AMD EPYC 9565 vs AMD EPYC 9634 Comparison

The AMD EPYC 9634 and AMD EPYC 9565 are two server processors aimed at the same socket and market segment, but they represent very different design philosophies. The 9634 is a high-core-count Zen 4 part built for throughput, while the 9565 is a lower-core-count Zen 5 part built for raw speed per thread. Benchmark results show a clear split: the 9565 wins 15 of 17 head-to-head tests, often by large margins, while the 9634 takes only 2 wins, both in narrow specialty workloads. The average benchmark score tells the story: the 9565 scores 285471, which is 14.4% higher than the 9634’s 244274. Both sit in the 99th percentile of all CPUs, meaning neither is a weak performer, but the data consistently favors the newer architecture.

The Verdict

The AMD EPYC 9565 is the default choice for most buyers. It beats the 9634 in every Cinebench test, both multi-core and single-core, with a consistent 20.2% lead across R15, R20, and R23. In PassMark’s multi-thread test, the 9565 scores 135221 versus 107944, a 20.2% advantage. The 9565 also wins heavily in floating-point math (549422 vs 353784, a 35.6% lead) and extended instructions (209595 vs 137543, a 34.4% lead). For any workload that relies on per-core performance, such as databases, virtualized environments, or real-time analytics, the 9565 is the superior part.

The 9634 is only worth picking for two specific scenarios. First, if you need the absolute highest core count in this comparison, the 9634 has 84 cores versus the 9565’s 72, and it wins PassMark’s data encryption test (151943 vs 141936, a 7.1% lead) and integer math (725356 vs 717948, a 1% lead). These are narrow margins, but for encryption-heavy workloads like VPN gateways or secure data storage, that 7.1% edge could matter. Second, if your software is heavily threaded and scales poorly with clock speed, the 9634’s extra 12 cores might compensate for its slower per-core performance, though the benchmark data does not support this—the 9565 still wins the multi-thread tests decisively. The 9634 also has a lower TDP (290W vs 400W), which could be a factor in dense server deployments where power and cooling are constrained, but the performance penalty is substantial.

Architecture Differences

The two chips come from different generations and process nodes. The 9634 is built on Zen 4 architecture with the codename Genoa, while the 9565 uses Zen 5 with the codename Turin. The 9634 uses a 5 nm process, while the 9565 uses a 4 nm process, both from TSMC. The die size differs slightly: the 9634 uses 12x 72 mm² dies, while the 9565 uses 12x 70.6 mm² dies. Transistor counts are not directly comparable in the fact pack, but the process shrink is a key differentiator.

Core and cache layouts differ in important ways. The 9634 has 84 cores and 168 threads, while the 9565 has 72 cores and 144 threads. The L1 cache is larger on the 9565 at 80 KB per core versus 64 KB per core on the 9634. Both have 1 MB of L2 per core and 384 MB of shared L3 cache. The larger L1 on the 9565 likely contributes to its single-thread performance advantage.

Clock speeds are a major differentiator. The 9634 has a base clock of 2.25 GHz and a boost clock of 3.70 GHz. The 9565 has a base clock of 3.15 GHz and a boost clock of 4.30 GHz. That is a 0.9 GHz higher base and a 0.6 GHz higher boost. This explains why the 9565 wins so decisively in single-core tests, despite having fewer cores.

Memory bandwidth also favors the 9565. Both support DDR5 with a twelve-channel memory bus, but the 9565 delivers 576.0 GB/s versus 460.8 GB/s on the 9634. This 25% bandwidth advantage is significant for memory-bound workloads. Both support ECC memory and have the same PCIe Gen 5 with 128 lanes (CPU only). Both use AMD Socket SP5 and have no integrated graphics. Neither has an unlocked multiplier, so overclocking is not an option for either.

Where Each One Wins

The 9565 dominates in every general-purpose compute category. Its single-thread performance is 20.9% higher in PassMark’s single-thread test (3696 vs 2924). This carries over to all Cinebench single-core tests, where it leads by 20.2% consistently. In multi-threaded workloads, the 9565 still wins despite having 12 fewer cores. The PassMark multi-thread score is 135221 for the 9565 versus 107944 for the 9634, a 20.2% gap. The physics test shows a 31.9% lead for the 9565 (18036 vs 12291), indicating stronger per-core compute. Floating-point math is a 35.6% win for the 9565, and extended instructions (like AVX-512 workloads) are 34.4% faster. Prime number finding is 51.4% faster on the 9565 (2422 vs 1176), which is a massive gap that reflects the clock speed and IPC improvements. Even data compression, a typical multi-threaded server task, favors the 9565 by 13.3% (2579631 vs 2236412).

The 9634 wins in two narrow areas. Data encryption shows a 7.1% lead (151943 vs 141936), which is modest but consistent. Integer math is nearly tied, with the 9634 ahead by just 1% (725356 vs 717948). These wins suggest the 9634’s extra cores provide a slight edge in workloads that are integer-heavy and scale almost perfectly with core count, but the margin is too small to justify choosing it over the 9565 for most applications.

The 9634 also has a lower TDP of 290W versus 400W on the 9565. In a power-constrained environment, this could be the deciding factor, but you pay for that efficiency with significantly lower performance across nearly every benchmark.

FAQ

Q: Which CPU has more cores?

A: The AMD EPYC 9634 has 84 cores and 168 threads, while the AMD EPYC 9565 has 72 cores and 144 threads.

Q: Which CPU is faster in single-threaded performance?

A: The AMD EPYC 9565 is faster, with a PassMark single-thread score of 3696 versus 2924 for the 9634, a 20.9% lead. It also wins all three Cinebench single-core tests by 20.2%.

Q: Does the 9634 win any benchmark?

A: Yes, the 9634 wins PassMark data encryption (151943 vs 141936, a 7.1% lead) and PassMark integer math (725356 vs 717948, a 1% lead). It wins 2 of 17 head-to-head tests.

Q: What is the difference in memory bandwidth?

A: The 9565 has a memory bandwidth of 576.0 GB/s, while the 9634 has 460.8 GB/s. Both use DDR5 with a twelve-channel memory bus.

Q: Are these CPUs compatible with the same motherboard?

A: Yes, both use AMD Socket SP5 and have the same PCIe Gen 5 with 128 lanes (CPU only), so they share platform compatibility.

Q: Which CPU has a higher boost clock?

A: The 9565 has a boost clock of 4.30 GHz, while the 9634 has a boost clock of 3.70 GHz. The 9565 also has a higher base clock at 3.15 GHz versus 2.25 GHz.

Head-to-Head Benchmarks

The Cinebench results are the most striking. In Cinebench R23 multi-core, the 9565 scores 114937 against the 9634’s 91752, a 20.2% advantage. This is remarkable because the 9634 has 12 more cores. In R23 single-core, the 9565 scores 16226 versus 12953, again a 20.2% gap. The same 20.2% delta appears across R15 and R20, both multi-core and single-core. This consistency suggests the 9565’s per-core performance advantage fully offsets its core deficit in multi-threaded workloads.

The PassMark suite shows where the 9565 really pulls ahead. The largest single win is in find prime numbers, where the 9565 scores 2422 versus 1176, a 51.4% lead. This is a synthetic test that heavily rewards clock speed and IPC. Floating-point math shows a 35.6% lead (549422 vs 353784), and extended instructions (which include AVX-512) show a 34.4% lead (209595 vs 137543). Physics is 31.9% faster on the 9565 (18036 vs 12291). These are not marginal differences—they represent a generational leap in compute efficiency.

The 9565 also wins in memory-related tasks. Data compression scores 2579631 versus 2236412, a 13.3% lead, likely benefiting from the higher memory bandwidth. Random string sorting is 10.6% faster (291941 vs 261134). Even the multi-thread test, which should favor the 9634’s core count, goes to the 9565 by 20.2% (135221 vs 107944).

The 9634’s two wins are worth examining closely. In data encryption, it scores 151943 versus 141936. This 7.1% lead is the only benchmark where the 9565 loses by more than a rounding error. In integer math, the 9634 scores 725356 versus 717948, a 1% lead that is nearly a tie. These results indicate that the 9634’s extra cores provide a slight advantage in purely integer, non-floating-point workloads, but the effect is small.

Specification Differences

The two processors differ in nearly every key specification. The 9634 has 84 cores and 168 threads, while the 9565 has 72 cores and 144 threads. The 9634 has a base clock of 2.25 GHz and a boost clock of 3.70 GHz, while the 9565 has a base clock of 3.15 GHz and a boost clock of 4.30 GHz. The 9634 has a TDP of 290W, while the 9565 has a TDP of 400W.

Architecture and process differ: the 9634 uses Zen 4 (Genoa) on a 5 nm process, while the 9565 uses Zen 5 (Turin) on a 4 nm process. Die size is 12x 72 mm² for the 9634 and 12x 70.6 mm² for the 9565. L1 cache is 64 KB per core on the 9634 and 80 KB per core on the 9565. Both have 1 MB L2 per core and 384 MB shared L3. Memory bandwidth is 460.8 GB/s on the 9634 and 576.0 GB/s on the 9565.

Release dates differ: the 9634 launched on 2022-11-09, while the 9565 launched on 2024-10-09. The launch MSRP is $10304 for the 9634 and $10486 for the 9565. Both support DDR5, ECC memory, twelve-channel memory buses, and PCIe Gen 5 with 128 lanes. Both use AMD Socket SP5, have no integrated graphics, and are not multiplier-unlocked. Their part numbers are 100-100000797 for the 9634 and 100-000001447 for the 9565. Both are classified as server/workstation parts and are currently in active production.