AMD Ryzen 9 3900 vs AMD Ryzen 9 3900X Comparison

FAQ

Q: What is the core and thread count difference between the AMD Ryzen 9 3900 and the AMD Ryzen 9 3900X?

A: Both processors have 12 cores and 24 threads, so there is no difference in core or thread count.

Q: Which CPU has a higher boost clock?

A: The AMD Ryzen 9 3900X has a boost clock of 4.60 GHz, while the AMD Ryzen 9 3900 has a boost clock of 4.30 GHz.

Q: How much do the two CPUs differ in power consumption?

A: The AMD Ryzen 9 3900 has a TDP of 65 watts, whereas the AMD Ryzen 9 3900X has a TDP of 105 watts. That is a 40-watt difference in favor of the 3900.

Q: Which processor has a higher average benchmark score?

A: The AMD Ryzen 9 3900 has an average benchmark score of 47918, while the AMD Ryzen 9 3900X has an average benchmark score of 46487. The 3900 is higher by about 3.1%.

Q: In the head-to-head benchmark results, which CPU wins more tests?

A: The AMD Ryzen 9 3900X wins all 15 head-to-head benchmark comparisons. The AMD Ryzen 9 3900 wins none of them.

Q: Do both CPUs use the same socket and memory standard?

A: Yes, both use AMD Socket AM4 and support DDR4 memory with a dual-channel memory bus.

Architecture Differences

Both processors belong to the AMD 3000 series and are built on the Zen 2 architecture with the Matisse codename. They share the same 7 nm process node from TSMC, and both contain 7,600 million transistors on a dual-chiplet design with a die size of 2x 74 mm². The cache hierarchy is identical: 64 KB of L1 per core, 512 KB of L2 per core, and 64 MB of L3 cache. Neither processor includes integrated graphics.

The architectural differences are limited to clock speeds and power envelope. The AMD Ryzen 9 3900 runs at a base clock of 3.10 GHz and a boost clock of 4.30 GHz, while the AMD Ryzen 9 3900X runs at a base clock of 3.80 GHz and a boost clock of 4.60 GHz. This clock advantage is paired with a higher TDP: the 3900X is rated at 105 watts versus 65 watts for the 3900. Both chips support PCIe Gen 4 with 24 lanes (CPU only), and neither supports ECC memory. Memory bandwidth is 51.2 GB/s for both, and the memory bus is dual-channel DDR4. The multiplier is unlocked on both, so overclocking headroom exists for both parts, though the 3900X starts from a higher base.

The 3900X was released earlier, on 2019-07-06, while the 3900 came later on 2019-09-23. Both have the same launch MSRP of $499. The part numbers differ, with the 3900 listed as 100-000000070 and the 3900X as 100-000000023100-100000023BOX100-100000023MPK.

Head-to-Head Benchmarks

The head-to-head data is decisively one-sided. The AMD Ryzen 9 3900X wins every single benchmark comparison, with the largest margins appearing in multi-threaded and instruction-heavy workloads.

In Cinebench R15 multi-core, the 3900X scores 3049 against 2804 for the 3900, a delta of -8% (where the negative sign indicates the 3900 trails). Cinebench R15 single-core shows a smaller gap: 207 for the 3900X versus 197 for the 3900, a -4.8% difference. Geekbench multi-core amplifies the gap further, with the 3900X at 11948 and the 3900 at 10653, a -10.8% deficit for the 3900. Geekbench single-core is closer, at 1664 versus 1550, a -6.9% difference.

In PassMark workloads, the 3900X leads in every category. Data compression shows the 3900X at 448906 against 413887, a -7.8% gap. Data encryption sees 28586 versus 26657, a -6.7% difference. Extended instructions are a notable weak point for the 3900, with the 3900X scoring 29221 and the 3900 at 26073, a -10.8% deficit that matches the Geekbench multi-core margin. Find prime numbers shows 214 versus 203, a -5.1% gap. Floating point math is the closest contest, with 58434 against 56730, a -2.9% difference. Integer math is even tighter, at 99628 versus 97698, a -1.9% gap.

Multithread performance in PassMark shows 32544 for the 3900X versus 30586 for the 3900, a -6% difference. Physics is one of the larger margins, with 1794 versus 1617, a -9.9% gap. Random string sorting yields 48300 against 44902, a -7% difference. Single-thread PassMark scores are 2703 versus 2604, a -3.7% gap, and the same values appear for the passmark_singlethread test, confirming consistency.

The pattern is clear: the 3900X outperforms the 3900 across the board, but the magnitude varies. The biggest wins for the 3900X are in Geekbench multi-core and PassMark extended instructions, both at -10.8%. The smallest win is in PassMark integer math at -1.9%. This suggests that the 3900X's higher clock speeds translate most effectively into workloads that scale with frequency, while less clock-sensitive integer tasks see a smaller advantage.

Specification Differences

The following fields differ between the AMD Ryzen 9 3900 and the AMD Ryzen 9 3900X:

• Base Clock: 3.10 GHz (3900) vs 3.80 GHz (3900X)
• Boost Clock: 4.30 GHz (3900) vs 4.60 GHz (3900X)
• TDP: 65 W (3900) vs 105 W (3900X)
• Release Date: 2019-09-23 (3900) vs 2019-07-06 (3900X)
• Part Number: 100-000000070 (3900) vs 100-000000023100-100000023BOX100-100000023MPK (3900X)

All other measured specifications are identical: 12 cores, 24 threads, 7 nm process, 7,600 million transistors, 2x 74 mm² die size, 64 KB L1 per core, 512 KB L2 per core, 64 MB L3, DDR4 dual-channel memory, 51.2 GB/s bandwidth, no ECC support, PCIe Gen 4 with 24 lanes, no integrated graphics, desktop market segment, active production status, unlocked multiplier, and the same $499 launch MSRP.

The Verdict

The data is unambiguous: the AMD Ryzen 9 3900X is the faster processor in every recorded benchmark. It wins all 15 head-to-head comparisons, with margins ranging from -1.9% in PassMark integer math to -10.8% in Geekbench multi-core and PassMark extended instructions. The 3900X also carries a higher percentile ranking against all CPUs at 89, though the 3900 sits just above it at 90, a difference driven by the 3900's higher average benchmark score of 47918 versus 46487 for the 3900X.

That average score difference is worth noting. The 3900's average is pulled up by its nearest rivals in the database, which include the AMD Ryzen 9 7900X3D at 47908 (a 0% delta), the Intel Core Ultra 7 265T at 47697 (0.5% higher than the 3900), and the AMD Ryzen AI Max PRO 380 at 48171 (0.5% lower). The 3900X's nearest rivals are different: the Intel Xeon w3-2535 at 46653 (-0.4% relative to the 3900X), the AMD Ryzen 9 7845HX at 46654 (-0.4%), and the Intel Core i9-13900HX at 46098 (0.8% lower). So while the 3900X wins every direct comparison, the 3900 lands in a slightly higher average-score neighborhood in the broader database.

For a buyer choosing between these two, the decision hinges on the use case. If the priority is maximum performance in multi-threaded rendering, encryption, physics simulation, or any workload that benefits from the extra frequency, the 3900X is the clear pick. The -10.8% lead in Geekbench multi-core and extended instructions is substantial for two chips that share the same core count, cache, and architecture. The 3900X also wins single-thread tests by a consistent 3.7% to 6.9%, which matters for lightly threaded applications.

The 3900, on the other hand, offers the same 12-core, 24-thread configuration with a 65-watt TDP versus 105 watts for the 3900X. That is a 40-watt difference in power draw, which could be relevant for systems with tighter cooling or power budgets. The performance cost is real but not uniform: the 3900 trails by only 1.9% in integer math and 2.9% in floating-point math, meaning its efficiency is relatively better in those tasks. However, in workloads that scale with clock speed, the gap widens to nearly 11%.

Both processors launched at the same MSRP of $499, but that price is historical context, not a current purchasing guide. The recorded data shows a straightforward trade-off: the 3900X delivers more performance in every measured test at a higher power envelope, while the 3900 delivers slightly better average standing in the database with lower power consumption. For users who want the fastest possible Zen 2 12-core in this pair, the 3900X is the answer. For those who prioritize lower power draw and are willing to accept a 2% to 11% performance hit depending on the workload, the 3900 is the more efficient choice. There is no scenario in the benchmark data where the 3900 outperforms the 3900X, so the only reason to select it is power or thermal constraints.