Intel Xeon 6740E vs Intel Xeon 678X Comparison

The Intel Xeon 678X and Intel Xeon 6740E are two very different server processors sharing the same socket but diverging sharply in design philosophy. The 678X is a Granite Rapids part built for raw speed and low-latency throughput, while the 6740E is a Sierra Forest part optimized for massive parallel workloads and energy-efficient core density. Benchmark data shows the 678X wins 12 of 16 head-to-head tests, but the 6740E takes decisive victories in specific data-heavy tasks. Here is how the two split their respective territories.

Where Each One Wins

The Intel Xeon 678X is the clear winner in any workload that depends on single-thread performance or high clock speeds. Its 4.90 GHz boost clock versus 3.20 GHz on the 6740E translates directly into a 88.2% advantage in PassMark single-thread scores (3758 vs 1997). This dominance carries over to Cinebench tests across the board: R15, R20, and R23 multicore and singlecore variants all show the 678X ahead by exactly 29.4%. The 678X also wins in extended instruction workloads (141431 vs 78968, a 79.1% lead), prime number finding (1010 vs 526, a 92% lead), and floating-point math (362070 vs 309333, 17% ahead). For physics simulations, the 678X edges out a narrow 2.6% win (7809 vs 7608). If your application is latency-sensitive, runs deep instruction pipelines, or relies on high-frequency scalar performance, the 678X is the pick.

The Intel Xeon 6740E, despite having the same 96 threads as the 678X (96 threads vs 96 threads), wins where massive data throughput and parallel memory operations matter more than clock speed. Its most striking win is data encryption: 137106 vs 83598, a 39% advantage for the 6740E. It also leads in data compression (1786845 vs 1690896, up 5.4%), integer math (457614 vs 405075, up 11.5%), and random string sorting (220684 vs 164102, up 25.6%). These are classic server workloads: compression, encryption, sorting, and integer arithmetic across many threads. The 6740E’s 96 cores (double the 678X’s 48 cores) allow it to grind through bulk operations that scale linearly with core count, even if each individual core is slower.

FAQ

Q: Which CPU has higher single-thread performance?

A: The Intel Xeon 678X is dramatically faster in single-threaded tests. It scores 3758 in PassMark single-thread versus 1997 for the 6740E, a 88.2% advantage. Cinebench R23 singlecore shows 9140 for the 6740E versus a 29.4% higher score for the 678X, consistent with its 4.90 GHz boost clock.

Q: Does the 6740E ever beat the 678X in multicore tests?

A: No. Despite having twice as many cores (96 vs 48), the 6740E loses every Cinebench multicore test. In Cinebench R23 multicore, the 678X scores 83775 while the 6740E scores 64741, a 29.4% deficit for the 6740E. The 6740E’s wins come in specialized PassMark subtests like data encryption and compression, not in general-purpose render or compute benchmarks.

Q: What explains the 6740E’s wins in encryption and compression?

A: The 6740E has 96 physical cores (vs 48 on the 678X) and a larger L2 cache per module (4 MB vs 2 MB per core). In data encryption (137106 vs 83598) and data compression (1786845 vs 1690896), the sheer core count allows parallel processing of independent data blocks. The 678X’s higher clocks cannot compensate when the workload is fully parallel and memory-bound.

Q: Are both CPUs on the same manufacturing process?

A: Yes, both are built on Intel’s 5 nm process node. However, the 678X uses a dual-die design at 2x 598 mm² total die size, while the 6740E is a single 578 mm² die. The 678X also features a much larger L3 cache: 192 MB shared versus 96 MB shared on the 6740E.

Q: Which CPU supports more PCIe lanes?

A: The 678X provides 128 Gen 5 lanes (CPU only), while the 6740E provides 88 Gen 5 lanes. For systems needing many NVMe drives, GPUs, or high-speed network cards, the 678X offers substantially more expansion headroom.

Q: Is the 678X overclockable?

A: Yes, the multiplier is unlocked on the 678X. The 6740E has a locked multiplier. This, combined with the 678X’s higher boost clock, makes it the only one of the two that can be pushed beyond stock frequency.

Head-to-Head Benchmarks

The most lopsided victories belong to the 678X in Cinebench tests. Across R15, R20, and R23, both multicore and singlecore, the delta is a uniform 29.4% in favor of the 678X. For example, Cinebench R23 multicore: 678X scores 83775, 6740E scores 64741. Cinebench R20 multicore: 35185 vs 27191. This consistency suggests a fundamental per-thread efficiency advantage for the Granite Rapids architecture, not just a clock speed difference.

The 678X also dominates in PassMark’s extended instructions test (141431 vs 78968, +79.1%) and prime number finding (1010 vs 526, +92%). These are workloads sensitive to instruction-level parallelism and branch prediction, where the 678X’s higher frequency and larger L3 cache (192 MB vs 96 MB) pay off. Floating-point math also goes to the 678X (362070 vs 309333, +17%), indicating better FPU throughput per core.

The 6740E’s biggest win is data encryption. It scores 137106 compared to 83598 on the 678X, a 39% margin. This is likely due to the 6740E’s 96 cores handling AES operations in parallel, where the 678X’s 48 cores cannot match aggregate throughput despite higher clocks. Random string sorting shows a 25.6% win for the 6740E (220684 vs 164102), and integer math goes to the 6740E by 11.5% (457614 vs 405075). Data compression is closer: the 6740E leads 1786845 vs 1690896, a 5.4% edge.

The only near-tie is PassMark physics, where the 678X wins narrowly at 7809 vs 7608 (2.6%). This suggests that physics simulations benefit slightly from the 678X’s higher clocks, but the 6740E’s extra cores keep it competitive. Overall, the 678X wins 12 of 16 benchmarks, but the 6740E’s four wins are in heavy data-processing categories that are critical in many server environments.

Specification Differences

The core counts are the most obvious split: the 678X has 48 cores and 96 threads, while the 6740E has 96 cores and 96 threads. Both have the same 2.40 GHz base clock, but the boost clocks diverge sharply: 4.90 GHz on the 678X versus 3.20 GHz on the 6740E. Thermal design power differs accordingly: the 678X is rated at 300 W, the 6740E at 250 W.

Memory support is identical: both use DDR5 with an eight-channel memory bus and 409.6 GB/s bandwidth, plus ECC support. PCIe capability differs: the 678X offers 128 Gen 5 lanes, the 6740E offers 88 Gen 5 lanes. The 678X has an unlocked multiplier; the 6740E’s multiplier is locked. Release dates are also distinct: the 678X launched in February 2026, while the 6740E launched in June 2024. The 678X has a launch MSRP of $3749, and the 6740E has a launch MSRP of $5265. Both are active production parts on the Intel Socket 4710.

Architecture Differences

The 678X is built on the Granite Rapids architecture, part of the Xeon 600 (Granite Rapids-WS) generation. The 6740E uses the Sierra Forest architecture, from the Xeon 6 (Sierra Forest-SP) generation. Both are on Intel’s 5 nm process, but the die layout differs: the 678X is a dual-die design totaling 2x 598 mm², while the 6740E is a single 578 mm² die.

Cache hierarchies are notably different. The 678X provides 112 KB of L1 per core, 2 MB of L2 per core, and a massive 192 MB shared L3. The 6740E offers 96 KB of L1 per core, 4 MB of L2 per module, and 96 MB shared L3. The 678X’s larger L3 cache (double the 6740E’s) helps explain its dominance in extended instructions and prime number tests, where working sets can exceed the smaller cache. The 6740E’s per-module L2 design (4 MB) is tailored for its core-dense layout, sacrificing per-core cache for higher core count.

The 6740E’s Sierra Forest architecture is clearly intended for scale-out workloads, prioritizing core count and power efficiency (250 W TDP) over single-thread speed. The 678X’s Granite Rapids design targets scale-up performance, with higher clocks and more cache per core, accepting a higher 300 W TDP. Neither has integrated graphics.

The Verdict

Choose the Intel Xeon 678X if your workloads are dominated by per-thread performance, latency-sensitive computations, or any application that cannot fully utilize 96 threads. The data shows a 29.4% lead in every Cinebench test, a 88.2% lead in single-thread PassMark, and a 79.1% lead in extended instructions. It also offers more PCIe lanes (128 vs 88) and an unlocked multiplier for those who want to push beyond stock settings. The 678X is the better all-around CPU for mixed server/workstation duties, scientific computing, and any task where a few fast cores beat many slow ones.

Choose the Intel Xeon 6740E if your server runs data-heavy, fully parallel workloads such as encryption, compression, sorting, or integer math across many threads. It wins those specific PassMark tests by substantial margins (39% in encryption, 25.6% in sorting, 11.5% in integer math) while consuming 50 W less TDP. Despite having twice the cores, it loses all Cinebench multicore tests, so it is not a general compute champion. But for bulk data processing at scale, the 6740E’s 96 cores deliver the throughput the 678X cannot match. Its higher launch MSRP reflects that core density, but for these specific workloads, the performance is there.