AMD EPYC 7643P vs Intel Xeon 6745P Comparison

Intel Xeon 6745P and AMD EPYC 7643P are both high-core-count server processors, but the benchmark data shows they are not interchangeable. The Intel part wins 12 of 16 head-to-head tests, while the AMD part takes 4, and the nature of those wins reveals a clear division of labor. The Xeon 6745P is the superior choice for single-threaded responsiveness, floating-point workloads, and anything that scales across many threads, while the EPYC 7643P holds the edge in integer-heavy, memory-latency-sensitive tasks and physics simulation.

Where Each One Wins

The Intel Xeon 6745P dominates the Cinebench suite and the broader Passmark multi-threaded test. In Cinebench R15, R20, and R23 multi-core, it leads by 8.9% in every case, scoring 7214, 30062, and 71578 respectively against the EPYC's 6623, 27598, and 65710. The Passmark multithread score follows the same pattern: 84210 vs 77307, an 8.9% advantage. This is not a marginal win; it is consistent across three generations of the Cinebench renderer.

The single-core story is even more lopsided. The Xeon 6745P scores 3450 in Passmark single-thread, a full 29.9% ahead of the EPYC's 2655. Cinebench R15 and R20 single-core show a 9% lead for Intel. The Xeon's 4.30 GHz boost clock versus 3.60 GHz on the EPYC is the obvious driver, but the architectural advantage in instructions per clock also shows in the extended instructions test, where Intel wins by 60.7% (108326 vs 67398).

The AMD EPYC 7643P wins where its higher core count and Zen 3 design pay off. It has 48 cores versus 32, and that shows up in integer math: 390775 vs 336926, a 13.8% win for AMD. Passmark physics is another clear AMD win at 8002 vs 6144, a 23.2% advantage, and random string sorting goes to AMD by 16.7% (160274 vs 133528). The most striking AMD win is data encryption, where it scores 95606 against Intel's 66665, a 30.3% margin. These are not rendering workloads; they are compute patterns that reward raw core count and memory bandwidth in a specific way.

The Verdict

For a database server, scientific computing node, or any workload that runs many parallel threads with heavy floating-point math, the Intel Xeon 6745P is the better buy. The data shows it wins every multi-core render test and the floating-point math benchmark by 23.5%. It also has a massive single-thread advantage, which matters for latency-sensitive queries and legacy software that does not scale well.

The AMD EPYC 7643P is the pick when the workload is integer-bound, heavily encrypted, or involves physics simulation. Its 30.3% lead in data encryption and 23.2% lead in physics are too large to ignore. If your application does a lot of sorting, the 16.7% win in random string sorting also favors AMD. The EPYC also has 48 cores over Intel's 32, which gives it more raw parallelism even if the per-core performance is lower.

The overall average benchmark score favors Intel: 154858 vs 144824. That is a 6.9% gap in the aggregate. Both chips sit at the 98th percentile of all CPUs, so either one is a top-tier part. The decision comes down to workload, not overall capability. Choose Intel for general high-performance compute, choose AMD for encryption-heavy and integer-heavy pipelines.

Head-to-Head Benchmarks

The biggest Intel win is in extended instructions, where it scores 108326 against 67398, a 60.7% margin. This is not a niche test; it reflects how well the CPU handles SIMD and vectorized code, which is common in scientific and media workloads. The single-thread Passmark score is the second-largest Intel win at 29.9% (3450 vs 2655), showing a massive per-core advantage.

Floating-point math goes to Intel by 23.5% (267438 vs 216592). This is critical for rendering, simulation, and any number-crunching that uses FPU-heavy code. The Cinebench multi-core tests are all 8.9% Intel wins, which is consistent but not overwhelming. The Intel lead in data compression is modest at 2% (1352801 vs 1326051), and find prime numbers is a 4.6% Intel win (681 vs 651).

The AMD wins are equally instructive. Data encryption is the largest at 30.3% (95606 vs 66665). This is likely due to the EPYC's 48 cores and the Zen 3 architecture's strong cryptographic instruction throughput. Physics is a 23.2% AMD win (8002 vs 6144), which is interesting because physics simulation often benefits from both CPU cache and core count. Random string sorting is a 16.7% AMD win (160274 vs 133528), indicating better memory subsystem efficiency for that access pattern. Integer math is a 13.8% AMD win (390775 vs 336926), the smallest of the four AMD victories.

FAQ

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

A: The Intel Xeon 6745P is significantly faster. It scores 3450 in Passmark single-thread versus 2655 for the AMD EPYC 7643P, a 29.9% advantage. Cinebench R15 and R20 single-core tests also show a 9% lead for Intel.

Q: Does the AMD EPYC 7643P ever outperform the Intel Xeon 6745P?

A: Yes, in four specific tests. The AMD EPYC 7643P wins data encryption by 30.3%, physics by 23.2%, random string sorting by 16.7%, and integer math by 13.8%.

Q: Which CPU has better multi-threaded rendering performance?

A: The Intel Xeon 6745P. It wins Cinebench R15, R20, and R23 multi-core tests by 8.9% each, scoring 7214, 30062, and 71578 respectively. The Passmark multithread score also favors Intel at 84210 vs 77307.

Q: How does the core count difference affect the benchmark results?

A: The AMD EPYC 7643P has 48 cores compared to the Intel's 32, but the Intel wins most multi-threaded tests anyway. The AMD's extra cores help it win integer math and physics, but the Intel's higher per-core performance overcomes the core deficit in most other areas.

Q: What is the memory bandwidth difference between the two?

A: The Intel Xeon 6745P supports DDR5 with a memory bandwidth of 409.6 GB/s, while the AMD EPYC 7643P uses DDR4 with 204.8 GB/s. Both have eight-channel memory buses.

Q: Which CPU has a higher launch MSRP?

A: The Intel Xeon 6745P has a launch MSRP of $5250, while the AMD EPYC 7643P has a launch MSRP of $2722.

Architecture Differences

The Intel Xeon 6745P is built on Granite Rapids architecture using a 5 nm process from Intel, with a die size of 2x 598 mm². The AMD EPYC 7643P uses Zen 3 (Milan) architecture on a 7 nm process from TSMC, with eight dies of 81 mm² each and 33,200 million transistors. The process node difference is meaningful: 5 nm versus 7 nm gives Intel a density and power efficiency advantage.

Cache layouts differ substantially. The Intel part has 112 KB of L1 cache per core, 2 MB of L2 per core, and a massive 336 MB of shared L3 cache. The AMD part has 64 KB L1 per core, 512 KB L2 per core, and 256 MB of shared L3. Intel's larger L3 cache helps explain its wins in floating-point math and extended instructions, where more data can be held on-die.

Memory architecture is a major split. Intel uses DDR5 with 409.6 GB/s bandwidth, while AMD uses DDR4 with 204.8 GB/s. That is a 200 GB/s difference in theoretical bandwidth, which directly contributes to Intel's multi-threaded wins. PCIe support also differs: Intel offers Gen 5 with 88 lanes, while AMD offers Gen 4 with 128 lanes. The AMD part has more lanes, but the Intel part has a faster generation.

The socket and platform are entirely different. Intel uses Socket 4710, AMD uses Socket SP3. This means no drop-in upgrade path between the two, so the platform choice locks you into one vendor's roadmap.

Specification Differences

The core and thread counts differ: Intel has 32 cores and 64 threads, AMD has 48 cores and 96 threads. Clock speeds favor Intel: 3.10 GHz base and 4.30 GHz boost versus 2.30 GHz base and 3.60 GHz boost for AMD. The TDP is lower on the AMD part at 225 watts versus 300 watts for Intel, which is notable for power-constrained racks.

Memory support is a clear split: DDR5 for Intel, DDR4 for AMD. The memory bandwidth reflects this at 409.6 GB/s versus 204.8 GB/s. PCIe generation also differs: Gen 5 for Intel, Gen 4 for AMD, though AMD has more lanes at 128 versus 88.

Cache sizes differ in every level. Intel has 112 KB L1 per core, 2 MB L2 per core, and 336 MB L3. AMD has 64 KB L1 per core, 512 KB L2 per core, and 256 MB L3. The Intel L3 is 80 MB larger, which is a significant advantage for workloads with large working sets.

The process node and foundry are different: Intel uses its own 5 nm process, AMD uses TSMC's 7 nm. The release dates are also different, with Intel launching on February 23, 2025, and AMD on September 4, 2023. Both are active production parts with ECC memory support. The Intel part number is SRWPAQ7L9, the AMD part number is 100-000001285. Neither has unlocked multipliers. The Intel has no integrated graphics, and the AMD part also lacks integrated graphics.