Intel Xeon X5550

The Intel Xeon X5550 is a quad-core server processor based on the Nehalem architecture, codenamed Gainestown. Released on March 29, 2009, it was built on a 45nm process with 731 million transistors on a 263 mm² die. It supports DDR3 memory in a triple-channel configuration with ECC, and includes PCIe Gen 2 connectivity. The processor operates at a base clock of 2.67 GHz and a boost clock of 3.07 GHz, with a TDP of 95W. Its market segment is Server/Workstation, and it is now end-of-life.

Platform and Compatibility

The Xeon X5550 uses Intel Socket 1366, a platform from the Nehalem generation. The memory controller supports DDR3 with a triple-channel bus, and ECC memory is enabled. PCIe Gen 2 is provided for expansion. The processor is part of the Xeon Gainestown family, and its part number is SLBF5. The production status is end-of-life, meaning the platform is no longer manufactured. The L3 cache is 8 MB shared across the four cores, while each core has 64 KB of L1 and 256 KB of L2 cache. The architecture is Nehalem, and the codename is Gainestown. The socket 1366 platform was designed for high-end desktops and entry-level servers, though the data does not specify the full range of compatible processors. The memory bus is triple-channel, which requires matched DDR3 modules for optimal bandwidth. The processor does not have an unlocked multiplier, so frequency adjustments are limited to the base and boost clocks provided.

Single-Thread vs Multi-Thread Behavior

The Xeon X5550 has 4 cores and 8 threads. In Cinebench R20, the single-core score is 152, while the multi-core score is 1083. In Cinebench R23, the single-core score is 364 and the multi-core score is 2580. The Cinebench R15 multi-core score is 259. The multi-core scores are substantially higher than the single-core scores, indicating that the processor scales well with additional threads. This is typical for a server/workstation part that relies on thread-level parallelism. The single-thread performance is modest, which means that applications with limited parallelism will not benefit from the processor's thread count. The large gap between single and multi scores suggests that the processor is optimized for multi-threaded workloads. For example, the R23 multi-core score of 2580 is far above the single-core score of 364. Similarly, the R20 multi-core score of 1083 dwarfs the single-core 152. The processor's thread count of 8 allows it to handle multiple concurrent tasks effectively.

Power and Thermals

The Xeon X5550 has a TDP of 95W. This is a moderate thermal envelope for a quad-core processor. The 45nm process node and 731 million transistors are key factors in this power draw. The die size is 263 mm², which is relatively large, but the 95W TDP suggests that standard cooling solutions for the socket 1366 platform would suffice. The processor does not have an unlocked multiplier, so overclocking is not supported. The base clock of 2.67 GHz and boost clock of 3.07 GHz are within the power budget. The ECC memory support adds to the stability profile but does not directly affect thermals. The server/workstation market segment implies that cooling designs are oriented toward continuous operation, and the 95W TDP is consistent with that expectation.

How It Compares

The nearest rival is the AMD PRO A8-8650B, which has an average benchmark score of 887. This is 0.2% lower than the X5550's average score of 888. The two processors are effectively tied, with the X5550 holding a negligible edge.

The Intel Core i7-940 posts an average score of 886, also 0.2% lower. This is a similar performance level, indicating that the X5550 and i7-940 are closely matched.

The Intel Core i3-9100HL scores 884, which is 0.4% lower. This is a slightly larger gap, but still within a narrow margin.

The Intel Pentium G4560T has an average score of 882, 0.6% lower. This is the largest delta among the listed rivals, yet the X5550 remains ahead by less than a single percentage point.

Benchmark Performance

The Xeon X5550's average benchmark score is 888, which places it at the 23rd percentile among all CPUs in the database. This means it outperforms 23% of the tracked processors, indicating that it is a low-to-mid-range performer in the current landscape. In Cinebench R23, the multi-core score of 2580 and single-core score of 364 show a wide gap. The R20 results are 1083 and 152 respectively. The R15 multi-core score is 259. These numbers indicate that the processor's strength lies in multi-threaded workloads rather than single-thread tasks. Compared to its nearest rivals, the X5550 leads by margins of 0.2% to 0.6% in average score. For instance, the AMD PRO A8-8650B trails by 0.2%, the Intel Core i7-940 by 0.2%, the i3-9100HL by 0.4%, and the Pentium G4560T by 0.6%. These deltas are small, indicating that the X5550 is effectively at parity with its immediate competitors. The single-core scores are particularly low; for example, the R20 single-core score of 152 is far lower than the multi-core score of 1083. This highlights that the processor is not designed for latency-sensitive tasks. The multi-core scores, while not competitive with modern processors, are adequate for moderate rendering or batch processing.

Who Should Consider It

Based on the benchmark data, the Xeon X5550 is suited for multi-threaded workloads that can utilize its 8 threads. The Cinebench multi-core scores of 1083 (R20) and 2580 (R23) suggest that it can handle moderate rendering tasks. However, the single-core scores of 152 (R20) and 364 (R23) are low, making it a poor choice for gaming or other single-threaded applications. The processor's server/workstation market segment and ECC memory support indicate that it was designed for reliability and data integrity, making it suitable for legacy server or workstation builds where stability is more important than raw speed. The 95W TDP and Socket 1366 platform are compatible with motherboards that support this socket. Since the processor is end-of-life, it is primarily relevant for users maintaining existing systems. The 4 cores and 8 threads are adequate for basic office productivity, but the low single-thread performance may cause noticeable delays in responsive applications. For multi-threaded batch processing, the X5550 can still hold its own against the listed rivals, which are all within a 0.6% performance delta.