AMD Phenom II X6 1075T vs Intel Xeon E5620 Comparison

The Intel Xeon E5620 and AMD Phenom II X6 1075T are two end-of-life processors from 2010, aimed at different market segments yet landing at nearly identical performance levels in modern benchmarks. The Xeon E5620 is a 4-core/8-thread server part built on Intel’s 32 nm Westmere architecture, while the Phenom II X6 1075T is a 6-core/6-thread desktop chip on AMD’s 45 nm K10 (Thuban) design. Despite their different origins—one for workstations, one for consumer desktops—their average benchmark scores are separated by just 5 points (1029 vs 1024), placing both in the 28th percentile of all CPUs. The data reveals a remarkable parity, with the Xeon winning all five head-to-head Cinebench tests by margins of 0.5% to 0.7%. This analysis walks through where each chip wins, their architectural differences, and what the benchmark numbers mean for a buyer choosing between these two legacy parts.

Where Each One Wins

The head-to-head benchmark results are unambiguous: the Intel Xeon E5620 wins all five recorded tests. The margins, however, are razor-thin. In Cinebench R15 multicore, the Xeon scores 301 against the Phenom’s 299, a 0.7% lead. In Cinebench R20 multicore, the Xeon posts 1255 versus 1249, a 0.5% advantage. The single-core tests show the same pattern: R20 single-core gives the Xeon 177 against 176 (0.6% lead), and R23 single-core gives 422 versus 420 (0.5% lead). The largest delta is in R15 multicore at 0.7%, which is still within run-to-run noise for most benchmarks. The Xeon’s wins are consistent but not decisive.

The Phenom II X6 1075T does not win a single recorded benchmark, yet its scores are close enough that the real-world difference is negligible. In multicore workloads, the Phenom’s two extra physical cores (6 versus 4) should theoretically give it an edge, but the Xeon’s hyper-threading (8 threads versus 6) compensates. The Phenom’s higher base clock (3.00 GHz versus 2.40 GHz) and boost clock (3.50 GHz versus 2.67 GHz) do not translate into a measurable advantage in these Cinebench runs. The use-case split, therefore, is not about performance—it is about platform features. The Xeon targets server/workstation duties with ECC memory support and triple-channel DDR3, while the Phenom targets desktop users with dual-channel DDR2/DDR3 support and a lower-cost AM3 socket. If the workload is purely threaded rendering, the two are effectively tied; if the workload requires ECC memory or triple-channel bandwidth, the Xeon is the only choice.

Architecture Differences

The two chips come from different eras and design philosophies. The Intel Xeon E5620 uses the Westmere architecture (Westmere-EP codename), built on a 32 nm process by Intel. It packs 1,170 million transistors on a 239 mm² die. The Phenom II X6 1075T uses the older K10 architecture (Thuban codename), fabricated on a 45 nm process by GlobalFoundries, with 904 million transistors on a larger 346 mm² die. The smaller process node gives Intel a density advantage—more transistors in less space—while AMD’s larger die reflects the older manufacturing technology.

Core and cache configurations differ significantly. The Xeon has 4 cores with 8 threads (hyper-threading), while the Phenom has 6 cores and 6 threads (no SMT). Per-core cache is larger on the Phenom: 128 KB L1 and 512 KB L2 per core, versus 64 KB L1 and 256 KB L2 on the Xeon. However, the Xeon has a much larger shared L3 cache: 12 MB shared, versus 6 MB shared on the Phenom. This 2x L3 advantage helps the Xeon compensate for smaller per-core caches. The Phenom’s total cache (L1+L2+L3) is larger in aggregate, but the Xeon’s L3 is better positioned for shared workloads across threads.

Memory support is another major divider. The Xeon uses triple-channel DDR3, which provides higher theoretical bandwidth than the Phenom’s dual-channel setup. The Phenom supports both DDR2 and DDR3, but its dual-channel memory bus is limited to 21.3 GB/s (the only memory bandwidth figure in the data). The Xeon’s memory bandwidth is not listed, but its triple-channel design implies a wider path. ECC memory is supported by both. The Phenom’s integrated graphics are described as “on certain motherboards (chipset feature),” meaning it relies on the motherboard chipset rather than the CPU itself; the Xeon has no integrated graphics listed. PCIe is Gen 2 for both.

The market segments reinforce the split: the Xeon is a server/workstation part on Intel Socket 1366, while the Phenom is a desktop part on AMD Socket AM3. The TDPs reflect that: 80 W for the Xeon versus 125 W for the Phenom, a 45 W difference despite the Phenom’s higher clock speeds. The Xeon’s lower TDP and smaller die make it more power-efficient per transistor, but the Phenom’s higher clocks give it better raw single-thread frequency.

FAQ

Q: Which CPU has more physical cores?

A: The AMD Phenom II X6 1075T has 6 physical cores, while the Intel Xeon E5620 has 4 physical cores. However, the Xeon features hyper-threading, giving it 8 threads total versus the Phenom’s 6 threads.

Q: How do their multicore benchmark scores compare?

A: In Cinebench R23 multicore, the Xeon scores 2989 against the Phenom’s 2975, a 0.5% difference. In Cinebench R15 multicore, the Xeon leads 301 to 299, a 0.7% margin. The Xeon wins all four multicore tests, but the deltas are under 1%.

Q: What memory types does each CPU support?

A: The Xeon supports DDR3 with a triple-channel memory bus. The Phenom supports both DDR2 and DDR3 with a dual-channel memory bus, and its memory bandwidth is listed at 21.3 GB/s.

Q: Is ECC memory supported on both chips?

A: Yes, both the Intel Xeon E5620 and the AMD Phenom II X6 1075T support ECC memory, according to the data.

Q: Which CPU has a larger process node?

A: The AMD Phenom II X6 1075T uses a 45 nm process, while the Intel Xeon E5620 uses a 32 nm process. The Xeon’s smaller node allows for more transistors (1,170 million versus 904 million) on a smaller die (239 mm² versus 346 mm²).

Q: What is the TDP difference between the two?

A: The Xeon has a TDP of 80 W, while the Phenom has a TDP of 125 W. This 45 W difference makes the Xeon more power-efficient on paper, despite its lower clock speeds.

Specification Differences

| Specification | Intel Xeon E5620 | AMD Phenom II X6 1075T |

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

| Cores | 4 | 6 |

| Threads | 8 | 6 |

| Base clock | 2.40 GHz | 3.00 GHz |

| Boost clock | 2.67 GHz | 3.50 GHz |

| TDP | 80 W | 125 W |

| Socket | Intel Socket 1366 | AMD Socket AM3 |

| Architecture | Westmere | K10 |

| Codename | Westmere-EP | Thuban |

| Process node | 32 nm | 45 nm |

| Foundry | Intel | GlobalFoundries |

| Transistors | 1,170 million | 904 million |

| Die size | 239 mm² | 346 mm² |

| 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) | 6 MB (shared) |

| Memory support | DDR3 | DDR2, DDR3 |

| Memory bus | Triple-channel | Dual-channel |

| Memory bandwidth | Not listed | 21.3 GB/s |

| Integrated graphics | None | On certain motherboards (chipset feature) |

| Market segment | Server/Workstation | Desktop |

| Release date | 2010-03-15 | 2010-09-20 |

| Part number | SLBV4 | HDT75TFBK6DGRHDT75TFBGRBOX |

Head-to-Head Benchmarks

The five recorded Cinebench tests tell a consistent story of near-total parity. Starting with Cinebench R15 multicore, the Xeon scores 301 against the Phenom’s 299, giving the Intel part a 0.7% lead—the largest margin in any test. In Cinebench R20 multicore, the Xeon posts 1255 versus 1249, a 0.5% edge. The R23 multicore test shows 2989 versus 2975, again a 0.5% difference. These multicore results are striking because the Phenom has two additional physical cores; the Xeon’s hyper-threading and larger 12 MB L3 cache appear to neutralize that advantage.

Single-core tests follow the same pattern, but with even smaller deltas. In Cinebench R20 single-core, the Xeon scores 177 against 176, a 0.6% margin. In R23 single-core, the Xeon leads 422 to 420, a 0.5% difference. The Phenom’s higher clock speeds (3.00 GHz base, 3.50 GHz boost) should theoretically favor it in single-threaded tasks, but the Xeon’s newer architecture (32 nm Westmere versus 45 nm K10) and larger L3 cache compensate. The Xeon wins all five benchmarks, but no single win exceeds 0.7%, meaning the two are functionally interchangeable in these workloads.

The average benchmark scores reinforce this: the Xeon has an average score of 1029, while the Phenom sits at 1024, a difference of 5 points (0.5%). Both sit at the 28th percentile of all CPUs, and their nearest rivals are similarly matched—the Xeon’s nearest rival is the AMD Ryzen Embedded V1202B (1027, 0.2% delta), while the Phenom’s nearest rival is the AMD Ryzen 5 PRO 2500U (1024, 0% delta). Neither chip has a meaningful performance advantage over the other in the recorded data.

The Verdict

The data supports a straightforward conclusion: for raw benchmark performance, there is no winner—the Intel Xeon E5620 edges out the AMD Phenom II X6 1075T in every recorded test, but by margins that range from 0.5% to 0.7%, which is within typical measurement variance. The Xeon wins 5 of 5 head-to-head benchmarks, but the Phenom is never more than 2 points behind in any test. A buyer choosing between these two should base the decision on platform requirements, not benchmark scores.

The Xeon is the pick for server or workstation builds where ECC memory and triple-channel DDR3 matter, and where the lower 80 W TDP is an advantage. Its 8 threads and 12 MB L3 cache make it a solid choice for multithreaded server workloads, despite its lower clock speeds. The Phenom, with its 6 cores and higher 3.00 GHz base clock (3.50 GHz boost), is the better fit for a desktop AM3 system, especially if the user already has DDR2 memory or prefers a motherboard with chipset-integrated graphics. Its 125 W TDP is higher, but its higher clocks may benefit older software that scales poorly beyond 4 threads. The 28th percentile ranking for both chips means neither is competitive against modern processors, but for legacy applications, the choice comes down to socket, memory support, and power envelope—not the 0.5% average benchmark difference.