Intel Xeon 638 vs Intel Xeon 6736P Comparison

Head-to-Head Benchmarks

The head-to-head data splits these two Granite Rapids processors into distinct roles. The Intel Xeon 638 wins the majority of the benchmark suite, taking 10 of 17 tests, while the Intel Xeon 6736P secures 7 wins. However, the margin of victory tells a more nuanced story than the raw win count.

The Xeon 638 dominates the Cinebench suite completely. Across all six Cinebench tests, the 638 finishes ahead by a consistent 9.8% margin. This includes Cinebench R23 multicore where the 638 scores 47,202 against the 6736P's 42,561, and Cinebench R23 singlecore where the 638 posts 6,663 versus 6,008. The single-threaded advantage carries into PassMark as well, where the 638's single-thread score of 3,670 crushes the 6736P's 2,024, a staggering 44.9% lead. PassMark multithread also favors the 638, with a score of 55,651 versus 50,072, a 10% advantage.

The 6736P answers back in specialized workloads. Its largest win comes in PassMark random string sorting, where it scores 103,723 against 74,318, a 39.6% advantage. PassMark physics shows a 38.8% lead with 6,531 versus 4,704. Data encryption favors the 6736P by 28.3%, posting 46,236 against 36,030. Integer math goes to the 6736P by 11.9% (206,833 versus 184,884), and data compression shows a 9.8% win (796,658 versus 725,818). Smaller margins appear in floating point math, up 3.5% (149,770 versus 144,757), and find prime numbers, up 2.9% (392 versus 381). The extended instructions test is nearly a tie, with the 638 ahead by just 1.7% (56,498 versus 55,563).

What the data shows is a processor that wins on raw thread throughput and single-core speed, and another that wins on memory-intensive and specialized instruction workloads. The 638's Cinebench sweep is consistent, but the 6736P's wins in encryption, sorting, and physics are often larger in magnitude.

Architecture Differences

Both processors share the Granite Rapids architecture, the 5 nm process node, and the same 598 mm² die size. They also share the same Intel Socket 4710, which means they are physically interchangeable in compatible platforms. The core counts differ substantially: the 6736P packs 36 cores and 72 threads, while the 638 offers 16 cores and 32 threads. This core deficit explains why the 638 still manages to win multithreaded Cinebench tests: it runs at higher clocks.

Clock speeds favor the 638. The 638 has a base clock of 3.20 GHz and a boost clock of 4.80 GHz, while the 6736P runs at 2.00 GHz base and 4.10 GHz boost. The 638's higher boost clock drives its dominant single-thread performance. The 6736P compensates with more than double the cores, which helps in parallel workloads that scale well.

Cache allocation differs as well. Both have 112 KB of L1 per core and 2 MB of L2 per core, but the shared L3 cache is split: the 6736P has 144 MB shared, while the 638 has 72 MB shared. The 6736P's larger L3 cache likely contributes to its wins in data encryption and random string sorting, where larger working sets benefit from more cache.

Memory architecture is another differentiator. The 6736P supports eight-channel DDR5 memory with a bandwidth of 409.6 GB/s. The 638 supports quad-channel DDR5 with 204.8 GB/s. The 6736P's doubled memory bandwidth is a clear advantage for memory-bound workloads, and it shows in the data compression and physics results.

PCIe lanes differ as well. The 6736P offers 88 Gen 5 lanes from the CPU, while the 638 provides 80. Both support ECC memory and have no integrated graphics. The 638 has an unlocked multiplier, while the 6736P does not, which allows overclocking on the 638. The 6736P belongs to the Xeon 6 (Granite Rapids-SP) generation, while the 638 is part of the Xeon 600 (Granite Rapids-WS) generation. The 6736P has a TDP of 205 watts, while the 638 draws 180 watts. The 6736P's launch MSRP is $3351, while the 638's launch MSRP is $899.

FAQ

Q: Which processor has more cores and threads?

A: The Intel Xeon 6736P has 36 cores and 72 threads, while the Intel Xeon 638 has 16 cores and 32 threads. The 6736P provides more than double the core and thread count.

Q: Why does the Intel Xeon 638 win Cinebench multicore tests despite having fewer cores?

A: The 638 has a higher base clock of 3.20 GHz and boost clock of 4.80 GHz, compared to the 6736P's 2.00 GHz base and 4.10 GHz boost. The higher clocks allow the 638 to finish ahead by 9.8% in all Cinebench tests, including multicore.

Q: Which processor offers more memory bandwidth?

A: The Intel Xeon 6736P supports eight-channel DDR5 memory with 409.6 GB/s bandwidth. The Intel Xeon 638 supports quad-channel DDR5 with 204.8 GB/s. The 6736P has exactly double the memory bandwidth.

Q: What is the largest single benchmark gap between the two processors?

A: The largest gap is in PassMark single-thread performance, where the Intel Xeon 638 scores 3,670 versus the 6736P's 2,024, a 44.9% advantage for the 638.

Q: Are both processors on the same socket and process node?

A: Yes, both use Intel Socket 4710 and the 5 nm process node. They also share the same Granite Rapids architecture and the same 598 mm² die size.

Q: Which processor has more L3 cache?

A: The Intel Xeon 6736P has 144 MB of shared L3 cache, while the Intel Xeon 638 has 72 MB. The 6736P has double the L3 cache.

The Verdict

The data points to a clear split by workload type. The Intel Xeon 638 is the better choice for single-threaded and lightly threaded workloads. Its 44.9% lead in PassMark single-thread and consistent 9.8% advantage across every Cinebench test, both single and multicore, make it the stronger general-purpose compute engine. The 638 also wins PassMark multithread by 10%, which is surprising given its core deficit, but the higher clocks carry it through.

The Intel Xeon 6736P is the better choice for memory-heavy and specialized parallel tasks. Its 39.6% win in random string sorting, 38.8% win in physics, and 28.3% win in data encryption show clear strengths where larger caches and memory bandwidth matter. The 6736P's eight-channel memory and 144 MB L3 cache provide the resources for these workloads to excel.

The average benchmark scores reflect this trade-off. The 6736P has an average benchmark score of 87,864, which places it in the 96th percentile of all CPUs. The 638 has an average score of 80,723, placing it in the 95th percentile. The 6736P's nearest rival is the Intel Xeon 6731P with a delta of 0.1%, while the 638's nearest rival is the AMD Ryzen AI Max+ PRO 395 with a delta of 0%.

For users who prioritize raw single-thread speed, clock-driven throughput, and a lower power envelope at 180 watts, the 638 is the data-supported pick. For users who need maximum memory bandwidth, large L3 cache, and superior performance in encryption, sorting, and physics workloads, the 6736P is the clear winner.

Specification Differences

| Specification | Intel Xeon 6736P | Intel Xeon 638 |

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

| Cores | 36 | 16 |

| Threads | 72 | 32 |

| Base Clock | 2.00 GHz | 3.20 GHz |

| Boost Clock | 4.10 GHz | 4.80 GHz |

| TDP | 205 watts | 180 watts |

| Generation | Xeon 6 (Granite Rapids-SP) | Xeon 600 (Granite Rapids-WS) |

| L3 Cache | 144 MB (shared) | 72 MB (shared) |

| Memory Bus | Eight-channel | Quad-channel |

| Memory Bandwidth | 409.6 GB/s | 204.8 GB/s |

| PCIe Lanes | 88 (Gen 5, CPU only) | 80 (Gen 5, CPU only) |

| Multiplier Unlocked | No | Yes |

| Part Number | SRVNW | SA2DN |

| Launch MSRP | $3351 | $899 |

| Release Date | 2025-02-23 | 2026-02-01 |

Where Each One Wins

The Intel Xeon 638 wins in all Cinebench R15, R20, and R23 tests, both singlecore and multicore, with a uniform 9.8% margin. It also wins PassMark multithread by 10%, PassMark single-thread by 44.9%, and PassMark extended instructions by 1.7%. These wins indicate superiority in general compute, rendering, and single-threaded applications.

The Intel Xeon 6736P wins in PassMark data compression by 9.8%, data encryption by 28.3%, find prime numbers by 2.9%, floating point math by 3.5%, integer math by 11.9%, physics by 38.8%, and random string sorting by 39.6%. These wins indicate superiority in encryption, sorting, physics simulation, and memory-bandwidth-intensive workloads.

The use-case split is straightforward. The 638 suits workloads that depend on clock speed and single-thread performance, such as legacy server applications, database queries with low thread counts, and tasks where per-core licensing matters. The 6736P suits scale-out workloads, memory-heavy analytics, encryption-heavy services, and scientific computing that can exploit 36 cores, 144 MB of L3, and 409.6 GB/s of memory bandwidth. The 6736P's launch MSRP is $3351, and the 638's launch MSRP is $899.