a discrete GPU.

The AMD Ryzen 9 3900 remains a viable option only for a niche set of workloads. Its 18.2% lead in prime number finding and 14.4% lead in data encryption are significant for specific scientific or security-focused applications. Its 6.5% advantage in data compression could also be a deciding factor for users who perform constant archiving. However, these advantages are not enough to recommend it as a general-purpose processor. The Ryzen 9 3900’s launch MSRP was $499, and while it offers a greater core count, the architectural advantages of the Ryzen 7 PRO 7745 are overwhelming in the vast majority of benchmarks. The Ryzen 7 PRO 7745 is the superior processor for almost all tasks, with the Ryzen 9 3900 only being the right pick for a very specialized workflow that heavily weighs its three specific wins.

FAQ

Q: Which processor is better for single-threaded applications?

A: The AMD Ryzen 7 PRO 7745 is significantly better, with a 47.8% higher score in the PassMark single-thread test (3849 vs 2604) and a 7.2% higher score in Cinebench R23 single-core (3935 vs 3669).

Q: Does the Ryzen 9 3900’s higher core count make it faster in multi-core workloads?

A: No. Despite having 12 cores and 24 threads versus the Ryzen 7 PRO 7745’s 8 cores and 16 threads, the Ryzen 7 PRO 7745 wins all multi-core Cinebench tests by 7.3% and the PassMark multithread test by 7%.

Q: In which benchmark does the Ryzen 9 3900 have its largest advantage?

A: The Ryzen 9 3900’s largest win is in the PassMark find prime numbers test, where it scores 203 versus 166 for the Ryzen 7 PRO 7745, an 18.2% advantage.

Q: What are the memory type differences between the two CPUs?

A: The Ryzen 7 PRO 7745 supports DDR5 memory with a bandwidth of 83.2 GB/s, while the Ryzen 9 3900 supports DDR4 memory with a bandwidth of 51.2 GB/s. The Ryzen 7 PRO 7745 also supports ECC memory, which the Ryzen 9 3900 does not.

Q: Do both processors have integrated graphics?

A: No. The AMD Ryzen 7 PRO 7745 includes Radeon Graphics, while the AMD Ryzen 9 3900 does not have an integrated GPU.

Q: Which processor has a higher boost clock?

A: The AMD Ryzen 7 PRO 7745 has a higher boost clock of 5.30 GHz, compared to the AMD Ryzen 9 3900’s boost clock of 4.30 GHz.