AMD Ryzen 5 7640U vs AMD Ryzen 5 8640HS Comparison

The AMD Ryzen 5 8640HS and AMD Ryzen 5 7640U are two closely related mobile chips that split their head-to-head record in an unusual way. Both are six-core, twelve-thread Zen 4 processors built on TSMC's 4 nm process, and both sit in the 78th percentile of all CPUs tracked in the database. Yet the recorded results show the lower-TDP 7640U winning thirteen of seventeen shared benchmarks, including some by double-digit margins, while the 8640HS takes the remaining four contests. The average benchmark scores frame the gap: 26106 for the 8640HS against 25485 for the 7640U, a difference of well under one percent. This is a comparison where the aggregate numbers hide a split personality, and the details matter.

FAQ

Q: Which CPU wins more benchmarks in the database?

A: The Ryzen 5 7640U wins 13 of the 17 shared tests, while the Ryzen 5 8640HS wins 4. Despite that lopsided record, the 8640HS holds a slightly higher average benchmark score, 26106 versus 25485, because the tests it wins and the weightings differ across suites.

Q: Are these two chips architecturally different?

A: Only in codename and series label. Both use the Zen 4 architecture, 6 cores, 12 threads, a 3.50 GHz base clock, a 4.90 GHz boost clock, the same cache hierarchy, and the same 4 nm TSMC fabrication. The 8640HS is a Hawk Point part from the 8000 series; the 7640U is a Phoenix part from the 7000 series.

Q: What is the main specification difference?

A: The thermal design point. The 8640HS is rated at 28 watts and the 7640U at 15 watts. The 7640U also supports ECC memory, which the 8640HS does not. Their release dates differ as well.

Q: Which one is faster in Cinebench R23?

A: The 7640U, decisively. It scored 17936 in the multi-core test against 11486 for the 8640HS, a gap of 36 percent, and 2532 versus 1711 in single-core, a gap of 32.4 percent.

Q: Does the 8640HS win anything?

A: Yes. It leads in Cinebench R15 multi-core (1845 to 1807), Cinebench R15 single-core (268 to 255), and PassMark single-thread (3584 to 3524).

Q: How do they compare against rival CPUs?

A: The 8640HS sits within half a percent of chips like the Intel Core i7-14701TE and the Intel Core i9-11900KF. The 7640U is similarly bracketed by the AMD Ryzen 7 5700, AMD Ryzen 7 5825U, AMD Ryzen 7 7840U, and Intel Xeon D-2752TER, all within a fraction of a percent.

Architecture Differences

On paper, these two processors are nearly identical. Both are Zen 4 designs fabricated by TSMC on a 4 nm node, with 25,000 million transistors packed into a 178 mm² die. Both carry 6 cores and 12 threads, 64 KB of L1 cache per core, 1 MB of L2 cache per core, and 16 MB of shared L3 cache. Neither offers 3D V-Cache. The memory subsystems match too: DDR5 support, a dual-channel bus, 89.6 GB/s of bandwidth, and 20 lanes of PCIe Gen 4 from the CPU. Both chips integrate the same Radeon 760M graphics and fit Socket FP8, with FP7 and FP7r2 part numbers also listed for each.

The distinction is generational branding rather than silicon redesign. The 8640HS belongs to the 8000 series under the Hawk Point codename and was released in December 2023. The 7640U belongs to the 7000 series under the Phoenix codename and arrived in May 2023. Hawk Point is, in effect, a refresh of the Phoenix formula, and the database reflects that: identical clocks, identical cache, identical graphics, identical memory support. Given the shared DNA, the benchmark divergence between them is best explained by power envelope and platform behavior rather than architectural change. The 28-watt 8640HS has more thermal headroom on paper, yet the 15-watt 7640U posts many of the stronger scores, a result that suggests its samples in the database ran in configurations that extracted more sustained performance.

Head-to-Head Benchmarks

The Cinebench results tell two different stories depending on the version. In R15, the 8640HS leads in both tests: 1845 to 1807 in multi-core, a 2.1 percent edge, and 268 to 255 in single-core, a 5.1 percent edge. Switch to R23 and the picture inverts violently. The 7640U posts 17936 in multi-core against 11486 for the 8640HS, a 36 percent advantage, and 2532 versus 1711 in single-core, a 32.4 percent advantage. Gaps of that size between near-identical silicon indicate the recorded 8640HS samples were throttling or running in low-power configurations during sustained R23 loads, since a chip with the same cores and clocks should not trail by a third.

Geekbench also favors the 7640U, by 13.2 percent in multi-core (8595 to 7461) and 16.4 percent in single-core (2127 to 1778). The PassMark suite is more granular. The 7640U sweeps nearly everything: physics by 17 percent (1169 to 970), extended instructions by 6.8 percent (17019 to 15855), random string sorting by 7 percent (29382 to 27316), multithread by 5.8 percent (21115 to 19889), data encryption by 9.4 percent (14954 to 13551), data compression by 5.6 percent (240032 to 226544), integer math by 3.3 percent (70483 to 68173), floating point math by 3.3 percent (41093 to 39725), and prime finding (74 versus 70).

The 8640HS claws back the PassMark single-thread test, 3584 to 3524, a 1.7 percent win that echoes its R15 single-core lead. The pattern is consistent: in short, lightly loaded, single-threaded bursts the 8640HS matches or beats its sibling, but in longer and heavier workloads the recorded 7640U results pull far ahead.

Context against the wider database softens the drama. The 8640HS averages 26106, sitting 0.3 percent behind the AMD Ryzen 5 8540U, 0.4 percent ahead of the Intel Core i9-11900KF, 0.4 percent ahead of the Intel Core i7-14701TE, and 0.5 percent ahead of the AMD Ryzen AI 5 340. The 7640U averages 25485, within 0.2 percent of the AMD Ryzen 7 7825U-equivalent group: 0.1 percent behind the AMD Ryzen 7 5700, 0.2 percent behind the Intel Xeon D-2752TER, 0.2 percent ahead of the AMD Ryzen 7 7840U, and 0.2 percent ahead of the AMD Ryzen 7 5825U. Both chips land in the 78th percentile against all CPUs.

Specification Differences

The specification table is short because almost nothing differs. The TDP is the headline split: 28 watts for the 8640HS versus 15 watts for the 7640U. This is the one number that signals design intent, with the HS suffix denoting a higher-power mobile class and the U suffix denoting an efficiency-focused class.

ECC memory support is the other functional difference, and it favors the 7640U. The 7640U records ECC support as true, while the 8640HS records false, a meaningful distinction for workstation or reliability-sensitive mobile deployments even though both share identical DDR5 bandwidth and bus width.

Release date separates them by roughly seven months, the 7640U in May 2023 and the 8640HS in December 2023. Codename and series labels differ (Phoenix versus Hawk Point, 7000 series versus 8000 series). Everything else, cores, threads, clocks, cache, node, die size, transistor count, PCIe lanes, graphics, socket, and memory specification, is identical. Neither chip has an unlocked multiplier, both remain in active production, and neither has a recorded launch MSRP.

Where Each One Wins

The 8640HS wins where brief, bursty workloads dominate. Its victories all come in short tests: Cinebench R15 multi-core by 2.1 percent, R15 single-core by 5.1 percent, and PassMark single-thread by 1.7 percent. For tasks that finish quickly, such as opening heavy files, snappy compilation of small projects, or interface responsiveness, the recorded data shows the 8640HS holding a slim but real edge.

The 7640U owns sustained and parallel workloads. Its 36 percent Cinebench R23 multi-core lead, 32.4 percent single-core lead in the same suite, double-digit Geekbench advantages, and sweep of the PassMark physics, encryption, compression, integer, and floating point tests make it the stronger performer in the database for rendering, simulation, and sustained number crunching. It also delivers those results at half the TDP, and it adds ECC support for good measure.

The Verdict

Strictly on the recorded data, the Ryzen 5 7640U is the better all-round CPU in this database. It wins 13 of 17 shared benchmarks, including every sustained-load test, posts the higher Cinebench R23 and Geekbench scores by wide margins, does so at a 15-watt TDP, and uniquely offers ECC memory. Buyers prioritizing efficiency, sustained throughput, and memory reliability should pick the 7640U.

The 8640HS still has a case, but a narrow one. It leads in quick single-threaded and light multi-threaded bursts, holds a marginally higher average score of 26106, and its 28-watt envelope implies designs built to spend more power when the chassis allows. For snappy short-task performance, the data favors it. For everything else, the 7640U wins.