AMD A8-6600K vs Intel Xeon E5520 Comparison

Head-to-Head Benchmarks

The recorded data shows two processors from very different eras and market segments, yet they land in the same performance tier. The AMD A8-6600K carries an average benchmark score of 764, while the Intel Xeon E5520 sits at 742. That is a raw gap of roughly 3% in favor of the AMD part, but the two chips achieve that result through completely different means, and the nearest rival lists confirm how close the overall picture is.

The A8-6600K posts a Geekbench multi-core score of 1076 and a single-core score of 451. The Xeon E5520 has no direct Geekbench entry in the database, but its Cinebench results tell the story. In Cinebench R15 multi-core, the Xeon scores 217. In Cinebench R20, it scores 905 multi-core and 127 single-core. In Cinebench R23, it scores 2155 multi-core and 304 single-core. These are the only cross-referenced numbers available, and they show the Xeon leaning on its eight threads.

The nearest rivals for each chip underline how tightly packed this segment is. The A8-6600K sits 0.3% below the Intel Core i7-3537U, 0.5% above the Core i3-3240, 0.8% above the Core i5-3210M, and 0.9% above the Core i3-5020U. The Xeon E5520 sits 0.1% above the AMD Phenom II X4 B97, 0.2% above the Core i5-670, 0.3% above the Core i7-860S, and 0.3% above the Pentium G4400. Every delta is under a single percentage point, meaning neither chip has a decisive lead over its direct peers. The data indicates that in aggregate throughput, these two are effectively interchangeable.

Where they split is in workload shape. The A8-6600K has four cores and four threads, with a base clock of 3.90 GHz and a boost clock of 4.20 GHz. The Xeon E5520 also has four cores but eight threads, with a base clock of 2.27 GHz and a boost clock of 2.53 GHz. That is a massive clock advantage for the AMD part, nearly 65% higher base frequency, but the Xeon's hyper-threading doubles its logical thread count. In heavily multithreaded Cinebench workloads, the Xeon's thread advantage compensates for its much lower clocks. In single-threaded or lightly threaded tasks, the A8-6600K should pull ahead decisively, given that its 4.20 GHz boost is roughly 66% higher than the Xeon's 2.53 GHz boost. The Cinebench R23 single-core score of 304 for the Xeon gives a baseline, but there is no comparable single-core Cinebench number for the A8, so the direct comparison remains qualitative.

The percentile ranking tells a similar story. Both chips sit at the 20th percentile among all CPUs in the database. That means neither is a standout performer; both are entry-level parts by modern standards. The average benchmark score of 764 for the A8 versus 742 for the Xeon is within noise, and the nearest rival deltas confirm that no competitor in this band has a meaningful edge.

Architecture Differences

The A8-6600K is built on AMD's Piledriver architecture, codenamed Richland, using a 32 nm process from GlobalFoundries. It packs 1,303 million transistors onto a 246 mm² die. The Xeon E5520 uses Intel's Nehalem architecture, codenamed Gainestown, on a 45 nm process from Intel's own fabs. It has 731 million transistors on a 263 mm² die. The transistor count difference is notable: the AMD chip has nearly twice as many transistors, yet the die is smaller, which is a direct consequence of the denser 32 nm node versus the older 45 nm process.

Cache layouts differ sharply. The A8-6600K has 192 KB of L1 cache and 4 MB of L2 cache, with no L3. The Xeon E5520 has 64 KB of L1 per core, 256 KB of L2 per core, and 8 MB of shared L3. For a four-core chip, that works out to roughly 256 KB of L1 total and 1 MB of L2 total for the Xeon, far less than the A8's L2, but the Xeon's 8 MB L3 is a substantial shared resource that the AMD part lacks entirely. This L3 presence matters for server-style workloads with large working sets, while the A8's larger L2 suits desktop-oriented burst tasks.

Memory support also diverges. Both support DDR3, but the A8 uses a dual-channel bus with a recorded bandwidth of 29.9 GB/s. The Xeon uses a triple-channel bus, though its bandwidth figure is not recorded in the database. The Xeon supports ECC memory, while the A8 does not. That is a clear functional separation: the Xeon targets reliability-conscious environments, the A8 targets consumer desktops.

Integrated graphics are another split. The A8-6600K includes a Radeon HD 8570D, making it a complete APU solution. The Xeon E5520 has no integrated graphics, which is expected for a server/workstation part. The A8 also has an unlocked multiplier, allowing easy overclocking, while the Xeon's multiplier is locked.

PCIe generation is identical at Gen 2, but the sockets are incompatible: AMD Socket FM2 for the A8, Intel Socket 1366 for the Xeon. The Xeon's market segment is listed as Server/Workstation, while the A8 is Desktop. Both are end-of-life products, but their release dates differ significantly: the A8 launched in May 2013, the Xeon in March 2009.

The Verdict

From the recorded data, the choice is straightforward. If the workload is primarily single-threaded or lightly threaded, the A8-6600K is the better pick. Its base clock of 3.90 GHz and boost clock of 4.20 GHz dwarf the Xeon's 2.27 GHz base and 2.53 GHz boost. For everyday desktop tasks, legacy software, or gaming that relies on one or two cores, the AMD part will feel snappier.

If the workload is heavily multithreaded and benefits from additional logical threads, the Xeon E5520 is the stronger option. Its eight threads versus the A8's four threads, combined with the 8 MB L3 cache and triple-channel memory bus, make it more suitable for rendering, encoding, virtual machines, or server-style multitasking. The ECC memory support is a decisive factor for anyone running a workstation that requires data integrity.

The average benchmark scores are nearly identical, with the A8 at 764 and the Xeon at 742, and both chips sit at the 20th percentile. Neither is a performance king. The A8 is a desktop APU with integrated graphics and an unlocked multiplier, ideal for a budget build where overclocking is desired and a discrete GPU is not mandatory. The Xeon is a locked server processor without graphics, requiring a discrete GPU and a compatible Socket 1366 motherboard, but offering ECC support and triple-channel memory.

Specification Differences

| Specification | AMD A8-6600K | Intel Xeon E5520 |

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

| Cores | 4 | 4 |

| Threads | 4 | 8 |

| Base Clock | 3.90 GHz | 2.27 GHz |

| Boost Clock | 4.20 GHz | 2.53 GHz |

| TDP | 100 W | 80 W |

| Socket | AMD Socket FM2 | Intel Socket 1366 |

| Architecture | Piledriver | Nehalem |

| Process Node | 32 nm | 45 nm |

| Transistors | 1,303 million | 731 million |

| Die Size | 246 mm² | 263 mm² |

| L1 Cache | 192 KB | 64 KB (per core) |

| L2 Cache | 4 MB | 256 KB (per core) |

| L3 Cache | None | 8 MB (shared) |

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

| Memory Bandwidth | 29.9 GB/s | Not recorded |

| ECC Memory | No | Yes |

| Integrated Graphics | Radeon HD 8570D | None |

| Market Segment | Desktop | Server/Workstation |

| Multiplier Unlocked | Yes | No |

| Release Date | 2013-05-31 | 2009-03-29 |

FAQ

Q: Which processor has more threads?

A: The Intel Xeon E5520 has 8 threads, while the AMD A8-6600K has 4 threads. Both have 4 physical cores.

Q: Does the AMD A8-6600K include integrated graphics?

A: Yes, it includes a Radeon HD 8570D. The Intel Xeon E5520 has no integrated graphics.

Q: Which chip supports ECC memory?

A: Only the Intel Xeon E5520 supports ECC memory. The AMD A8-6600K does not.

Q: What is the clock speed difference between the two?

A: The AMD A8-6600K has a base clock of 3.90 GHz and a boost clock of 4.20 GHz. The Intel Xeon E5520 has a base clock of 2.27 GHz and a boost clock of 2.53 GHz.

Q: Are both processors still in production?

A: No, both are listed as end-of-life products.

Q: Which processor has an unlocked multiplier?

A: The AMD A8-6600K has an unlocked multiplier. The Intel Xeon E5520 does not.

Where Each One Wins

The A8-6600K wins in scenarios that favor high clock speeds and a complete desktop package. Its 4.20 GHz boost clock is a massive advantage for single-threaded responsiveness. The integrated Radeon HD 8570D removes the need for a discrete GPU in basic systems. The unlocked multiplier makes it a candidate for overclocking, which can push performance even higher. Its 4 MB L2 cache and dual-channel memory at 29.9 GB/s are adequate for typical desktop workloads. This is the chip for a media center, a light office PC, or a legacy gaming rig where single-core performance matters more than thread count.

The Xeon E5520 wins in server and workstation environments. Its 8 threads allow it to handle parallel workloads that the A8 cannot. The 8 MB L3 cache provides a large shared pool for data that is reused across cores. The triple-channel memory bus offers higher theoretical memory bandwidth, even though the exact figure is not recorded. ECC memory support is a non-negotiable requirement for many server applications, and the Xeon has it. Its lower TDP of 80 W versus the A8's 100 W also makes it more power-efficient in sustained server loads. This is the chip for a home lab, a virtualization host, or a rendering node where stability and multi-threaded throughput are priorities.

The data shows no clear overall winner. The A8-6600K leads in average benchmark score at 764 versus 742, but that is a 2.9% margin, and the percentile ranking is identical at 20%. The Xeon has no Geekbench entries, and the A8 has no Cinebench entries, so direct cross-benchmark comparison is limited. What the recorded numbers do show is a trade-off: raw clock speed and integrated graphics on the AMD side, thread count and server features on the Intel side. Choose based on the workload, not the brand.