AMD Ryzen 5 PRO 8540U vs AMD Ryzen 7 8840U Comparison

The AMD Ryzen 7 8840U and AMD Ryzen 5 PRO 8540U are both 28W mobile processors built on the Zen 4 architecture, but they are positioned for different workloads. The 8840U is the clear multi-threaded workhorse, winning 11 of 15 head-to-head benchmark comparisons, while the 8540U takes a surprising lead in specific single-threaded and newer Cinebench tests. The data shows two distinct personalities: one for heavy parallel tasks and one for lightly-threaded responsiveness.

Where Each One Wins

The AMD Ryzen 7 8840U dominates in almost every PassMark workload and in the older Cinebench R15 suite. Its advantage is most pronounced in integer math, where it scores 85,740 versus the 8540U’s 56,738, a 51.1% lead. Floating point math shows a similar story: 48,820 versus 34,865, a 40% advantage. Data compression and encryption also go strongly to the 8840U, with 30.1% and 30.5% deltas respectively. This is a processor built for sustained, multi-threaded number crunching, content creation, and any task that can use all 8 cores and 16 threads.

The AMD Ryzen 5 PRO 8540U wins in Cinebench R23 (both multi-core and single-core) and in the PassMark single-thread test. The R23 results are notable: the 8540U scores 15,456 multi-core versus the 8840U’s 12,972, a 16.1% swing in its favor. This is counterintuitive given the 8840U’s extra cores, but the data is clear. In single-core R23, the 8540U also leads by 22% (2,182 versus 1,703). However, its PassMark single-thread win is razor-thin: 3,563 versus 3,543, a 0.6% edge.

The practical split is simple. For rendering, compiling, scientific computing, or any workload that scales across cores, the 8840U is the pick. For bursty, single-threaded tasks like application loading, spreadsheet recalculations, or older software that prefers high clock speeds, the 8540U shows surprising competence, especially in the newer Cinebench version.

The Verdict

Choose the AMD Ryzen 7 8840U if your priority is maximum parallel performance. It has 8 cores and 16 threads, and it leads in 11 of the 15 benchmark comparisons. The data shows it is 28.1% ahead in PassMark multithread and 30% ahead in Cinebench R15 multi-core. It also carries the faster Radeon 780M integrated graphics versus the 8540U’s Radeon 740M, making it the better choice for any light gaming or GPU-accelerated tasks without a discrete card.

Choose the AMD Ryzen 5 PRO 8540U if you value single-thread responsiveness and use software that favors newer benchmark optimizations. Its Cinebench R23 wins are substantial (22% in single-core, 16.1% in multi-core), and it edges out the 8840U in PassMark single-thread. The 8540U also supports ECC memory, which the 8840U does not, making it relevant for data-integrity-focused mobile workstations. Both chips sit at the 76th percentile of all CPUs, and their average benchmark scores are nearly identical (23,982 for the 8840U vs 23,709 for the 8540U), so neither is a bad choice.

The verdict is workload-dependent. The 8840U is for raw throughput. The 8540U is for efficiency in single-threaded tasks and for users who need ECC memory support.

Head-to-Head Benchmarks

The largest victory for the AMD Ryzen 7 8840U comes in PassMark integer math, where it scores 85,740 against 56,738 for the 8540U. That 51.1% delta is the biggest gap in the entire comparison. Floating point math follows closely, with the 8840U’s 48,820 beating 34,865 by 40%. These two results alone suggest that the 8840U has significantly more processing muscle for complex calculations.

The 8840U also wins PassMark data encryption by 30.5% (16,072 vs 12,319) and data compression by 30.1% (267,525 vs 205,703). In Cinebench R15 multi-core, it scores 2,024 versus 1,557, a 30% lead. PassMark multithread shows a 28.1% advantage (23,346 vs 18,218). Random string sorting also goes to the 8840U by 29.7% (32,158 vs 24,797). Extended instructions favor the 8840U by 21.1%, and find prime numbers by 18.2%. PassMark physics shows a 19.6% lead for the 8840U (1,176 vs 983). Every one of these 11 wins is substantial, with most exceeding 20%.

The AMD Ryzen 5 PRO 8540U’s wins are fewer but significant. Its Cinebench R23 multi-core score of 15,456 beats the 8840U’s 12,972 by 16.1%. Single-core R23 is an even bigger margin: 2,182 versus 1,703, a 22% lead. The PassMark single-thread test goes to the 8540U by a negligible 0.6% (3,563 vs 3,543). These results are puzzling because the 8840U wins the older Cinebench R15 single-core test by 21.5% (266 vs 219). The discrepancy suggests that the 8540U’s architecture or firmware handles the newer R23 workload more efficiently, even with a lower 4.90 GHz boost clock versus the 8840U’s 5.10 GHz.

FAQ

Q: Which CPU has more cores and threads?

A: The AMD Ryzen 7 8840U has 8 cores and 16 threads. The AMD Ryzen 5 PRO 8540U has 6 cores and 12 threads.

Q: Does the Ryzen 7 8840U win every benchmark?

A: No. The 8840U wins 11 of 15 head-to-head tests, but the 8540U wins Cinebench R23 multi-core, Cinebench R23 single-core, and the PassMark single-thread test.

Q: Is the Ryzen 5 PRO 8540U faster in single-core performance?

A: It depends on the test. The 8540U wins PassMark single-thread by 0.6% (3,563 vs 3,543) and Cinebench R23 single-core by 22% (2,182 vs 1,703). However, the 8840U wins Cinebench R15 single-core by 21.5% (266 vs 219).

Q: Which CPU has better integrated graphics?

A: The AMD Ryzen 7 8840U comes with Radeon 780M graphics. The AMD Ryzen 5 PRO 8540U has Radeon 740M graphics.

Q: Do both CPUs support ECC memory?

A: No. The AMD Ryzen 5 PRO 8540U supports ECC memory. The AMD Ryzen 7 8840U does not.

Q: What is the average benchmark score difference between them?

A: The 8840U has an average benchmark score of 23,982, while the 8540U scores 23,709. The 8540U is 1.1% behind the 8840U in the nearestRivals comparison.

Architecture Differences

Both processors are built on the same AMD Zen 4 architecture and share the Hawk Point codename, but they are not identically implemented. The Ryzen 7 8840U uses 8 cores and 16 threads, while the Ryzen 5 PRO 8540U uses 6 cores and 12 threads. Both are manufactured by TSMC on a 4nm process node, but the die sizes differ: the 8840U has a 178 mm² die with 25,000 million transistors, while the 8540U has a 137 mm² die with 20,900 million transistors.

The cache hierarchy is the same per core: 64 KB of L1 and 1 MB of L2, with 16 MB of shared L3 on both chips. However, the total number of cores means the 8840U has more aggregate L2 cache (8 MB vs 6 MB). The integrated graphics differ significantly: the 8840U features the Radeon 780M, while the 8540U has the Radeon 740M. The 8540U uniquely supports ECC memory, a feature absent on the 8840U.

The 8840U uses AMD Socket FP8, while the 8540U uses AMD Socket FP7. This means they are not socket-compatible, despite both being mobile processors. The 8840U also has more PCIe lanes: 20 lanes (CPU only) versus 14 lanes on the 8540U. Both are Zen 4 parts, but the 8840U is a larger, more fully-featured chip with higher core counts and a more capable iGPU.

Specification Differences

The two CPUs differ in several key specifications. The AMD Ryzen 7 8840U has a base clock of 3.30 GHz and a boost clock of 5.10 GHz, while the AMD Ryzen 5 PRO 8540U has a base clock of 3.20 GHz and a boost clock of 4.90 GHz. Both have a TDP of 28 watts.

The 8840U has 8 cores and 16 threads, while the 8540U has 6 cores and 12 threads. The 8840U uses AMD Socket FP8, and the 8540U uses AMD Socket FP7. The 8840U has 25,000 million transistors on a 178 mm² die, while the 8540U has 20,900 million transistors on a 137 mm² die.

The integrated graphics differ: Radeon 780M on the 8840U versus Radeon 740M on the 8540U. The 8840U supports PCIe Gen 4 with 20 lanes (CPU only), while the 8540U supports Gen 4 with 14 lanes. The 8540U supports ECC memory, but the 8840U does not. Both support DDR5 memory with dual-channel buses and identical 89.6 GB/s memory bandwidth.

The release dates differ: the 8840U launched on 2023-12-05, while the 8540U launched on 2024-04-15. Both have locked multipliers. The 8840U has part numbers 100-000001323(FP7r2), 100-000001375(FP7), and 100-000001312(FP8), while the 8540U has 100-000001329(FP7r2) and 100-000001331(FP7). Neither has a launch MSRP listed.