Intel Xeon 676X vs Intel Xeon 678X Comparison

Head-to-Head Benchmarks

The head-to-head comparison between the Intel Xeon 678X and Intel Xeon 676X shows a decisive overall win for the 678X, which takes 13 of 16 benchmark comparisons. The 678X leads across nearly every metric, with the 676X winning only in physics simulation and single-threaded PassMark tests. The most lopsided results appear in PassMark's extended instructions and prime number workloads, where the 678X leads by 34.4% and 36.9% respectively. The 676X does manage a 5.7% advantage in physics and a 6.4% edge in single-thread performance, but those are isolated bright spots.

Cinebench results show a consistent pattern: the 678X wins every Cinebench R15, R20, and R23 test by 8.2% to 8.3%. In Cinebench R15 multicore, the 678X scores 8444 against 7806, and in single-core it records 1192 against 1101. The R20 multicore result is 35185 versus 32527, while R20 single-core lands at 4967 versus 4591. The R23 multicore score reaches 83775 for the 678X, compared to 77447 for the 676X. These are tight, uniform margins, suggesting the advantage comes from the 678X's additional cores rather than from any clock speed or architectural superiority.

PassMark data compression shows a 24.7% win for the 678X, with scores of 1690896 versus 1355807. Data encryption follows at 23.6% (83598 versus 67638), and floating point math shows a 27.7% margin (362070 versus 283570). Integer math is less lopsided at 14.2% (405075 versus 354777), while random string sorting shows an 18.9% gap (164102 versus 137976). The multithread PassMark result mirrors the Cinebench pattern: 98559 versus 91115, an 8.2% difference. Extended instructions deliver the second-largest delta at 34.4% (141431 versus 105231), and find prime numbers produces the largest at 36.9% (1010 versus 738).

The 676X counters with PassMark physics at 8281 versus 7809, a 5.7% advantage, and PassMark single-thread at 4015 versus 3758, a 6.4% edge. These wins are noteworthy because they occur in workloads that depend more on per-core efficiency than raw core count. However, the 676X's single-thread win does not translate to Cinebench single-core results, where the 678X actually leads by 8.3%. This discrepancy suggests the two processors have different performance profiles depending on the specific instruction mix and workload characteristics.

Where Each One Wins

The Intel Xeon 678X is the clear choice for heavily parallel workloads. Its 48 cores and 96 threads give it a substantial advantage in rendering, scientific computing, and data processing tasks. The PassMark multithread score of 98559 versus 91115 confirms this, as does the consistent 8.2% lead across all Cinebench multicore tests. The 678X also dominates in memory-intensive and instruction-heavy workloads: data compression, encryption, extended instructions, and prime number calculations all show gains between 23.6% and 36.9%. For anyone running encoding, compression pipelines, financial simulations, or database workloads that leverage AVX-512-style extended instructions, the 678X delivers measurably higher throughput.

The 676X wins are narrower and more specialized. Its PassMark physics score of 8281 indicates better performance in physics simulation workloads, likely those that benefit from higher per-core clock rates or specific scheduling behavior. The single-thread PassMark score of 4015 versus 3758 shows a 6.4% advantage in lightly threaded applications, which could matter for legacy software or interactive workloads. However, this advantage does not appear in Cinebench single-core tests, where the 678X leads by 8.3%. The data suggests the 676X is preferable only for workloads that closely match its specific strengths, such as certain physics engines or single-threaded PassMark-style integer tasks. For most users, the 678X's broad superiority across 13 benchmarks makes it the more versatile processor.

The average benchmark score tells the same story. The 678X records an average of 193477 across all tests, placing it in the 99th percentile of all CPUs. The 676X averages 158540, which still ranks in the 98th percentile but represents a 22.0% gap between the two parts. In the nearest rivals comparison, the 678X sits within 0.4% of the AMD EPYC 9335 and 0.7% of the Intel Xeon 6741P, while leading the Intel Xeon 6740E by 3.1% and the AMD EPYC 8534P by 4.5%. The 676X trails the AMD EPYC 9355P by 1.1%, the AMD EPYC 7663 by 2.1%, and the AMD EPYC 9375F by 2.4%, while leading the Intel Xeon 6745P by 2.4%. These rankings place both processors in the top tier of available workstation and server parts, but the 678X holds a higher position overall.

The Verdict

Based strictly on recorded benchmark data, the Intel Xeon 678X is the superior processor for the majority of workloads. It wins 13 of 16 head-to-head comparisons, including every Cinebench test and every PassMark test except physics and single-thread. The 678X offers 48 cores and 96 threads, a 192 MB shared L3 cache, and a boost clock of 4.90 GHz. Its 300 W TDP is higher than the 676X's 275 W, but the performance gains in multithreaded and instruction-heavy tasks are substantial. The 678X also carries a larger die footprint at 2x 598 mm², though both processors share the same 5 nm process node and Granite Rapids architecture.

The Intel Xeon 676X should be selected by users who prioritize its two specific strengths: physics simulation and single-threaded PassMark performance. With 32 cores and 64 threads, a 144 MB shared L3 cache, and a base clock of 2.80 GHz, the 676X achieves a 5.7% win in physics and a 6.4% win in single-thread PassMark. Its 275 W TDP is modestly lower, and its launch MSRP is $2499. For workloads that are not heavily parallel and do not rely on extended instruction sets, the 676X offers competitive performance. However, the 678X's 8.2% to 8.3% lead across all Cinebench results and its 14.2% to 36.9% leads across most PassMark tests make it the stronger all-around choice.

Users running render farms, data compression pipelines, encryption services, or scientific simulations should choose the 678X. Its 24.7% advantage in data compression, 23.6% in encryption, and 36.9% in prime number finding represent real throughput gains. Users running physics engines or single-threaded legacy applications may find the 676X acceptable, but they should verify that their specific workload matches its strengths. The data does not support a general recommendation for the 676X over the 678X.

FAQ

Q: Which processor has more cores and threads?

A: The Intel Xeon 678X has 48 cores and 96 threads, while the Intel Xeon 676X has 32 cores and 64 threads. This core count difference drives most of the 678X's multicore performance advantage.

Q: How large is the cache difference between the two?

A: The 678X has a 192 MB shared L3 cache, while the 676X has a 144 MB shared L3 cache. Both have 112 KB of L1 cache per core and 2 MB of L2 cache per core.

Q: Which processor wins in single-threaded performance?

A: The 676X wins PassMark single-thread with a score of 4015 versus 3758, a 6.4% advantage. However, the 678X wins Cinebench R15, R20, and R23 single-core tests by 8.2% to 8.3%, so the answer depends on the specific benchmark.

Q: What is the memory bandwidth of these processors?

A: Both processors support DDR5 memory with an eight-channel bus and deliver 409.6 GB/s of memory bandwidth. They also both support ECC memory.

Q: Are these processors unlocked for overclocking?

A: Yes, both the 678X and 676X have an unlocked multiplier. They share the same Intel Socket 4710 and have a boost clock of 4.90 GHz.

Q: How do these processors compare to their nearest rivals?

A: The 678X averages 193477, within 0.4% of the AMD EPYC 9335 and 0.7% of the Intel Xeon 6741P. The 676X averages 158540, trailing the AMD EPYC 9355P by 1.1% and the AMD EPYC 7663 by 2.1%.

Architecture Differences

Both processors are built on Intel's Granite Rapids architecture, using a 5 nm process node and the same Intel Socket 4710. They share the same die size of 2x 598 mm² and are manufactured by Intel. The generation is listed as Xeon 600 (Granite Rapids-WS) for both, with active production status and a release date of 2026-02-01. The core count difference is the primary architectural distinction: 48 cores for the 678X versus 32 for the 676X. This creates a 96-thread versus 64-thread gap, directly explaining the 8.2% multicore lead in Cinebench and the 8.2% multithread PassMark lead.

The L3 cache also differs substantially. The 678X carries 192 MB of shared L3 cache, while the 676X has 144 MB. Both processors provide 112 KB of L1 cache per core and 2 MB of L2 cache per core. The base clock favors the 676X at 2.80 GHz versus 2.40 GHz for the 678X, but both boost to 4.90 GHz. The TDP differs by 25 W: 300 W for the 678X and 275 W for the 676X. Both support DDR5 memory with an eight-channel bus and 409.6 GB/s bandwidth, plus ECC memory. PCIe connectivity is identical: Gen 5 with 128 lanes (CPU only). Neither processor includes integrated graphics, and both have unlocked multipliers.

The part numbers differ (SA2CX for the 678X, SA2CY for the 676X), and the launch MSRP is $3749 for the 678X versus $2499 for the 676X. The market segment for both is Server/Workstation. Since both share the same architecture, process node, and socket, the performance delta comes down to core count, cache size, and clock behavior. The 676X's higher base clock helps it in single-threaded PassMark, while the 678X's additional cores and larger cache drive its multicore and instruction-heavy wins. The data shows no architectural surprises: the 678X is effectively a higher-core-count variant of the same Granite Rapids design with a larger L3, and the benchmarks reflect that scaling.