CPU Comparison

The benchmark data is remarkably clear: the Intel Xeon X5550 and Intel Core i7-860 are effectively performance twins, with the Xeon holding a razor-thin edge across every single test. Neither CPU is a meaningful winner in raw compute. The decision between them comes down entirely to platform features, memory support, and market segment, not speed.

The Verdict

The data shows a dead heat in compute performance, with the Intel Xeon X5550 taking all five head-to-head benchmark wins by margins of 0.0% to 0.3%. In Cinebench R15 multi-core, both score exactly 259. In Cinebench R20 multi-core, the Xeon scores 1083 against the i7-860’s 1081, a 0.2% lead. In R23 single-core, the Xeon’s 364 edges out the i7-860’s 363, a 0.3% difference. These deltas are within run-to-run noise. The average benchmark scores tell the same story: 888 for the Xeon versus 886 for the i7-860, with a 0.2% gap. Both sit at the 24th percentile of all CPUs, placing them in the same performance tier as the Intel Core i3-6100 (888), Intel Pentium G4560T (887), and AMD PRO A8-8650B (887).

Pick the Xeon X5550 if your priority is a server/workstation platform with ECC memory support and triple-channel DDR3. The Xeon is built for reliability and memory bandwidth, and its socket (Intel Socket 1366) targets multi-socket server boards. Pick the Core i7-860 if you need a desktop platform with a simpler dual-channel memory setup and a lower transistor count. The i7-860’s socket (Intel Socket 1156) is designed for mainstream desktops. For raw compute, choose either, the data shows no practical difference. For platform flexibility, the Xeon’s ECC support and triple-channel memory bus give it a structural advantage that no benchmark score can capture.

FAQ

Q: Which CPU is faster in multi-core workloads?

A: The Intel Xeon X5550 wins all multi-core tests, but by negligible margins. In Cinebench R15 multi-core, both score 259. In R20 multi-core, the Xeon leads 1083 to 1081 (0.2%). In R23 multi-core, the Xeon leads 2580 to 2574 (0.2%). These are effectively ties.

Q: Is the Core i7-860 better for single-threaded tasks?

A: No. The Xeon X5550 wins single-core tests too. In Cinebench R20 single-core, both score 152. In R23 single-core, the Xeon leads 364 to 363 (0.3%). The i7-860 has a higher base clock (2.80 GHz vs 2.67 GHz) and boost clock (3.47 GHz vs 3.07 GHz), but the benchmark results do not reflect a corresponding performance advantage.

Q: Do these CPUs support ECC memory?

A: Yes for the Xeon X5550, which has ECC memory support. No for the Core i7-860, which does not support ECC. This is a critical differentiator for server/workstation use where data integrity is paramount.

Q: What are the memory channel configurations?

A: The Xeon X5550 supports triple-channel DDR3 memory. The Core i7-860 supports dual-channel DDR3 memory. The Xeon’s wider memory bus provides higher theoretical memory bandwidth, though the benchmark data does not include a memory-specific test.

Q: How do these CPUs compare to their nearest rivals?

A: Both CPUs sit at the 24th percentile. The Xeon’s nearest rivals include the Intel Core i3-6100 (888, 0% delta), Intel Pentium G4560T (887, 0.1% delta), and AMD PRO A8-8650B (887, 0.2% delta). The i7-860’s nearest rivals are the same, with the AMD PRO A8-8650B and Pentium G4560T at 887 (-0.1% delta) and the Xeon at 888 (-0.2% delta).

Q: What is the production status of these CPUs?

A: Both are end-of-life. The Xeon X5550 was released on 2009-03-29, and the Core i7-860 was released on 2009-09-07.

Architecture Differences

Both CPUs share the same Nehalem architecture and 45 nm process node, but they come from different codenames and target different segments. The Xeon X5550 is codenamed Gainestown and is a server/workstation part. The Core i7-860 is codenamed Lynnfield and is a desktop part. This difference in codename reflects distinct platform designs.

The transistor count differs: the Xeon X5550 has 731 million transistors on a 263 mm² die, while the Core i7-860 has 774 million transistors on a 296 mm² die. The i7-860 is physically larger and contains more transistors, yet it does not translate into higher benchmark scores. Both have the same cache hierarchy: 64 KB L1 per core, 256 KB L2 per core, and 8 MB shared L3.

The memory architecture diverges significantly. The Xeon X5550 supports triple-channel DDR3 and ECC memory, making it suitable for error-correcting server workloads. The Core i7-860 supports dual-channel DDR3 and does not support ECC, reflecting its desktop orientation. The Xeon’s socket is Intel Socket 1366, while the i7-860 uses Intel Socket 1156. Both support PCIe Gen 2, but the i7-860 specifies 16 lanes (CPU only), while the Xeon does not specify lane count in the data.

The market segment is the clearest architectural split: the Xeon is built for server/workstation reliability, the i7-860 for desktop performance. Neither has integrated graphics, and both have locked multipliers. The Xeon’s part number is SLBF5, while the i7-860’s is SLBJJ. Both are end-of-life, and neither has a launch MSRP listed in the data.

Specification Differences

The core and thread counts are identical: 4 cores and 8 threads for both. The base clock differs: the Xeon X5550 runs at 2.67 GHz, while the Core i7-860 runs at 2.80 GHz. The boost clock gap is larger: 3.07 GHz for the Xeon versus 3.47 GHz for the i7-860. Despite the i7-860’s higher clocks, benchmark scores do not favor it.

The sockets differ: Intel Socket 1366 for the Xeon, Intel Socket 1156 for the i7-860. The memory bus differs: triple-channel for the Xeon, dual-channel for the i7-860. ECC memory support is present on the Xeon and absent on the i7-860. The transistor count and die size differ: 731 million transistors on 263 mm² for the Xeon, versus 774 million on 296 mm² for the i7-860.

The PCIe specification is the same generation (Gen 2), but the i7-860 explicitly lists 16 lanes (CPU only), while the Xeon does not specify. The market segment differs: Server/Workstation for the Xeon, Desktop for the i7-860. The release dates differ: 2009-03-29 for the Xeon, 2009-09-07 for the i7-860. The part numbers differ: SLBF5 for the Xeon, SLBJJ for the i7-860. All other fields, L1/L2/L3 cache, TDP (95 for both), process node (45 nm), foundry (Intel), memory support (DDR3), integrated graphics (none), multiplier lock (locked), production status (end-of-life), and launch MSRP (none), are identical.

Head-to-Head Benchmarks

The data shows a clean sweep for the Intel Xeon X5550, though every win is marginal. In Cinebench R15 multi-core, both CPUs score exactly 259, and the Xeon is declared the winner with a 0% delta. This is a perfect tie, but the head-to-head record credits the Xeon based on the tiebreaker rule.

In Cinebench R20 multi-core, the Xeon scores 1083 against the i7-860’s 1081, a 0.2% lead. In Cinebench R20 single-core, both score 152, another 0% delta in the Xeon’s favor. In Cinebench R23 multi-core, the Xeon scores 2580 against 2574, a 0.2% lead. In Cinebench R23 single-core, the Xeon scores 364 against 363, a 0.3% lead.

The pattern is consistent: the Xeon never loses, but it never wins by more than 0.3%. The i7-860’s higher base clock (2.80 vs 2.67 GHz) and boost clock (3.47 vs 3.07 GHz) do not produce any benchmark advantage. The Xeon’s triple-channel memory bus and ECC support do not appear to boost compute scores either, since the tests are CPU-bound. The average benchmark score reinforces this: 888 for the Xeon versus 886 for the i7-860.

The nearest rival data places both CPUs in the same performance tier. The Xeon’s closest rival is the Intel Core i3-6100 at 888 (0% delta), followed by the Pentium G4560T at 887 (0.1% delta), the AMD PRO A8-8650B at 887 (0.2% delta), and the i7-860 at 886 (0.2% delta). The i7-860’s closest rivals are the AMD PRO A8-8650B and Pentium G4560T at 887 (-0.1% delta each), the Xeon at 888 (-0.2% delta), and the Core i3-6100 at 888 (-0.3% delta). Both CPUs are effectively interchangeable in compute performance.

Where Each One Wins

The Intel Xeon X5550 wins on platform features that matter for server and workstation deployments. It supports ECC memory, which is critical for error-sensitive workloads like databases and scientific computing. Its triple-channel DDR3 memory bus provides higher memory bandwidth than the i7-860’s dual-channel setup, which can benefit memory-intensive tasks. The Xeon’s socket, Intel Socket 1366, is designed for server platforms that may support multiple CPUs. The data shows the Xeon wins all five head-to-head benchmarks, albeit by margins of 0.0% to 0.3%. Its average benchmark score of 888 edges out the i7-860’s 886.

The Intel Core i7-860 wins on desktop practicality. It targets the Desktop market segment with a mainstream Intel Socket 1156 platform. It has a higher base clock (2.80 GHz vs 2.67 GHz) and boost clock (3.47 GHz vs 3.07 GHz), which in theory should favor single-threaded response, though the benchmark data shows no such advantage. It has a larger die (296 mm² vs 263 mm²) and more transistors (774 million vs 731 million), which may indicate a more complex design but does not yield higher scores. The i7-860 does not support ECC memory, which simplifies desktop memory compatibility. Its dual-channel memory bus is sufficient for typical desktop workloads.

For use-case selection, choose the Xeon X5550 for server racks, workstations, virtualization hosts, or any environment where ECC memory and triple-channel bandwidth are non-negotiable. The benchmark data supports this choice with a 0.2% to 0.3% edge in multi-core and single-core tests. Choose the Core i7-860 for a desktop build on Socket 1156, where the platform is simpler and the higher clock speeds may offer intangible responsiveness benefits. The data does not show any compute advantage for the i7-860, but the desktop platform is easier to integrate into consumer systems. Both are end-of-life, so the decision is about fitting the right platform, not chasing performance.