AMD Athlon PRO 300U vs Intel Xeon E5645 Comparison

FAQ

A: How do the two chips compare in the Cinebench results of the AMD of the AMD and the Intel part of the Intel part of the Intel part of the Intel part of the Intel part of the Intel part of the Intel? A:** The Intel Xeon E5645 wins every head-to-head: 20.6% in R15 multi, 20.7% in R20 multi, 21% in R20 single, 20.7% in R23 multi, and 20.9% in R23 single. The Athlon PRO 300U does not win a single recorded benchmark.

Q: Which chip has higher single-core performance?

A: The Xeon E5645 leads in single-core tests. It scores 59 in Cinebench R15 single-core versus the Athlon’s missing R15 single result, 248 versus 205 in R20 single, and 591 versus 489 in R23 single.

Q: What are the core and thread counts?

A: The Xeon E5645 has 6 cores and 12 threads. The Athlon PRO 300U has 2 cores and 4 threads.

Q: Which processor is more power efficient?

A: The Athlon PRO 300U has a TDP of 15 watts, versus 80 watts for the Xeon E5645. The Athlon also uses a smaller process node, 14 nm versus 32 nm.

Q: Do both support ECC memory?

A: No. The Xeon E5645 supports ECC memory, while the Athlon PRO 300U does not.

Q: Which chip has integrated graphics?

A: Only the Athlon PRO 300U includes integrated graphics, specifically Radeon Vega 3. The Xeon E5645 has no integrated graphics listed.

Q: What is the release timeline?

A: The Xeon E5645 was released in March 2010 and is end-of-life. The Athlon PRO 300U was released in April 2019 and is still active.

Architecture Differences

The two processors come from completely different design eras and market intentions. The Intel Xeon E5645 is a server and workstation part built on the Westmere-EP microarchitecture, using a 32 nm process at Intel’s foundry. The AMD Athlon PRO 300U is a mobile processor using the Zen architecture, specifically Raven Ridge 2, fabricated on a 14 nm process at GlobalFoundries.

The Xeon E5645 packs six cores with twelve threads, reflecting its server heritage. The Athlon PRO 300U offers only two cores and four threads, a typical configuration for a low-power mobile chip. That core advantage is central to the Intel part’s multi-threaded lead.

Cache hierarchies differ significantly. The Xeon E5645 provides 64 KB of L1 per core, 256 KB of L2 per core, and a substantial 12 MB of shared L3 cache. The Athlon PRO 300U has a larger L1 per core at 128 KB, a larger L2 per core at 512 KB, but only 4 MB of shared L3. The Xeon’s triple the amount of L3 cache helps in workloads that repeatedly access a large working set.

Memory support also splits the two. The Xeon E5645 uses DDR3 with a triple-channel memory bus, while the Athlon PRO 300U uses DDR4 with a dual-channel bus. The Xeon supports ECC memory, a key feature for error-sensitive server workloads. The Athlon does not support ECC, which makes it unsuitable for many reliability-critical deployments.

The Xeon E5645 is built for Socket 1366, while the Athlon PRO 300U uses the FP5 mobile socket. The Xeon has PCIe Gen 2 support, while the Athlon lists no PCIe specification in the database. Integrated graphics exist only on the Athlon PRO 300U, with its Radeon Vega 3 iGPU, whereas the Xeon has no integrated graphics at all.

Manufacturing details differ as well. The Xeon E5645 has 1,170 million transistors on a 239 mm² die. The Athlon PRO 300U has no transistor count or die size recorded. The Xeon’s transistor count is high for its era, but the newer 14 nm process on the Athlon allows a much lower TDP.

Clock speeds tell a nuanced story. Both chips start at a 2.40 GHz base clock. The Xeon E5645 boosts to 2.67 GHz, while the Athlon PRO 300U boosts to 3.30 GHz. Despite the Athlon’s higher boost clock, the Xeon still wins every single-core benchmark in the database, indicating that its older architecture delivers more instructions per clock in these tests.

The Verdict

The data points to a clear winner for raw compute performance: the Intel Xeon E5645. It wins all five head-to-head benchmark comparisons, with margins between 20.6% and 21%. The Xeon’s six cores and twelve threads give it a decisive multi-threaded advantage, and its single-core scores are also ahead despite a lower boost clock.

However, the verdict is not simply “buy the faster chip.” The Athlon PRO 300U is a mobile processor with a 15 watt TDP, integrated Radeon Vega 3 graphics, and a modern 14 nm process. It is active in production, while the Xeon is end-of-life. For a small form factor laptop or a low-power embedded system, the Athlon is the only practical choice given its socket, power envelope, and graphics output.

For a server or workstation environment where ECC memory is required, the Xeon E5645 is the clear pick. It supports ECC, has triple-channel DDR3, and offers substantially higher multi-core throughput. The Athlon cannot be used in such a role because it lacks ECC support.

The database’s percentile rankings are close: the Xeon sits at the 34th percentile of all CPUs, while the Athlon sits at the 33rd. Their average benchmark scores are 1211 and 1193, respectively. This suggests that in overall CPU capability, the two are near peers, but the distribution of performance is very different. The Xeon wins through core count and cache, while the Athlon compensates with a higher boost clock and modern architecture, yet still falls short in every recorded test.

Specification Differences

| Specification | Intel Xeon E5645 | AMD Athlon PRO 300U |

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

| Cores | 6 | 2 |

| Threads | 12 | 4 |

| Base Clock | 2.40 GHz | 2.40 GHz |

| Boost Clock | 2.67 GHz | 3.30 GHz |

| TDP | 80 W | 15 W |

| Socket | Intel Socket 1366 | AMD Socket FP5 |

| Architecture | Westmere | Zen |

| Codename | Westmere-EP | Raven Ridge 2 |

| Process Node | 32 nm | 14 nm |

| Foundry | Intel | GlobalFoundries |

| Transistors | 1,170 million | Not recorded |

| Die Size | 239 mm² | Not recorded |

| L1 Cache | 64 KB (per core) | 128 KB (per core) |

| L2 Cache | 256 KB (per core) | 512 KB (per core) |

| L3 Cache | 12 MB (shared) | 4 MB (shared) |

| Memory Support | DDR3 | DDR4 |

| Memory Bus | Triple-channel | Dual-channel |

| ECC Memory | Yes | No |

| PCIe | Gen 2 | Not recorded |

| Integrated Graphics | None | Radeon Vega 3 |

| Market Segment | Server/Workstation | Mobile |

| Production Status | End-of-life | Active |

| Release Date | March 2010 | April 2019 |

| Multiplier Unlocked | No | No |

Head-to-Head Benchmarks

The head-to-head results are remarkably consistent. In Cinebench R15 multi-core, the Xeon E5645 scores 421 against the Athlon’s 349, a 20.6% lead. Moving to Cinebench R20 multi-core, the Xeon scores 1758 versus 1456, a 20.7% margin. In R23 multi-core, the Xeon scores 4187 versus 3468, another 20.7% gap.

Single-core tests show the same pattern. In Cinebench R20 single-core, the Xeon scores 248 and the Athlon scores 205, a 21% difference. In R23 single-core, the Xeon scores 591 and the Athlon scores 489, a 20.9% difference. The Xeon also has a recorded R15 single-core score of 59, while the Athlon has no R15 single-core result in the database.

The consistency of the ~20% delta across all tests is striking. It suggests that the Xeon’s advantage is not workload-specific but rather a general throughput lead. Even though the Athlon has a higher boost clock (3.30 GHz versus 2.67 GHz) and a newer architecture (Zen versus Westmere), it cannot overcome the Xeon’s core count and larger L3 cache.

For multi-threaded workloads, the Xeon’s six cores provide 50% more physical cores and 200% more threads than the Athlon. That structural advantage shows up directly in the multi-core scores. For single-threaded workloads, the Xeon’s older but high-performance cores still beat the Athlon’s Zen cores in these specific Cinebench tests, despite the clock speed disadvantage.

The Athlon’s only recorded benchmark without a Xeon counterpart is Cinebench R15 multi-core, where it scores 349. The Xeon’s R15 multi-core score of 421 is 20.6% higher. No other benchmark in the database shows the Athlon winning or even tying.

Where Each One Wins

The Intel Xeon E5645 wins every benchmark category in the database. Its strengths are clear: multi-threaded rendering and compute tasks benefit directly from six cores and twelve threads. The 12 MB shared L3 cache is another asset, particularly for workloads that cycle through large data sets. ECC memory support makes the Xeon suitable for server environments where data integrity is paramount.

The Xeon’s wins are not marginal. A 20.7% lead in R23 multi-core translates to real time savings in rendering or simulation work. Even in single-core tests, where the Athlon’s higher boost clock should help, the Xeon leads by roughly 21%. For any CPU-bound task, the Xeon is the faster processor.

The AMD Athlon PRO 300U wins in areas not covered by the benchmark scores. Its 15 watt TDP makes it suitable for fanless or low-power mobile designs. The integrated Radeon Vega 3 graphics mean a system can run without a discrete GPU, which is impossible with the Xeon. The Athlon’s DDR4 support and modern 14 nm process are also advantages for new system designs.

The Athlon also wins on production status. It is active, meaning it remains available for new designs. The Xeon is end-of-life, so sourcing new units is likely difficult. For a new project, the Athlon is the practical choice despite its lower performance.

In terms of architecture, the Athlon’s Zen cores are more efficient per clock in theory, but the recorded data shows the opposite in practice. The Xeon’s older Westmere architecture still outperforms in these specific Cinebench tests.

Ultimately, the choice depends on the use case. A rack server or workstation that needs ECC and maximum multi-core throughput should use the Xeon E5645. A compact laptop or embedded system that needs low power and integrated graphics should use the Athlon PRO 300U. The benchmark data favors the Xeon, but the system requirements may favor the Athlon.