AMD Athlon X4 845 vs Intel Xeon E5-2603 v3 Comparison

The AMD Athlon X4 845 and the Intel Xeon E5-2603 v3 occupy different corners of the hardware world—one a desktop part built for consumer sockets, the other a server/workstation processor—yet their benchmark results place them in nearly identical performance territory. Both CPUs sit at the 31st percentile against all CPUs tracked, and their respective average benchmark scores are separated by a razor-thin margin: 1106 for the AMD part versus 1103 for the Intel part. The data shows a head-to-head contest where the Athlon X4 845 edges out the Xeon in every single Cinebench test, but the margins are so small that the results are effectively a statistical tie.

Head-to-Head Benchmarks

The head-to-head results are remarkably consistent across all five Cinebench tests, with the AMD Athlon X4 845 winning every round but never by a margin that would matter in real-world use. In Cinebench R15 multi-core, the Athlon scores 324 against the Xeon's 323, a delta of just 0.3%. The R20 multi-core test shows the same pattern: 1350 versus 1346, again a 0.3% advantage for the AMD chip. Single-core performance follows suit, with the Athlon posting 190 versus 189 in R20 single-core (a 0.5% delta) and 453 versus 452 in R23 single-core (a 0.2% delta). The R23 multi-core test rounds out the sweep at 3215 versus 3207, a 0.2% margin.

What is striking here is not that the Athlon wins all five tests—it does, with a 5-0 record in the head-to-head data—but how consistently narrow those wins are. The largest delta across any test is 0.5% in R20 single-core, which is well within normal run-to-run variance for benchmark software. The average benchmark scores tell the same story: the Athlon's 1106 average edges out the Xeon's 1103, but both parts find themselves surrounded by the same peer group in their respective nearest-rival lists. The Athlon's closest rival is the AMD Opteron 3280 at an identical 1106 average score, while the Xeon's closest rival is the Intel Pentium Gold G6605 at 1103. Both CPUs also appear in each other's rival lists, with the Athlon trailing the Xeon's average score by just 0.3% in the Xeon's data, and the Xeon trailing the Athlon's by the same margin in the Athlon's data.

Architecture Differences

The architectural divide between these two processors is substantial, even if the benchmark results are not. The Athlon X4 845 is built on AMD's Excavator architecture, codenamed Carrizo, using a 28 nm process at GlobalFoundries. It packs 3,100 million transistors into a 250 mm² die. The Xeon E5-2603 v3, by contrast, uses Intel's Haswell architecture, codenamed Haswell-EP, on a 22 nm process at Intel. It contains 2,600 million transistors on a larger 356 mm² die. The transistor counts and die sizes reveal different design philosophies: AMD's smaller die with more transistors versus Intel's larger die with fewer, reflecting the different process technologies and architectural approaches.

Core counts favor the Xeon on paper. The Intel part offers 6 cores and 6 threads, while the Athlon provides 4 cores and 4 threads. But the Athlon compensates with much higher clock speeds: a base clock of 3.50 GHz and a boost clock of 3.80 GHz, versus the Xeon's fixed base clock of 1600.00 MHz with no boost capability at all. The Xeon's clock disadvantage is severe—its base clock is less than half the Athlon's base—yet the benchmark results show the two parts landing within a fraction of a percent of each other. This suggests the Xeon's additional cores and larger cache are doing substantial work to offset its clock deficit.

Cache configurations differ sharply. The Athlon has 320 KB of L1 cache and 2 MB of L2 cache, with no L3 cache at all. The Xeon provides 64 KB of L1 per core and 256 KB of L2 per core, but its defining feature is 15 MB of shared L3 cache. Memory support also diverges: the Athlon uses DDR3 with dual-channel memory and a peak bandwidth of 34.1 GB/s, while the Xeon uses DDR4 with quad-channel memory and a peak bandwidth of 51.2 GB/s. The Xeon also supports ECC memory, which the Athlon does not. PCIe connectivity favors the Xeon as well, with 40 CPU lanes at Gen 3 versus the Athlon's 8 lanes at Gen 3. Both parts lack integrated graphics, and both are end-of-life products, with the Athlon released in February 2016 and the Xeon released in September 2014.

FAQ

Q: Which processor has the higher average benchmark score?

A: The AMD Athlon X4 845 has an average benchmark score of 1106, which is 0.3% higher than the Intel Xeon E5-2603 v3's average score of 1103. Both processors sit at the 31st percentile against all CPUs.

Q: How do the core counts and clock speeds compare?

A: The Xeon E5-2603 v3 has 6 cores and 6 threads, while the Athlon X4 845 has 4 cores and 4 threads. However, the Athlon runs at a 3.50 GHz base clock with a 3.80 GHz boost, whereas the Xeon runs at 1600.00 MHz with no boost clock available.

Q: What memory features differentiate the two CPUs?

A: The Athlon X4 845 supports DDR3 memory with dual-channel configuration and a peak bandwidth of 34.1 GB/s, and it does not support ECC. The Xeon E5-2603 v3 supports DDR4 with quad-channel configuration, a peak bandwidth of 51.2 GB/s, and includes ECC memory support.

Q: Does either processor have a locked or unlocked multiplier?

A: The AMD Athlon X4 845 has an unlocked multiplier, while the Intel Xeon E5-2603 v3 does not. This is consistent with the Athlon's desktop positioning versus the Xeon's server/workstation role.

Q: What is the launch MSRP of the Xeon E5-2603 v3?

A: The Intel Xeon E5-2603 v3 had a launch MSRP of $213. No launch MSRP is listed for the AMD Athlon X4 845.

Q: Which processor has more PCIe lanes?

A: The Xeon E5-2603 v3 provides 40 Gen 3 PCIe lanes from the CPU, while the Athlon X4 845 provides 8 Gen 3 lanes from the CPU. This difference reflects the Xeon's workstation/server design intent.

The Verdict

The benchmark data presents a clear picture: these two processors are performance equals in the Cinebench workloads tested, with the Athlon X4 845 holding a 5-0 head-to-head record but never exceeding a 0.5% delta. For users who already have an AMD Socket FM2+ platform or who need an unlocked multiplier for overclocking, the Athlon X4 845 delivers the same multi-core and single-core performance as the Xeon while consuming less power—65 W TDP versus 85 W—and running on a desktop-oriented socket. The Athlon's higher clock speeds and unlocked multiplier make it the more flexible part for consumer workloads where single-threaded responsiveness matters.

The Xeon E5-2603 v3 justifies its existence through platform features rather than raw compute throughput. Its 6 cores, 15 MB of shared L3 cache, quad-channel DDR4 memory, ECC support, and 40 PCIe lanes make it the appropriate choice for anyone building a server or workstation where memory bandwidth, memory reliability, and PCIe expansion are critical. The Xeon's 51.2 GB/s memory bandwidth is 50% higher than the Athlon's 34.1 GB/s, and its 40 PCIe lanes dwarf the Athlon's 8. For workloads that depend on those platform capabilities—virtualization, large datasets, multiple expansion cards—the Xeon is the only viable option despite its clock speed disadvantage.

Specification Differences

| Specification | AMD Athlon X4 845 | Intel Xeon E5-2603 v3 |

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

| Cores | 4 | 6 |

| Threads | 4 | 6 |

| Base Clock | 3.50 GHz | 1600.00 MHz |

| Boost Clock | 3.80 GHz | None |

| TDP | 65 W | 85 W |

| Socket | AMD Socket FM2+ | Intel Socket 2011-3 |

| Architecture | Excavator | Haswell |

| Codename | Carrizo | Haswell-EP |

| Process Node | 28 nm | 22 nm |

| Foundry | GlobalFoundries | Intel |

| Transistors | 3,100 million | 2,600 million |

| Die Size | 250 mm² | 356 mm² |

| L1 Cache | 320 KB | 64 KB (per core) |

| L2 Cache | 2 MB | 256 KB (per core) |

| L3 Cache | None | 15 MB (shared) |

| Memory Support | DDR3 | DDR4 |

| Memory Bus | Dual-channel | Quad-channel |

| Memory Bandwidth | 34.1 GB/s | 51.2 GB/s |

| ECC Memory | No | Yes |

| PCIe Lanes | 8 (Gen 3) | 40 (Gen 3) |

| Market Segment | Desktop | Server/Workstation |

| Release Date | 2016-02-01 | 2014-09-07 |

| Launch MSRP | Not listed | $213 |

| Multiplier | Unlocked | Locked |

| Part Number | AD845XACI43KA | SR20A |