AMD Ryzen 5 8640U vs Intel Core i9-9900K Comparison

Head-to-Head Benchmarks

The head-to-head data presents a fascinating split: the Intel Core i9-9900K wins 7 tests, while the AMD Ryzen 5 8640U wins 10. The victories are not evenly distributed; they cluster around different workload types, revealing distinct performance personalities.

The Intel chip’s most decisive triumph comes in Cinebench R23 multi-core, where it scores 15333 against the AMD’s 10433, a commanding 47% advantage. This is echoed in Cinebench R23 single-core, where Intel leads 2164 to 1651, a 31.1% margin. The Geekbench multi-core test also favors Intel, with a 9276 to 8185 result, a 13.3% lead. In data compression, Intel’s 283506 score beats AMD’s 230080 by 23.2%, and in random string sorting, Intel wins 36238 to 28066, a 29.1% gap. The extended instructions test sees Intel ahead 18965 to 16500, a 14.9% difference, and floating point math is a narrow Intel win at 41036 versus 40330, just 1.8%.

The AMD Ryzen 5 8640U counters with equally striking wins in other areas. Its most dramatic victory is in data encryption: 14013 versus Intel’s 6430, a 54.1% advantage. The single-thread tests strongly favor AMD, with PassMark single-thread showing 3534 versus 2919, a 17.4% lead, and Geekbench single-core at 2131 versus 1681, a 21.1% margin. Cinebench R15 sees AMD ahead in both multi-core (1663 to 1545, 7.1%) and single-core (256 to 217, 15.2%). Prime number finding is also an AMD win, 69 to 47, a 31.9% advantage. The multithread test goes to AMD at 20322 versus 18153, a 10.7% lead, and physics simulation favors AMD 1033 to 934, a 9.6% margin. Integer math is close but goes AMD’s way, 68051 to 66134, a 2.8% difference.

These results tell a clear story. Intel’s older architecture retains dominance in sustained multi-core rendering and memory-heavy operations like compression and sorting. AMD’s newer design excels at encryption, single-thread responsiveness, and integer-heavy tasks.

Where Each One Wins

The benchmark split suggests distinct use-case strengths. For content creation workloads that rely on multi-core rendering, the Intel Core i9-9900K is the clear pick. The 47% lead in Cinebench R23 multi-core indicates that tasks like 3D scene rendering or video encoding, which scale across cores and threads, will complete substantially faster on the Intel chip. Its 13.3% Geekbench multi-core advantage reinforces this pattern. Data compression and random string sorting, common in database operations and file archiving, also strongly favor Intel with margins of 23.2% and 29.1% respectively.

The AMD Ryzen 5 8640U, despite having fewer cores and threads, wins in scenarios that reward per-core efficiency and modern instruction sets. The 54.1% encryption advantage is striking; this points to hardware-accelerated cryptography or more efficient AES execution. The single-thread wins across Geekbench (21.1%), PassMark (17.4%), and Cinebench R15 (15.2%) suggest that everyday desktop responsiveness, light coding, and office productivity favor AMD. The integer math win, though narrow at 2.8%, plus the 31.9% lead in prime number finding, indicates AMD’s Zen 4 cores handle algorithmic and computational logic tasks more efficiently. The multithread test, which AMD wins by 10.7% despite lower core count, further suggests that AMD’s thread scheduling and per-core throughput are superior in mixed workloads.

For a laptop chip, the AMD’s wins in encryption and single-thread performance align well with mobile use cases like secure browsing, spreadsheet calculations, and responsive app switching. The Intel chip’s wins align with desktop scenarios where rendering time and batch processing matter more.

Architecture Differences

The two processors come from fundamentally different eras and design philosophies. The Intel Core i9-9900K uses the Coffee Lake architecture, specifically Coffee Lake-R, built on Intel’s 14 nm process. It packs 8 cores and 16 threads, with a base clock of 3.60 GHz and boost clock of 5.00 GHz. The die size is 180.3 mm². Its cache layout includes 64 KB L1 per core, 256 KB L2 per core, and 16 MB shared L3. The memory support is DDR4 with dual-channel access and 42.7 GB/s bandwidth. PCIe is Gen 3 with 16 lanes from the CPU. The integrated graphics are UHD Graphics 630. It fits the Intel Socket 1151 and carries a 95 W TDP.

The AMD Ryzen 5 8640U belongs to the Zen 4 family, codenamed Hawk Point, built on TSMC’s 4 nm process. It has 6 cores and 12 threads, with a base clock of 3.50 GHz and boost clock of 4.90 GHz. The die size is 178 mm², and the transistor count is listed at 25,000 million. The cache hierarchy differs notably: L1 is identical at 64 KB per core, but L2 doubles to 1 MB per core, while L3 remains 16 MB shared. Memory support is DDR5 with dual-channel access and a substantially higher 89.6 GB/s bandwidth. PCIe is Gen 4 with 20 lanes. The integrated graphics are Radeon 760M. It uses AMD Socket FP8 and has a much lower 28 W TDP.

The process node difference is the most fundamental architectural gap: 14 nm versus 4 nm. This explains the AMD chip’s ability to deliver competitive or superior performance in many tests while drawing only 28 W versus 95 W. The larger L2 cache per core on AMD (1 MB versus 256 KB) likely contributes to its single-thread and integer math advantages. The DDR5 memory support and higher bandwidth (89.6 GB/s versus 42.7 GB/s) explain AMD’s encryption and data throughput wins. The PCIe Gen 4 with 20 lanes versus Gen 3 with 16 lanes also reflects the generational gap.

Specification Differences

The recorded specifications show clear divergences. The core count differs: Intel has 8 cores and 16 threads, AMD has 6 cores and 12 threads. Base clocks are close (3.60 GHz versus 3.50 GHz), as are boost clocks (5.00 GHz versus 4.90 GHz), but the TDP is starkly different: 95 W versus 28 W. The socket differs: Intel Socket 1151 versus AMD Socket FP8. The process node is 14 nm versus 4 nm, with foundries Intel versus TSMC. Die size is nearly identical (180.3 mm² versus 178 mm²), but transistor count is only listed for AMD at 25,000 million.

Cache specifications differ in L2: 256 KB per core for Intel versus 1 MB per core for AMD. L1 and L3 are identical in size. Memory support is DDR4 versus DDR5, with bandwidth 42.7 GB/s versus 89.6 GB/s. PCIe generation and lane count differ: Gen 3 with 16 lanes versus Gen 4 with 20 lanes. Integrated graphics are UHD Graphics 630 versus Radeon 760M. The market segment is Desktop versus Mobile. Production status is End-of-life versus Active. Release dates are 2018-10-18 versus 2023-12-05. The Intel part has a launch MSRP of $488, while the AMD has no listed launch MSRP. The Intel multiplier is unlocked, while AMD’s is locked. The AMD part lists multiple part numbers for different socket variants (FP7r2, FP7, FP8).

FAQ

Q: Which processor is faster in Cinebench R23 multi-core, and by how much?

A: The Intel Core i9-9900K is faster, scoring 15333 versus AMD’s 10433, a 47% advantage.

Q: Does the AMD Ryzen 5 8640U win any Cinebench tests?

A: Yes, in Cinebench R15, AMD wins both multi-core (1663 to 1545, 7.1%) and single-core (256 to 217, 15.2%).

Q: How do the two compare in encryption performance?

A: The AMD Ryzen 5 8640U wins decisively, scoring 14013 versus Intel’s 6430 in PassMark data encryption, a 54.1% margin.

Q: Which chip has higher memory bandwidth?

A: The AMD Ryzen 5 8640U supports DDR5 with 89.6 GB/s bandwidth, while the Intel Core i9-9900K supports DDR4 with 42.7 GB/s.

Q: What are the core and thread counts for each?

A: The Intel has 8 cores and 16 threads. The AMD has 6 cores and 12 threads.

Q: Which processor has a higher boost clock?

A: The Intel Core i9-9900K has a boost clock of 5.00 GHz, slightly above the AMD’s 4.90 GHz.

The Verdict

The data paints a clear picture of two processors built for different environments. The Intel Core i9-9900K is a desktop part with an unlocked multiplier, designed for high-power scenarios where its 95 W TDP is acceptable. Its wins in Cinebench R23 multi-core (47%), data compression (23.2%), and random string sorting (29.1%) make it the choice for users whose primary workloads are multi-threaded rendering, file compression, and sort-heavy data processing. Its 79th percentile ranking versus all CPUs, with an average benchmark score of 27097, places it near rivals like the AMD Ryzen 7 5700G (27051, 0.2% delta) and Intel Core i5-14400T (27166, -0.3% delta), confirming it remains competitive in its niche.

The AMD Ryzen 5 8640U, a mobile part with a locked multiplier and 28 W TDP, is the better pick for portable computing. Its wins in encryption (54.1%), single-thread tests (Geekbench 21.1%, PassMark 17.4%), and integer math (2.8%) indicate superior per-core efficiency and modern instruction handling. Its 78th percentile ranking, with an average score of 26462, sits near the Intel Core i9-12900HK (26469, 0% delta) and Intel Core i7-1280P (26469, 0% delta), showing it matches high-end mobile chips.

For a desktop user building a dedicated workstation for CPU-heavy rendering, the Intel chip’s 47% multi-core lead is decisive. For a laptop user needing strong single-thread responsiveness, hardware-accelerated encryption, and efficient power usage, the AMD chip is the logical choice. The benchmark data does not suggest one is universally superior; it suggests the Intel wins where raw core count and sustained multi-threading matter, while the AMD wins where modern architecture, cache efficiency, and per-core speed dominate. The choice depends entirely on the target platform and workload mix.