AMD EPYC 7251 vs Intel Core i5-1245U Comparison

Where Each One Wins

The benchmark data is unambiguous: the Intel Core i5-1245U wins every single recorded Cinebench test against the AMD EPYC 7251. Across six head-to-head comparisons, the Intel part takes all six victories. The margins are consistent, with a 2.8% lead in every test, from Cinebench R15 multicore to Cinebench R23 single-core. This is not a case of one chip dominating in one workload and the other in another; the Intel mobile processor simply outperforms the server part across the board in these rendering benchmarks.

The strongest Intel showing comes in Cinebench R23 multicore, where it scores 13053 against the EPYC's 12694. That is a 359-point gap, the largest raw difference in the dataset. The single-core results tell a similar story, with the i5-1245U posting 1842 in R23 single-core versus 1792 for the EPYC 7251. Even in the older R15 tests, where the two chips are closest, the Intel part still leads with 1315 versus 1279 in multicore and 185 versus 180 in single-core.

The EPYC 7251 has no benchmark wins to claim in this comparison. Its average benchmark score is 3671, which places it in the 56th percentile of all CPUs, the same percentile as its Intel rival. The i5-1245U's average score of 3775 is higher, but both chips sit at the same percentile ranking. The data indicates that for anyone choosing between these two purely on Cinebench performance, the Intel i5-1245U is the correct pick.

Architecture Differences

The two processors come from fundamentally different design philosophies and market segments. The Intel Core i5-1245U is a mobile part built on Alder Lake architecture, specifically the Alder Lake-U variant, using Intel's 10 nm process node. It features 10 cores and 12 threads, with a base clock of 1600 MHz and a boost clock of 4400 MHz. The thermal design power is 15 watts, reflecting its ultraportable laptop positioning.

The AMD EPYC 7251 belongs to the EPYC 7001 series, code-named Naples, and uses the Zen architecture on a 14 nm process node from GlobalFoundries. It has 8 cores and 16 threads, with a base clock of 2100 MHz and a boost clock of 2900 MHz. Its thermal design power is 120 watts, a figure that underscores its server and workstation role. The die size is 213 mm² with 4,800 million transistors, details not provided for the Intel part.

Cache configurations differ substantially. The i5-1245U has 80 KB of L1 cache per core, 1.25 MB of L2 per core, and 12 MB of shared L3. The EPYC 7251 has 96 KB of L1 per core, 512 KB of L2 per core, and 32 MB of shared L3. The AMD chip's L3 cache is nearly three times larger, which is typical for a server processor handling data-heavy workloads.

Memory support also separates the two. The Intel part supports both DDR4 and DDR5 in a dual-channel configuration, with no ECC support. The EPYC 7251 supports DDR4 across an eight-channel memory bus with a peak bandwidth of 153.6 GB/s and includes ECC memory support. The Intel chip uses PCIe Gen 4 with 20 lanes from the CPU, while the AMD part uses PCIe Gen 3. The i5-1245U includes integrated Iris Xe graphics with 80 execution units; the EPYC 7251 has no integrated graphics at all.

The sockets are incompatible: Intel BGA 1744 for the i5-1245U versus AMD Socket SP3 for the EPYC 7251. The Intel part is not multiplier-unlocked, while the EPYC 7251 is. Release dates are far apart, with the EPYC launching in June 2017 and the i5-1245U arriving in February 2022.

FAQ

Q: Which processor has higher single-core performance?

A: The Intel Core i5-1245U leads in every single-core test. In Cinebench R23 single-core, it scores 1842 versus 1792 for the EPYC 7251, a 2.8% advantage. The same margin appears in R20 single-core (773 versus 752) and R15 single-core (185 versus 180).

Q: Does the EPYC 7251 win in any Cinebench test?

A: No. The head-to-head data shows the Intel i5-1245U winning all six recorded Cinebench comparisons, including every multicore and single-core test from R15 through R23.

Q: How do the average benchmark scores compare?

A: The i5-1245U has an average benchmark score of 3775, while the EPYC 7251 averages 3671. Both processors sit in the 56th percentile of all CPUs in the database.

Q: What memory configurations do these processors support?

A: The Intel i5-1245U supports DDR4 and DDR5 memory in a dual-channel configuration. The AMD EPYC 7251 supports DDR4 across an eight-channel memory bus with 153.6 GB/s of bandwidth and includes ECC support.

Q: Which processor has more cores and threads?

A: The Intel i5-1245U has 10 cores and 12 threads. The AMD EPYC 7251 has 8 cores and 16 threads. The Intel chip has two more physical cores, but the AMD chip supports four more threads.

Q: What are the power requirements for each chip?

A: The Intel i5-1245U has a thermal design power of 15 watts. The AMD EPYC 7251 has a thermal design power of 120 watts, eight times higher.

Specification Differences

| Specification | Intel Core i5-1245U | AMD EPYC 7251 |

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

| Cores | 10 | 8 |

| Threads | 12 | 16 |

| Base Clock | 1600 MHz | 2100 MHz |

| Boost Clock | 4400 MHz | 2900 MHz |

| TDP | 15 W | 120 W |

| Socket | Intel BGA 1744 | AMD Socket SP3 |

| Architecture | Alder Lake | Zen |

| Codename | Alder Lake-U | Naples |

| Process Node | 10 nm | 14 nm |

| Foundry | Intel | GlobalFoundries |

| Transistors | Not specified | 4,800 million |

| Die Size | Not specified | 213 mm² |

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

| L2 Cache | 1.25 MB per core | 512 KB per core |

| L3 Cache | 12 MB shared | 32 MB shared |

| Memory Support | DDR4, DDR5 | DDR4 |

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

| Memory Bandwidth | Not specified | 153.6 GB/s |

| ECC Memory | No | Yes |

| PCIe | Gen 4, 20 lanes (CPU only) | Gen 3 |

| Integrated Graphics | Iris Xe 80EU | None |

| Market Segment | Mobile | Server/Workstation |

| Multiplier Unlocked | No | Yes |

| Release Date | February 22, 2022 | June 28, 2017 |

Head-to-Head Benchmarks

Every benchmark in the comparison favors the Intel Core i5-1245U, and the margins are identical across all six tests at 2.8%. This uniformity suggests the performance gap is consistent across different Cinebench versions and workload types.

The largest absolute difference appears in Cinebench R23 multicore. The i5-1245U scores 13053, while the EPYC 7251 scores 12694. This 359-point gap represents the most significant single-test difference in the dataset. In Cinebench R20 multicore, the Intel part scores 5482 against 5331 for the AMD chip, a 151-point margin. The R15 multicore test shows 1315 versus 1279, a 36-point gap.

Single-core results follow the same pattern. Cinebench R23 single-core has the i5-1245U at 1842 and the EPYC 7251 at 1792. In R20 single-core, the scores are 773 and 752 respectively. The R15 single-core test shows 185 versus 180. All three single-core tests produce the same 2.8% delta as the multicore tests.

The EPYC 7251's nearest rivals in the database include the AMD Ryzen 7 PRO 1700X with an average score of 3673 (0.1% lower), the Intel Core i3-13100E at 3668 (0.1% higher), the Intel Xeon E5-2658A v3 at 3658 (0.4% higher), and the AMD EPYC 7301 at 3685 (0.4% lower). The i5-1245U's nearest rivals are the AMD Ryzen 7 PRO 2700 at 3777 (0% difference), the Intel Core i7-9700KF at 3787 (0.3% lower), the Intel Core i7-8086K at 3800 (0.6% lower), and the Intel Core i5-11600T at 3742 (0.9% higher).

The context from these rival comparisons is telling. The i5-1245U's average score of 3775 places it just 2 points behind the Ryzen 7 PRO 2700 and 12 points behind the Core i7-9700KF. The EPYC 7251's 3671 average sits 2 points behind the Ryzen 7 PRO 1700X and 14 points behind the EPYC 7301. Both chips are competitive within their respective peer groups, but the Intel part holds a higher absolute average.

The Verdict

The data directs different buyers to different chips, but not for the reasons one might expect from the core counts. The Intel Core i5-1245U is the clear performance winner in Cinebench, taking all six head-to-head tests with a 2.8% margin each time. Its 10 cores, 4.4 GHz boost clock, and 15-watt thermal envelope make it the obvious choice for mobile users who need strong rendering performance in a laptop form factor. The chip supports both DDR4 and DDR5 memory, includes Iris Xe integrated graphics, and uses PCIe Gen 4. Its release in February 2022 makes it a modern option for current mobile designs.

The AMD EPYC 7251 is a server processor with a different set of strengths that the Cinebench scores do not capture. It offers 16 threads from 8 cores, a 32 MB L3 cache, eight-channel DDR4 memory with 153.6 GB/s of bandwidth, and ECC support. These features target memory-intensive server and workstation workloads where data integrity and memory throughput matter more than single-threaded rendering speed. Its 120-watt TDP and Socket SP3 platform place it firmly in rack-mounted or workstation environments, not portable systems.

For a laptop buyer, the i5-1245U is the only practical option. For a server administrator building a system around AMD's Naples platform, the EPYC 7251 brings ECC memory, massive memory bandwidth, and an unlocked multiplier. The benchmark results show the Intel chip outperforming the AMD chip in every recorded Cinebench test, but the EPYC's architectural advantages in memory capacity and error correction serve a different workload class. Both processors sit in the 56th percentile of all CPUs, yet they serve entirely different markets. Choose the i5-1245U for mobile computing with superior Cinebench scores. Choose the EPYC 7251 for server deployments requiring ECC memory and eight-channel bandwidth, accepting its lower rendering performance.