Intel Xeon 6315P vs Intel Xeon 6756E Comparison

Head-to-Head Benchmarks

The benchmark data shows a fascinating split between these two Xeon processors, with the 6315P winning 12 of the 17 recorded comparisons and the 6756E taking 5. The most dramatic gap appears in single-threaded performance, where the 6315P scores 3795 in PassMark single-thread tests against the 6756E's 1646, a 130.6% advantage. This is the largest delta in the entire head-to-head set, and it reflects a fundamental design divergence rather than a minor tuning difference.

The Cinebench suite tells a consistent story across all six tests, with the 6315P winning each by roughly 4.2%. In Cinebench R23 multicore, the 6315P posts 10134 versus 9728 for the 6756E, while in single-core it leads 1430 to 1373. The R20 results mirror this pattern: 4256 versus 4085 in multicore, and 600 versus 576 in single-core. Even in R15, which is an older workload, the margins hold at 1021 versus 980 multicore and 144 versus 138 single-core.

PassMark tests reveal where the 6756E compensates for its single-thread deficit. The most striking win for the 6756E is in data encryption, where it scores 8409 against the 6315P's 5470, a 35% advantage. Integer math also favors the 6756E at 30806 versus 27046, a 12.2% edge. Physics simulation shows the 6756E ahead at 1463 versus 1156, a 21% gap, while random string sorting goes to the 6756E at 15847 versus 14487, an 8.6% advantage. Data compression narrowly favors the 6756E at 123443 versus 118313, a 4.2% margin.

The 6315P dominates several other PassMark metrics. Extended instructions show the 6315P at 10539 versus 6596, a 59.8% lead. Floating point math goes to the 6315P at 33496 versus 22451, a 49.2% margin. Prime number finding favors the 6315P at 150 versus 133, a 12.8% difference, and multithread testing shows the 6315P at 11923 versus 11445, a 4.2% edge.

The average benchmark scores confirm the overall parity. The 6315P averages 14574 with a 69th percentile ranking across all CPUs, while the 6756E averages 14163 with a 68th percentile. Both processors sit near the same performance tier despite radically different configurations. The 6315P's nearest rivals include the AMD EPYC 7473X at an identical average score, the AMD Ryzen 5 5500U at 0.1% below, and the Intel Core i5-9600K at 0.2% below. The 6756E's closest competitors are the Intel Core i5-10400F at 0.2% below, the AMD EPYC 7552 at 0.3% above, the Intel Core 7 160UL at 0.5% below, and the AMD Ryzen 3 7320C at 0.8% below.

Architecture Differences

The two processors come from entirely different design lineages. The 6315P uses Raptor Lake architecture, specifically the Raptor Lake-R variant, and belongs to the Xeon 6 generation labeled as Raptor Lake Refresh. It is built on Intel's 10 nm process with a die size of 163 mm². The 6756E uses Sierra Forest architecture, also a Xeon 6 product but designated Sierra Forest-SP, fabricated on a 5 nm process with a die size of 578 mm².

Core counts diverge dramatically. The 6315P has 4 cores and 4 threads, while the 6756E has 128 cores and 128 threads. Neither processor supports simultaneous multithreading, as both show thread counts equal to core counts. Clock speeds invert the core count relationship: the 6315P runs at 2.80 GHz base and 4.70 GHz boost, whereas the 6756E runs at 1.80 GHz base and 2.60 GHz boost.

Cache hierarchies reflect the different design goals. The 6315P features 80 KB of L1 per core, 1.25 MB of L2 per core, and 12 MB of shared L3. The 6756E offers 96 KB of L1 per core, 4 MB of L2 per module, and 96 MB of shared L3. The much larger L3 on the 6756E suggests a design aimed at keeping many cores fed with data, while the 6315P's per-core L2 allocation supports high-frequency execution.

Memory support differs significantly. The 6315P supports both DDR4 and DDR5 in a dual-channel configuration, while the 6756E supports only DDR5 but across eight channels with a memory bandwidth of 409.6 GB/s. Both support ECC memory, which suits their server and workstation market segment designation. PCIe connectivity also diverges: the 6315P offers Gen 5 with 16 lanes from the CPU, while the 6756E offers Gen 5 with 88 lanes from the CPU.

Sockets separate the platforms completely. The 6315P uses Intel Socket 1700, while the 6756E uses Intel Socket 4710. Neither processor has integrated graphics, and neither has an unlocked multiplier. The 6756E carries a TDP of 225 watts, while the 6315P draws 55 watts, a fourfold difference in power envelope that aligns with the core count disparity.

Where Each One Wins

The data paints a clear picture of workload suitability. The 6315P excels in latency-sensitive, high-frequency tasks where per-core performance matters more than aggregate throughput. Its 4.70 GHz boost clock and 130.6% single-thread advantage make it the obvious choice for lightly threaded applications, interactive workloads, and scenarios where a single core must respond quickly. The extended instructions benchmark, where the 6315P leads by 59.8%, suggests superior SIMD and instruction-level parallelism for computation-heavy single-threaded code. Floating point math, with its 49.2% edge, reinforces this interpretation.

The 6756E shines in throughput-oriented tasks that parallelize well and tolerate lower clock speeds. Its 35% lead in data encryption points to strong cryptographic workload performance, likely benefiting from the sheer number of cores handling independent encryption streams. Integer math, with its 12.2% advantage, indicates that the 128 cores can outpace the 4 high-frequency cores when the work is embarrassingly parallel. Physics simulation, where the 6756E leads by 21%, and random string sorting, with an 8.6% edge, both represent workloads that scale with core count.

The Cinebench results are the notable exception, as the 6315P wins all six tests despite the 6756E having 32 times the cores. This suggests that Cinebench's rendering workload responds strongly to clock speed and per-core cache behavior, or that the 6756E's lower clock limits its scalability in this particular benchmark. The data compression result, where the 6756E wins by only 4.2%, shows that even in a traditionally parallel workload, the margin is modest.

For server deployments, the 6756E's 88 PCIe lanes and eight-channel memory with 409.6 GB/s bandwidth position it for data-heavy environments with many peripherals and high memory throughput demands. The 6315P, with its 16 PCIe lanes and dual-channel memory, suits smaller configurations where board real estate and power consumption are constrained. The 55-watt TDP of the 6315P versus 225 watts for the 6756E means the smaller part can operate in denser chassis with simpler cooling.

FAQ

Q: Which processor has higher single-core performance?

A: The Intel Xeon 6315P wins the single-thread PassMark test with a score of 3795 versus 1646 for the 6756E, a 130.6% advantage. It also leads in Cinebench R23 single-core at 1430 versus 1373.

Q: Does the 128-core Xeon 6756E outperform the 4-core Xeon 6315P in multicore tests?

A: No. The 6315P wins all six Cinebench multicore tests, including R23 multicore at 10134 versus 9728, and the PassMark multithread test at 11923 versus 11445. The 6756E does win in PassMark integer math, physics, data encryption, data compression, and random string sorting.

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

A: The 6756E supports eight-channel DDR5 memory with a bandwidth of 409.6 GB/s. The 6315P supports dual-channel DDR4 and DDR5 memory, and the database does not record a bandwidth figure for it.

Q: How do these processors compare in terms of power consumption?

A: The 6315P has a TDP of 55 watts, while the 6756E has a TDP of 225 watts. The 6756E consumes four times the power envelope of the 6315P.

Q: Which processor has more PCIe lanes?

A: The 6756E offers 88 PCIe Gen 5 lanes from the CPU, while the 6315P offers 16 PCIe Gen 5 lanes from the CPU. The 6756E provides more than five times the lane count.

Q: Are these processors in the same performance percentile?

A: Yes, they are close. The 6315P sits at the 69th percentile of all CPUs with an average benchmark score of 14574, while the 6756E sits at the 68th percentile with an average score of 14163.

Specification Differences

| Specification | Intel Xeon 6315P | Intel Xeon 6756E |

|----------------|------------------|------------------|

| Cores | 4 | 128 |

| Threads | 4 | 128 |

| Base Clock | 2.80 GHz | 1.80 GHz |

| Boost Clock | 4.70 GHz | 2.60 GHz |

| TDP | 55 W | 225 W |

| Socket | Intel Socket 1700 | Intel Socket 4710 |

| Architecture | Raptor Lake | Sierra Forest |

| Codename | Raptor Lake-R | Sierra Forest |

| Generation | Xeon 6 (Raptor Lake Refresh) | Xeon 6 (Sierra Forest-SP) |

| Process Node | 10 nm | 5 nm |

| Die Size | 163 mm² | 578 mm² |

| L1 Cache | 80 KB (per core) | 96 KB (per core) |

| L2 Cache | 1.25 MB (per core) | 4 MB (per module) |

| L3 Cache | 12 MB (shared) | 96 MB (shared) |

| Memory Support | DDR4, DDR5 | DDR5 |

| Memory Bus | Dual-channel | Eight-channel |

| Memory Bandwidth | Not recorded | 409.6 GB/s |

| PCIe | Gen 5, 16 Lanes (CPU only) | Gen 5, 88 Lanes (CPU only) |

| Release Date | 2025-02-23 | 2024-06-02 |

| Part Number | SRPLX | SRPFX |

Both processors share Intel as the manufacturer, ECC memory support, no integrated graphics, a server and workstation market segment, active production status, and locked multipliers. The 6315P launched with an MSRP of $213, while the 6756E launched with an MSRP of $8428. The release dates differ by roughly eight months, with the 6756E arriving first in June 2024 and the 6315P following in February 2025.