AMD EPYC 9455P vs Intel Xeon 678X Comparison

The benchmark data is unambiguous: the AMD EPYC 9455P is the dominant performer in this head-to-head, winning 12 of 16 tests against the Intel Xeon 678X. The AMD processor’s victories are not marginal; they include a 121.7% lead in PassMark physics and a 49.7% lead in integer math, while the Intel part manages only narrow wins in floating-point math and single-threaded workloads. The average benchmark score for the AMD EPYC 9455P is 217,854, placing it in the 99th percentile of all CPUs, while the Intel Xeon 678X averages 193,477, also in the 99th percentile.

Head-to-Head Benchmarks

The Cinebench suite delivers a consistent and decisive verdict. Across all five Cinebench tests — R15 multicore, R15 singlecore, R20 multicore, R20 singlecore, and R23 multicore — the AMD EPYC 9455P wins by exactly 18.4% each time. The scores tell the story: in Cinebench R23 multicore, AMD posts 99,206 against Intel’s 83,775; in R20 multicore, the gap is 41,666 versus 35,185. Even in singlecore tests, where Intel’s higher boost clock might be expected to help, AMD leads with an R20 singlecore score of 5,882 compared to Intel’s 4,967. This uniform 18.4% margin across the entire Cinebench suite indicates a fundamental per-core performance advantage for the AMD architecture, not a workload-specific quirk.

The PassMark results reveal where each processor excels. AMD’s biggest win is in integer math, scoring 606,239 against Intel’s 405,075 — a 49.7% advantage. Random string sorting also heavily favors AMD, with a 47.9% lead (242,701 versus 164,102). Data encryption shows a 38% gap (115,403 versus 83,598), and data compression adds a 14.1% win (1,928,897 versus 1,690,896). The PassMark multithread score favors AMD by 18.6% (116,927 versus 98,559), and even find prime numbers, a test often sensitive to memory latency, goes to AMD by 9.6% (1,107 versus 1,010).

Intel’s wins are narrow but real. In floating-point math, the Xeon 678X scores 362,070 against AMD’s 357,783, a 1.2% edge. Extended instructions go to Intel by 2.8% (141,431 versus 137,485). The single-thread PassMark test is effectively a tie: Intel scores 3,758 versus AMD’s 3,745, a 0.3% difference. These three wins, plus the duplicate singlethread test, represent the entirety of Intel’s success. The physics test is the most lopsided result: AMD scores 17,315 against Intel’s 7,809, a 121.7% blowout that suggests the AMD chip handles physics simulation workloads with more than double the efficiency.

FAQ

Q: Which processor has the higher average benchmark score?

A: The AMD EPYC 9455P has an average benchmark score of 217,854, which is higher than the Intel Xeon 678X’s 193,477. The AMD part also sits at the 99th percentile of all CPUs, as does the Intel part.

Q: How does the AMD EPYC 9455P compare to its nearest rivals in the database?

A: The AMD EPYC 9455P is 3.8% ahead of the Intel Xeon w9-3595X, 11.8% ahead of the Intel Xeon 6741P, and 12.2% ahead of the AMD EPYC 9335. It trails the Intel Xeon 6747P by 8.6%.

Q: What is the biggest single benchmark margin in this comparison?

A: The largest margin is in PassMark physics, where the AMD EPYC 9455P leads the Intel Xeon 678X by 121.7%, with scores of 17,315 versus 7,809.

Q: Does the Intel Xeon 678X win any benchmark by a significant margin?

A: No. Intel’s largest win is in extended instructions, where it leads by 2.8% (141,431 versus 137,485). Its other wins are 1.2% in floating-point math and 0.3% in single-thread.

Q: Are there any benchmarks where the two processors are nearly identical?

A: Yes. In PassMark single-thread, the Intel Xeon 678X scores 3,758 and the AMD EPYC 9455P scores 3,745, a difference of only 0.3%. Floating-point math is also close, with a 1.2% gap.

Q: How many benchmarks does each processor win overall?

A: The AMD EPYC 9455P wins 12 benchmarks, while the Intel Xeon 678X wins 4 benchmarks (including the duplicate singlethread test).

Architecture Differences

The AMD EPYC 9455P is built on the Zen 5 architecture, codenamed Turin, using a 4 nm process from TSMC. It is part of the EPYC 9005 series. The chip package contains 8 dies, each 70.6 mm², totaling 66,520 million transistors. The Intel Xeon 678X uses the Granite Rapids architecture, also codenamed Granite Rapids, on a 5 nm process from Intel. It belongs to the Xeon 600 generation (Granite Rapids-WS) and uses 2 dies measuring 598 mm² each. The process node difference — 4 nm versus 5 nm — is one factor behind the AMD chip’s higher efficiency in many workloads.

Cache organization differs substantially. The AMD EPYC 9455P provides 80 KB of L1 cache per core, 1 MB of L2 per core, and a shared 256 MB L3 cache. The Intel Xeon 678X counters with 112 KB of L1 per core, 2 MB of L2 per core, but only 192 MB of shared L3. While Intel has larger per-core L1 and L2 caches, AMD’s 256 MB L3 is 33% larger than Intel’s 192 MB, which likely contributes to AMD’s strong performance in data compression and random string sorting.

Memory architecture also diverges. The AMD part supports DDR5 across a twelve-channel memory bus, yielding 576.0 GB/s of bandwidth. The Intel chip also supports DDR5 but over an eight-channel bus, providing 409.6 GB/s. That is a 40.6% bandwidth advantage for AMD, which helps explain its 121.7% lead in physics. Both processors support ECC memory, and both offer PCIe Gen 5 with 128 lanes (CPU only). Neither has integrated graphics. The AMD EPYC 9455P’s boost clock is 4.40 GHz, while the Intel Xeon 678X boosts to 4.90 GHz, yet AMD still wins most tests, underscoring that IPC and memory bandwidth matter more than raw clock speed.

Specification Differences

The core and thread counts are identical: both processors have 48 cores and 96 threads. The base clocks differ, with AMD at 3.15 GHz and Intel at 2.40 GHz; the boost clocks invert this, with Intel at 4.90 GHz and AMD at 4.40 GHz. Both have a TDP of 300 W. The sockets are incompatible: AMD uses Socket SP5, while Intel uses Socket 4710. The AMD part is a 4 nm TSMC design with 66,520 million transistors across 8x 70.6 mm² dies; the Intel part is a 5 nm Intel design with 2x 598 mm² dies. The AMD chip has a 256 MB shared L3 cache, while Intel has 192 MB; AMD offers 80 KB L1 and 1 MB L2 per core, while Intel offers 112 KB L1 and 2 MB L2 per core.

Memory channels favor AMD: twelve channels versus Intel’s eight, with bandwidth of 576.0 GB/s versus 409.6 GB/s. The AMD EPYC 9455P has a locked multiplier, while the Intel Xeon 678X has an unlocked multiplier. The release dates differ significantly — AMD launched on 2024-10-09, while Intel’s launch is listed as 2026-02-01. Both are active production parts and targeted at the server/workstation segment. The AMD part number is 100-000001563, and the Intel part number is SA2CX.

Where Each One Wins

The AMD EPYC 9455P is the clear choice for compute-heavy, parallel workloads. Its 49.7% lead in integer math makes it ideal for database operations, financial modeling, and scientific computing that rely on integer arithmetic. The 121.7% physics advantage points to strong performance in simulation and rendering tasks that use physics engines. The 47.9% lead in random string sorting and 38% lead in data encryption suggest workloads involving large in-memory datasets, logging, or cryptographic processing will run markedly better on the AMD part. The 14.1% compression advantage means file servers or backup systems would benefit from the AMD chip.

The Intel Xeon 678X has a smaller set of use cases. Its 2.8% win in extended instructions indicates a slight edge in workloads that use specialized CPU instruction sets, such as AVX-512-heavy scientific code. The 1.2% floating-point math win makes it marginally better for pure floating-point number crunching. The 0.3% single-thread edge is negligible in practice, but in the rare case where a single-threaded task is the bottleneck, the Intel part is nominally faster. The Intel chip also has an unlocked multiplier, which could appeal to users who plan to overclock, though this is unusual in the server segment.

The Verdict

The data directs a straightforward conclusion: the AMD EPYC 9455P is the superior processor for most workloads. It wins 12 of 16 benchmarks, often by double-digit margins, and its average benchmark score of 217,854 exceeds Intel’s 193,477 by 12.6%. The AMD part’s twelve-channel memory bus and 576.0 GB/s bandwidth give it a structural advantage that shows up in physics, integer math, and random string sorting. Its 256 MB L3 cache and 4 nm process node provide a foundation for the consistent 18.4% Cinebench wins.

The Intel Xeon 678X is not without merit. It wins in floating-point math and extended instructions, making it a reasonable pick for narrowly focused floating-point or instruction-set-specific workloads. Its 4.90 GHz boost clock and unlocked multiplier are also notable, though these do not translate into benchmark victories outside of the single-thread test. For users running mixed server workloads — databases, compression, encryption, multithreaded rendering — the AMD EPYC 9455P wins decisively. For users whose entire workload is floating-point math or extended instruction sets, the Intel part offers a slight edge, but the margin is under 3% in both cases.

Given the 121.7% physics gap and the 49.7% integer math gap, the AMD EPYC 9455P is the safer choice for general-purpose server and workstation deployment. The Intel Xeon 678X should be selected only when its specific strengths — floating-point math, extended instructions, and an unlocked multiplier — are the primary requirements. The data supports AMD as the overall winner, with Intel retaining niche appeal for specialized numerical workloads.