AMD Ryzen 5 240 vs AMD Ryzen 9 3900XT Comparison

The AMD Ryzen 9 3900XT and AMD Ryzen 5 240 represent two very different philosophies: a high-core-count desktop processor from 2020 and a modern, efficient mobile chip from 2025. The benchmark data paints a clear, lopsided picture, with the older desktop part dominating multi-threaded workloads while the newer mobile chip takes a decisive win in single-thread performance.

Head-to-Head Benchmarks

The Ryzen 9 3900XT wins 13 of the 15 head-to-head comparisons, and the margins are often substantial. In Cinebench R23 multi-core, the 3900XT scores 27,688 against the Ryzen 5 240’s 13,013, a 112.8% advantage. This is the largest multi-threaded gap in the data, driven by the 3900XT’s 12 cores and 24 threads versus the 240’s 6 cores and 12 threads. The Cinebench R15 multi-core test shows a similar but smaller lead: 2,790 vs 2,078, a 34.3% difference.

The 3900XT also wins heavily in PassMark’s integer and floating-point math tests. Integer math shows 99,722 vs 73,189, a 36.3% lead, while floating-point math is 58,513 vs 45,301, a 29.2% advantage. The data compression test is even more pronounced: 452,328 vs 267,963, a 68.8% difference. Encryption workloads favor the 3900XT by 80.7% (28,634 vs 15,849). The PassMark multi-thread score is 32,575 vs 22,658, a 43.8% lead.

The most extreme delta appears in the PassMark find prime numbers test. The 3900XT scores 214, while the Ryzen 5 240 scores only 70, giving the desktop chip a 205.7% advantage. This test is highly sensitive to core count and memory bandwidth, both of which favor the 3900XT. Physics simulation also strongly favors the 3900XT: 1,776 vs 1,060, a 67.5% gap.

The only two wins for the Ryzen 5 240 come in the PassMark single-thread tests. The 240 scores 3,675 in both PassMark single_thread and singlethread, while the 3900XT scores 2,742. This is a 25.4% advantage for the mobile chip. This is a significant margin, reflecting the 240’s higher boost clock (5.00 GHz vs 4.70 GHz) and its newer Zen 4 architecture. However, this single-thread win does not translate to other single-core benchmarks in the data, as the 3900XT wins Cinebench R15 single-core (393 vs 270, a 45.6% lead) and Cinebench R23 single-core (3,909 vs 1,742, a 124.4% lead). The Cinebench results are surprising given the 240’s clock advantage, but the 3900XT’s larger L3 cache (64 MB vs 16 MB) and higher TDP likely contribute to its single-core dominance in those specific tests.

FAQ

Q: Which processor has the higher average benchmark score?

A: The Ryzen 9 3900XT has an average benchmark score of 33,736, while the Ryzen 5 240 has an average of 33,542. Both are in the 84th percentile of all CPUs, making them statistically close in overall performance.

Q: How does the Ryzen 9 3900XT compare to its nearest rivals?

A: The 3900XT’s nearest rival is the AMD Ryzen 5 7645HX with an average score of 33,668 (0.2% higher). It also sits near the AMD Ryzen 7 8840HS (33,667, 0.2% higher) and slightly above the Intel Xeon 6353P (33,844, -0.3% lower) and Intel Core i7-12800HX (33,875, -0.4% lower).

Q: What is the largest single benchmark margin between the two CPUs?

A: The largest margin is in the PassMark find prime numbers test, where the Ryzen 9 3900XT leads by 205.7% (214 vs 70). The second-largest is Cinebench R23 multi-core at 112.8%.

Q: Does the Ryzen 5 240 win any benchmark by a wide margin?

A: Yes, the Ryzen 5 240 wins both PassMark single-thread tests by 25.4% (3,675 vs 2,742). This is its only clear area of superiority, and it does not appear in the Cinebench single-core tests.

Q: Which CPU has a higher boost clock, and does it matter?

A: The Ryzen 5 240 has a boost clock of 5.00 GHz, while the Ryzen 9 3900XT boosts to 4.70 GHz. The higher clock likely explains the 240’s PassMark single-thread win, but the 3900XT still wins Cinebench single-core tests by large margins.

Q: Are both processors in the same market segment?

A: No. The Ryzen 9 3900XT is a Desktop processor, while the Ryzen 5 240 is a Mobile processor. This explains the differences in socket, TDP, and integrated graphics.

The Verdict

The data is unambiguous for multi-threaded workloads: the Ryzen 9 3900XT is the clear choice. It wins 13 of 15 benchmarks, and its leads in Cinebench R23 multi-core (112.8%), PassMark data compression (68.8%), and PassMark encryption (80.7%) are decisive. Users who render, compile, encode, or run heavy scientific workloads should pick the 3900XT. Its 12 cores and 24 threads provide a level of parallel throughput that the 6-core, 12-thread Ryzen 5 240 cannot match.

The Ryzen 5 240 is the choice only for workloads that are strictly single-threaded and short-lived. Its 25.4% lead in PassMark single-thread tests is real, but it is a narrow advantage in a narrow domain. For any mixed workload, the 3900XT’s multi-core dominance outweighs its single-thread deficit. The 3900XT also wins Cinebench R23 single-core by 124.4%, so the 240’s single-thread advantage does not even hold across all single-thread benchmarks.

The 3900XT’s percentile ranking (84th) is identical to the 240’s, and their average benchmark scores are within 0.6% of each other (33,736 vs 33,542). This suggests that for the average user, the two CPUs are roughly comparable. However, the distribution of wins matters: the 3900XT wins by large margins in the tests that dominate average scores, while the 240 wins by a modest margin in two tests. Therefore, the 3900XT is the better overall performer for most applications.

Specification Differences

The two CPUs differ in nearly every fundamental specification. The Ryzen 9 3900XT has 12 cores and 24 threads, while the Ryzen 5 240 has 6 cores and 12 threads. Base clocks are 3.90 GHz for the 3900XT and 4.30 GHz for the 240; boost clocks are 4.70 GHz and 5.00 GHz, respectively. The TDP is 105 W for the desktop chip and 45 W for the mobile chip.

The 3900XT uses the AMD Socket AM4, while the 240 uses AMD Socket FP8. The 3900XT is based on Zen 2 architecture (codename Matisse 2), and the 240 is based on Zen 4 (codename Hawk Point). The process node differs: 7 nm for the 3900XT versus 4 nm for the 240, both fabricated by TSMC.

Cache configurations are distinct. The 3900XT has 64 KB L1 per core, 512 KB L2 per core, and 64 MB L3. The 240 has 64 KB L1 per core, 1 MB L2 per core, and 16 MB L3 (shared). Memory support differs: the 3900XT uses DDR4 with dual-channel memory and 51.2 GB/s bandwidth, while the 240 uses DDR5 with dual-channel memory and 89.6 GB/s bandwidth.

PCIe lanes are Gen 4 for both, but the 3900XT has 24 lanes (CPU only) versus 20 lanes for the 240. The 240 includes integrated Radeon 760M graphics, while the 3900XT has no integrated graphics. The 3900XT has an unlocked multiplier; the 240 does not. Transistor counts are 7,600 million for the 3900XT and 25,000 million for the 240. Die size is 2x 74 mm² for the 3900XT and 178 mm² for the 240. The 3900XT launched on 2020-07-06 with a launch MSRP of $499; the 240 launched on 2025-01-05 with no launch MSRP listed.

Where Each One Wins

The Ryzen 9 3900XT wins in every multi-threaded and most single-threaded scenarios. Its 12-core configuration gives it a 112.8% lead in Cinebench R23 multi-core and a 205.7% lead in prime number finding. It is also 68.8% faster in data compression, 80.7% faster in encryption, and 43.8% faster in PassMark multi-thread. For rendering, scientific computing, video encoding, and heavy multitasking, the 3900XT is the superior part.

The Ryzen 5 240 wins in PassMark single-thread tests by 25.4%. This makes it the better choice for legacy or poorly threaded applications that rely on a single core, such as certain older games or simple office tasks. Its higher boost clock (5.00 GHz) and newer Zen 4 architecture contribute to this advantage. However, the 3900XT still wins Cinebench single-core tests by 45.6% (R15) and 124.4% (R23), so the 240’s single-thread win is not universal.

The 240 also has a lower TDP (45 W vs 105 W) and integrated graphics, making it suitable for slim laptops where battery life and compact design matter. But in raw performance benchmarks, the 3900XT is ahead in 13 of 15 tests.

Architecture Differences

The architectural gap between the two is significant. The Ryzen 9 3900XT uses Zen 2 on a 7 nm process, with a chiplet design indicated by its 2x 74 mm² die size. It has 7,600 million transistors and a 64 MB L3 cache. The Ryzen 5 240 uses Zen 4 on a 4 nm process, with a monolithic 178 mm² die and 25,000 million transistors. The 240’s L3 cache is 16 MB, which is one-quarter the size of the 3900XT’s.

The 240’s Zen 4 architecture brings higher clock speeds (4.30 GHz base, 5.00 GHz boost) and supports DDR5 memory with 89.6 GB/s bandwidth, versus DDR4 at 51.2 GB/s for the 3900XT. The 240 also integrates Radeon 760M graphics, which the 3900XT lacks. The 240’s L2 cache is larger per core (1 MB vs 512 KB), which helps with single-thread performance.

The 3900XT’s advantage lies in its core count and massive L3 cache. The 64 MB L3 is four times larger than the 240’s 16 MB, which is critical for multi-threaded workloads that share data. The 3900XT also has 24 PCIe Gen 4 lanes versus 20 for the 240, allowing more expansion devices. The 240’s 4 nm process gives it a power efficiency advantage, but the 3900XT’s 105 W TDP allows it to sustain higher multi-core performance over long workloads. The 3900XT is unlocked for overclocking, while the 240 is locked. These architectural differences explain the benchmark results: more cores and cache win multi-threaded tests, while higher clocks and newer IPC win some single-thread tests.