AMD EPYC 7643P vs AMD EPYC 7663 Comparison

The AMD EPYC 7663 and AMD EPYC 7643P are both 7 nm Zen 3 parts on the AMD Socket SP3 platform, but the benchmark data reveals a clear performance hierarchy between them. Across the 17 head-to-head tests, the EPYC 7663 secures 15 wins, while the EPYC 7643P takes only 2. The EPYC 7663’s average benchmark score of 161,973 places it 11.8% above the EPYC 7643P’s 144,824, a gap that puts them in different competitive tiers despite their shared architectural foundation. Both chips sit at the 98th percentile of all CPUs, but the data shows the EPYC 7663 is the stronger compute engine.

Head-to-Head Benchmarks

The EPYC 7663 dominates the Cinebench suite with a consistent 6.2% advantage across every iteration. In Cinebench R23 multi-core, the EPYC 7663 scores 69,773 versus 65,710 for the EPYC 7643P, a delta that holds exactly at 6.2%. Single-core results follow the same pattern: 9,850 versus 9,276 in R23 single-core, again 6.2% apart. This uniformity suggests the performance gap is structural rather than workload-dependent, stemming from the core-count difference rather than any clock-speed advantage.

The PassMark suite shows where the EPYC 7663 truly stretches its lead. The largest margin comes in integer math, where the EPYC 7663 posts 468,096 against 390,775, a 19.8% advantage. Floating-point math follows closely at 16.1% (251,535 versus 216,592), and data encryption shows a 16.9% gap (111,725 versus 95,606). Random string sorting favors the EPYC 7663 by 15% (184,367 versus 160,274), while extended instructions run 9.4% ahead (73,719 versus 67,398). Data compression shows a 9.1% edge (1,447,020 versus 1,326,051).

The EPYC 7643P’s only victories come in the two PassMark single-thread tests, where it scores 2,655 versus 2,606, a 1.8% lead. This is a modest reversal, and it does not appear in the Cinebench single-core results, where the EPYC 7663 wins every time. The physics test is nearly a dead heat, with the EPYC 7663 edging ahead by just 0.2% (8,020 versus 8,002). Prime number finding shows a 3.8% gap (676 versus 651), while multi-thread performance lands at 6.2% (82,087 versus 77,307).

Architecture Differences

Both processors share the same foundational architecture: Zen 3 on TSMC’s 7 nm process, with 33,200 million transistors spread across 8x 81 mm² dies. The codename is Milan for both, and they belong to the EPYC 7003 series. The core counts diverge significantly, with the EPYC 7663 packing 56 cores and 112 threads against the EPYC 7643P’s 48 cores and 96 threads. This 8-core difference is the primary driver of the multi-threaded performance gaps.

Clock speeds tell a different story. The EPYC 7643P has a higher base clock at 2.30 GHz versus 2.00 GHz, and a higher boost clock at 3.60 GHz versus 3.50 GHz. These higher frequencies explain the EPYC 7643P’s single-thread PassMark win, though the effect is small. The TDP reflects the core-count disparity: the EPYC 7663 draws 240 W, while the EPYC 7643P is rated at 225 W.

Cache configurations are identical. Both have 64 KB of L1 per core, 512 KB of L2 per core, and a shared 256 MB L3. Memory support is also the same: DDR4 over an eight-channel bus with 204.8 GB/s of bandwidth, plus ECC support. PCIe capability matches at Gen 4 with 128 lanes from the CPU. The process node, foundry, and transistor count are identical, confirming these are the same silicon design binned differently.

Where Each One Wins

The EPYC 7663 is the clear choice for heavily threaded workloads that scale with core count. Its 6.2% advantage across all Cinebench multi-core tests makes it the stronger option for rendering, simulation, and other compute-bound tasks. The 19.8% lead in integer math and 16.1% lead in floating-point math indicate a significant edge in scientific computing and data processing. The 16.9% encryption advantage and 15% random string sorting lead point to stronger performance in security-focused applications and database operations.

The EPYC 7643P’s single-thread PassMark win, while narrow at 1.8%, suggests it has a slight edge in lightly threaded workloads where clock speed matters more than core count. Its higher base and boost clocks make it marginally better suited to latency-sensitive tasks that cannot utilize more than a few cores. However, this advantage does not extend to Cinebench single-core tests, where the EPYC 7663 wins by 6.2%, so the practical benefit is limited.

For workloads that are memory-bandwidth sensitive, the two are effectively tied. Both offer identical 204.8 GB/s bandwidth over eight channels, meaning memory-bound applications will see no difference. The physics test, which often reflects memory and cache behavior, shows only a 0.2% gap, confirming this equivalence.

Specification Differences

The core and thread counts are the most consequential difference: the EPYC 7663 has 56 cores and 112 threads, while the EPYC 7643P has 48 cores and 96 threads. Base clocks differ by 300 MHz (2.00 GHz versus 2.30 GHz), and boost clocks differ by 100 MHz (3.50 GHz versus 3.60 GHz). TDP ratings differ by 15 W, with the EPYC 7663 at 240 W and the EPYC 7643P at 225 W.

The release dates are separated by roughly two and a half years. The EPYC 7663 launched on March 14, 2021, while the EPYC 7643P arrived on September 4, 2023. The launch MSRP for the EPYC 7663 is $6366, and for the EPYC 7643P it is $2722. Part numbers also differ: 100-000000318100-100000318WOF for the EPYC 7663 and 100-000001285 for the EPYC 7643P.

All other specifications are identical. Both use the AMD Socket SP3, have the same cache hierarchy (64 KB L1, 512 KB L2, 256 MB L3), same memory support (DDR4, eight-channel, 204.8 GB/s, ECC), same PCIe configuration (Gen 4, 128 lanes), and same process technology. Neither has integrated graphics, neither has an unlocked multiplier, and both are marked as Active in production.

FAQ

Q: Which processor has more cores, and by how much?

A: The AMD EPYC 7663 has 56 cores and 112 threads, while the AMD EPYC 7643P has 48 cores and 96 threads. The EPYC 7663 has 8 more cores and 16 more threads.

Q: In which benchmark does the EPYC 7643P beat the EPYC 7663?

A: The EPYC 7643P wins the PassMark single-thread test with a score of 2,655 versus 2,606, a 1.8% advantage. This is its only head-to-head victory, appearing in both the passmark_single_thread and passmark_singlethread entries.

Q: What is the largest performance gap between the two processors?

A: The largest gap is in PassMark integer math, where the EPYC 7663 scores 468,096 compared to 390,775 for the EPYC 7643P, a 19.8% difference. Floating-point math and data encryption follow at 16.1% and 16.9%, respectively.

Q: Do the two processors have the same cache configuration?

A: Yes. Both have 64 KB of L1 per core, 512 KB of L2 per core, and a shared 256 MB L3 cache. There is no difference in cache capacity or hierarchy between them.

Q: How do their clock speeds compare?

A: The EPYC 7643P has a higher base clock of 2.30 GHz versus 2.00 GHz on the EPYC 7663. The boost clock is 3.60 GHz on the EPYC 7643P versus 3.50 GHz on the EPYC 7663. The EPYC 7643P’s higher clocks contribute to its single-thread PassMark win.

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

A: The EPYC 7663 has an average benchmark score of 161,973, while the EPYC 7643P averages 144,824. This represents an 11.8% overall advantage for the EPYC 7663, despite both chips ranking at the 98th percentile of all CPUs.