AMD Ryzen 7 3800X vs Intel Core Ultra 5 135H Comparison

The AMD Ryzen 7 3800X and Intel Core Ultra 5 135H represent two very different philosophies in processor design: a high-power desktop part built for sustained throughput versus a low-power mobile chip engineered for efficiency and integration. The benchmark data shows a clear split: the Ryzen 7 3800X dominates in most multi-threaded and legacy single-thread workloads, while the Core Ultra 5 135H counters with decisive wins in specific math and physics tests. Both processors sit at the 81st percentile among all CPUs, indicating they are broadly comparable in overall performance tier, yet their individual strengths are sharply divergent.

FAQ

Q: Which processor has more cores and threads?

A: The Intel Core Ultra 5 135H has 14 cores and 18 threads, compared to the AMD Ryzen 7 3800X’s 8 cores and 16 threads.

Q: How do they compare in Cinebench R23 multi-core performance?

A: The AMD Ryzen 7 3800X scores 19,588, which is 64.9% higher than the Intel Core Ultra 5 135H’s 11,875.5.

Q: Which CPU wins in PassMark single-thread performance?

A: The Intel Core Ultra 5 135H wins decisively, scoring 3,521 versus the AMD Ryzen 7 3800X’s 2,712, a 23% advantage.

Q: What is the TDP difference between the two?

A: The AMD Ryzen 7 3800X has a TDP of 105 watts, while the Intel Core Ultra 5 135H has a TDP of 28 watts.

Q: Do both processors support ECC memory?

A: No, neither the AMD Ryzen 7 3800X nor the Intel Core Ultra 5 135H supports ECC memory.

Q: Which CPU has a higher boost clock?

A: The Intel Core Ultra 5 135H has a slightly higher boost clock of 4.60 GHz compared to the AMD Ryzen 7 3800X’s 4.50 GHz.

Architecture Differences

The fundamental architectural divergence begins with the process node and foundry. The AMD Ryzen 7 3800X is built on a 7 nm process at TSMC, incorporating 3,800 million transistors on a 74 mm² die. The Intel Core Ultra 5 135H also uses a 7 nm node but is manufactured by Intel, and its transistor count and die size are not listed. This leads to different core configurations: the Ryzen 7 3800X uses 8 cores and 16 threads based on the Zen 2 (Matisse) architecture, while the Core Ultra 5 135H uses 14 cores and 18 threads based on the Meteor Lake architecture.

Cache hierarchies are markedly different. The Ryzen 7 3800X has 64 KB of L1 cache per core and 512 KB of L2 cache per core, with a large 32 MB L3 cache. The Core Ultra 5 135H has 112 KB of L1 cache per core and a much larger 2 MB of L2 cache per core, but its L3 cache is significantly smaller at 18 MB shared. This suggests the Intel design relies more on per-core cache for its hybrid architecture, while the AMD design uses a larger shared pool.

Memory support and I/O capabilities also diverge sharply. The Ryzen 7 3800X supports DDR4 memory with dual-channel configuration and a memory bandwidth of 51.2 GB/s, along with PCIe Gen 4 with 24 lanes (CPU only). The Core Ultra 5 135H supports DDR5 memory (dependent on motherboard), also dual-channel, but offers a much higher memory bandwidth of 89.6 GB/s and PCIe Gen 5 with 8 lanes (CPU only). The Intel chip also includes integrated graphics (Arc Xe-LPG 96EU), while the AMD desktop part has none.

Socket and market positioning are equally distinct. The Ryzen 7 3800X uses AMD Socket AM4, targets the desktop segment, and has an unlocked multiplier. The Core Ultra 5 135H uses Intel BGA 2049, targets the mobile segment, and has a locked multiplier. Their release dates are separated by over four years, with the AMD part launching on 2019-07-06 and the Intel part on 2023-12-13.

Head-to-Head Benchmarks

The AMD Ryzen 7 3800X wins 12 of the 17 head-to-head benchmark comparisons, and its victories are often overwhelming. The most dramatic result is in Cinebench R23 multi-core, where the Ryzen 7 3800X scores 19,588 against the Core Ultra 5 135H’s 11,875.5, a massive 64.9% lead. Single-core performance in the same suite also favors AMD heavily: 2,765 versus 1,700, a 62.6% advantage. This pattern continues in Cinebench R15, with the Ryzen 7 3800X leading by 14.9% multi-core (1,974 vs 1,718) and 13.9% single-core (278 vs 244). In Cinebench R20, the margins narrow but remain in AMD’s favor: 5% multi-core (8,226 vs 7,834) and 5.1% single-core (1,161 vs 1,105).

PassMark results reinforce AMD’s dominance in most areas. Data compression shows a 21.1% lead (304,853 vs 251,651), data encryption a 28.7% lead (19,337 vs 15,026), and extended instructions a 33.3% lead (20,037 vs 15,028). Prime number finding favors AMD by 15.7% (103 vs 89), and random string sorting by 13.4% (32,869 vs 28,980). Even in multi-thread performance, AMD edges ahead by 2.8% (23,046 vs 22,422), despite the Intel chip having more cores.

The Intel Core Ultra 5 135H wins 5 benchmarks, and its victories are substantive, not marginal. The biggest win is in PassMark floating point math, where Intel scores 54,867 versus AMD’s 39,759, a 27.5% advantage. PassMark physics also favors Intel by 17.3% (1,482 vs 1,226). In integer math, Intel leads by 7.9% (73,509 vs 67,725). The most notable Intel win is in PassMark single-thread performance, where it scores 3,521 versus AMD’s 2,712, a 23% lead that appears in both the "single_thread" and "singlethread" tests. This indicates Intel has superior per-thread throughput on specific workloads, even as AMD wins most legacy single-core Cinebench tests.

Specification Differences

The two processors differ across nearly every major specification category. The AMD Ryzen 7 3800X has 8 cores and 16 threads, while the Intel Core Ultra 5 135H has 14 cores and 18 threads. Base clocks are close, with AMD at 3.90 GHz and Intel at 3.60 GHz, but boost clocks flip, with Intel at 4.60 GHz and AMD at 4.50 GHz. TDP is a major differentiator: AMD consumes 105 watts versus Intel’s 28 watts.

Cache specifications reveal different design priorities. The Ryzen 7 3800X has 64 KB L1 and 512 KB L2 per core, with 32 MB L3. The Core Ultra 5 135H has 112 KB L1 and 2 MB L2 per core, with 18 MB L3. Memory support differs fundamentally: AMD uses DDR4 with 51.2 GB/s bandwidth, while Intel uses DDR5 with 89.6 GB/s bandwidth (dependent on motherboard). PCIe capabilities also differ: AMD offers Gen 4 with 24 lanes, while Intel offers Gen 5 with 8 lanes. The Intel part includes integrated Arc Xe-LPG 96EU graphics, a feature absent from the AMD desktop chip.

Form factor and platform compatibility are entirely different. The Ryzen 7 3800X uses AMD Socket AM4, is a desktop part, and has an unlocked multiplier. The Core Ultra 5 135H uses Intel BGA 2049, is a mobile part, and has a locked multiplier. Their launch MSRPs are also distinct: the AMD part launched at $399, while the Intel part launched at $342. Both support dual-channel memory and lack ECC support, but their production statuses are both marked as active.

The Verdict

The data supports a clear division of use cases. The AMD Ryzen 7 3800X is the superior choice for legacy multi-threaded workloads and most general-purpose computing. Its 64.9% lead in Cinebench R23 multi-core and 33.3% lead in extended instructions make it the stronger pick for content creation, compilation, and other heavily threaded tasks. The 2.8% advantage in PassMark multi-thread, despite having fewer cores, underscores its efficiency in scaling traditional desktop workloads.

The Intel Core Ultra 5 135H is the better option for specific math-intensive tasks and single-thread responsiveness. Its 27.5% win in floating-point math and 17.3% win in physics suggest strengths in scientific computing and simulation. The 23% lead in PassMark single-thread performance indicates faster per-core execution in certain workloads, which could benefit lightly threaded applications. Its integrated graphics and 28-watt TDP also make it suitable for mobile systems where discrete GPUs are unavailable and power is constrained.

Users seeking maximum multi-core throughput on a desktop platform should select the AMD Ryzen 7 3800X. Users needing a mobile processor with strong floating-point math, physics simulation, and single-thread PassMark performance, along with integrated graphics, should choose the Intel Core Ultra 5 135H. The 12-5 win count for AMD is balanced by Intel’s larger margins in its victories, making the choice highly workload-dependent.