AMD EPYC 8434P vs Intel Xeon 678X Comparison

Head-to-Head Benchmarks

The recorded data leaves little ambiguity about which processor holds the overall performance crown. The Intel Xeon 678X wins 15 of the 16 head-to-head benchmark comparisons, with the only exception being a PassMark data encryption test. The margins are often substantial, sometimes approaching threefold advantages.

Starting with the Cinebench suite, the Intel part is consistently 48% ahead. In Cinebench R15 multi-core, the Xeon 678X scores 8444 against the EPYC 8434P's 5696. The single-core R15 result is nearly identical in percentage terms: 1192 versus 804, a 48.3% lead. Moving to Cinebench R20, the multi-core score is 35185 for Intel versus 23736 for AMD, again a 48.2% gap. Single-core R20 shows 4967 versus 3350, a 48.3% delta. The pattern holds through Cinebench R23, where the Xeon scores 83775 and the EPYC scores 56516, a 48.2% difference. These are not marginal wins; they represent a full generational step in rendering throughput.

The PassMark multi-thread test tells the same story. Intel's 98559 score beats AMD's 66490 by 48.2%. The physics workload is even more lopsided: 7809 versus 4036, a 93.5% advantage for Intel. Prime number finding shows the largest disparity of any test: 1010 versus 298, a 238.9% lead. Floating point math also favors Intel heavily, with 362070 against 215669, a 67.9% margin. Extended instruction performance, a proxy for AVX-class workloads, shows Intel at 141431 versus AMD's 86189, a 64.1% gap.

Integer math is the closest multi-core contest. Intel scores 405075, AMD scores 385290, and the delta shrinks to just 5.1%. Random string sorting favors Intel by a more comfortable 30.3% (164102 versus 125932). Data compression shows Intel ahead at 1690896 versus 1412835, a 19.7% win.

The single-thread PassMark results mirror the Cinebench single-core data. Intel posts 3758, AMD posts 2448, and the delta is 53.5%. That is a decisive advantage for any workload that cannot parallelize across all 96 threads.

The sole AMD victory comes in PassMark data encryption. Here the EPYC 8434P scores 97254 against Intel's 83598, a 14% margin in favor of AMD. This is a notable outlier, suggesting that AMD's cryptographic instruction path is more efficient per clock in this specific test. Every other benchmark in the head-to-head set lands in Intel's column.

Architecture Differences

Both processors are built on a 5 nm process node, but the foundries differ. Intel fabricates the Xeon 678X in-house, while AMD uses TSMC for the EPYC 8434P. The Xeon 678X belongs to the Granite Rapids family, specifically the Xeon 600 generation. Its die is composed of two 598 mm² chips, for a total silicon area of roughly 1196 mm². The EPYC 8434P, codenamed Siena, uses the Zen 4c architecture and is built from four 73 mm² dies, totaling about 292 mm². AMD lists 35,500 million transistors for its part; the database records no transistor count for Intel's chip.

Core counts are identical: 48 cores and 96 threads on both. Clock speeds diverge sharply. The Intel part has a 2.40 GHz base clock and a 4.90 GHz boost clock. The AMD part has a 2.50 GHz base clock but only a 3.10 GHz boost. That 1.80 GHz boost advantage for Intel is the single largest architectural differentiator, and it explains most of the benchmark deltas.

Cache hierarchies also differ. Intel allocates 112 KB of L1 per core, 2 MB of L2 per core, and 192 MB of shared L3. AMD allocates 64 KB of L1 per core, 1 MB of L2 per core, and 128 MB of shared L3. Intel's larger per-core caches and bigger L3 pool give it more headroom for cache-sensitive workloads.

Memory support is another split. Both use DDR5, but Intel runs an eight-channel memory bus with 409.6 GB/s of bandwidth. AMD runs a six-channel bus with 230.4 GB/s. Intel's memory bandwidth is nearly double AMD's, which matters for data-heavy server tasks. Both support ECC memory.

PCIe lanes favor Intel as well: Gen 5 with 128 lanes (CPU only) versus Gen 5 with 96 lanes for AMD. The sockets are incompatible: Intel Socket 4710 versus AMD Socket SP6. The EPYC 8434P has a 200 W TDP, while the Xeon 678X has a 300 W TDP. The Intel part also has an unlocked multiplier, while AMD's is locked. Intel's launch MSRP is $3749; AMD's is $2700.

The release dates are far apart. The EPYC 8434P launched in September 2023, while the Xeon 678X is dated February 2026. Both are listed as Active in production status.

Where Each One Wins

Intel's Xeon 678X is the clear choice for compute-bound parallel workloads. The Cinebench scores across R15, R20, and R23 all show a 48% advantage, which translates directly to faster 3D rendering, simulation, and video encoding. The floating point math result, 67.9% ahead, strengthens the case for scientific and engineering applications. Data compression, which benefits from high memory bandwidth and large caches, also favors Intel by 19.7%.

The single-thread story is entirely Intel's. A 53.5% lead in PassMark single-thread and 48.3% in Cinebench R15 single-core mean that lightly threaded applications, legacy software, and interactive workloads will feel markedly snappier on the Xeon 678X. The physics test, at 93.5% ahead, points to strong per-core integer and branch performance.

AMD's EPYC 8434P has one clear niche: encryption. The 14% lead in PassMark data encryption suggests that cryptographic workloads, such as TLS termination, VPN gateways, or full-disk encryption, will run faster on the Siena part. The lower 200 W TDP also makes it the more power-conscious option for dense server deployments, though the database does not record wattage measurements for comparison.

For memory bandwidth-bound tasks, Intel's 409.6 GB/s versus AMD's 230.4 GB/s is a decisive factor. Any workload that streams large datasets, such as in-memory analytics or database scans, should favor the Xeon 678X. The extra PCIe lanes (128 versus 96) also give Intel more room for high-speed storage arrays or multiple accelerators.

FAQ

Q: Which processor has higher multi-threaded performance?

A: The Intel Xeon 678X. In Cinebench R23 multi-core, it scores 83775 versus the AMD EPYC 8434P's 56516, a 48.2% advantage. The PassMark multi-thread test shows the same pattern: 98559 versus 66490, also a 48.2% lead.

Q: Is the AMD EPYC 8434P faster in any benchmark?

A: Yes, in PassMark data encryption. The EPYC scores 97254 against Intel's 83598, a 14% margin. All other 15 head-to-head benchmarks are won by the Intel Xeon 678X.

Q: How do the clock speeds differ?

A: The Intel Xeon 678X has a 2.40 GHz base clock and a 4.90 GHz boost clock. The AMD EPYC 8434P has a 2.50 GHz base clock and a 3.10 GHz boost clock. Intel's boost clock is 1.80 GHz higher.

Q: What memory bandwidth does each processor support?

A: The Intel Xeon 678X supports eight-channel DDR5 with 409.6 GB/s of bandwidth. The AMD EPYC 8434P supports six-channel DDR5 with 230.4 GB/s. Intel's bandwidth is nearly double.

Q: Do both processors have the same core count?

A: Yes, both have 48 cores and 96 threads. However, Intel's cache configuration is larger: 192 MB of shared L3 versus AMD's 128 MB, and Intel has 2 MB of L2 per core versus AMD's 1 MB.

Q: Which processor has higher single-thread performance?

A: The Intel Xeon 678X. In PassMark single-thread, it scores 3758 versus AMD's 2448, a 53.5% lead. Cinebench R20 single-core shows 4967 versus 3350, a 48.3% advantage.

The Verdict

The benchmark data is unambiguous. The Intel Xeon 678X is the faster processor in nearly every recorded test, and often by very wide margins. For users who prioritize raw compute throughput, multi-threaded rendering, floating point math, or single-thread responsiveness, the Xeon 678X is the correct choice. Its 48% lead across all Cinebench versions and 53.5% single-thread advantage make it the stronger all-around performer.

The AMD EPYC 8434P does have a legitimate use case. Its encryption performance is 14% better than Intel's, which matters for security-focused workloads. Its lower TDP of 200 W versus Intel's 300 W may also be relevant for power-constrained data centers, though the database does not record efficiency per watt. Its earlier release date and lower launch MSRP are also recorded facts.

However, for any mixed or general-purpose server workload, the data points squarely to Intel. The Xeon 678X wins 15 of 16 head-to-head tests, and its wins are not narrow. They range from 5.1% in integer math to 238.9% in prime number finding. The only sensible conclusion is that the Xeon 678X is the higher-performance part, and the EPYC 8434P should be selected only when its encryption advantage or lower power envelope is the deciding factor.