CPU Comparison

The Intel Core i5-2500 and Intel Xeon E5645 are two end-of-life processors from different Intel lineages, yet the benchmark data places them in nearly identical performance territory. The i5-2500, a desktop Sandy Bridge part, achieves an average benchmark score of 1220, while the Xeon E5645, a Westmere-EP server chip, scores 1211. Both sit at the 34th percentile of all CPUs, and their closest rivals are the same chips: the Intel Core i3-7300T and Intel Xeon E5-1607 v3 appear within 0.8% of both. The data tells a story of divergent designs converging on similar outcomes, but the head-to-head results show a clear, consistent winner: the Xeon E5645 wins all five shared benchmarks, with a uniform 16.9% delta in its favor. This is not a case of two chips trading blows; it is a case of one chip dominating every measured workload despite its lower clock speeds. The verdict hinges on understanding why the older, lower-clocked server chip outperforms the newer desktop part, and what that means for specific use cases.

The Verdict

The data is unambiguous: the Intel Xeon E5645 is the faster processor in every shared benchmark, and it wins by the same 16.9% margin across the board. For multi-threaded workloads, the Xeon’s advantage is substantial, it scores 421 in Cinebench R15 multi-core versus the i5-2500’s 350, and 4187 versus 3479 in Cinebench R23 multi-core. Even in single-core tests, where the i5-2500’s higher 3.70 GHz boost clock should theoretically help, the Xeon still wins: 591 versus 491 in Cinebench R23 single-core, and 248 versus 206 in Cinebench R20 single-core. This is a counterintuitive result, as the i5-2500 has a 3.30 GHz base clock and 3.70 GHz boost, compared to the Xeon’s 2.40 GHz base and 2.67 GHz boost. The Xeon’s six cores and twelve threads, against the i5-2500’s four cores and four threads, appear to overcome the clock deficit even in single-threaded tests. The average benchmark scores, however, are nearly identical, 1220 vs 1211, meaning the Xeon’s wins in Cinebench are offset by the i5-2500’s Geekbench results, where the i5-2500 scores 1883 multi-core and 670 single-core, numbers the Xeon does not have in the shared dataset. For a buyer choosing between these two, the Xeon E5645 is the clear pick for any Cinebench-style rendering workload, while the i5-2500’s Geekbench scores suggest it may hold its own in other applications, though the lack of shared Geekbench data for the Xeon leaves this uncertain. The Xeon also offers ECC memory support and triple-channel DDR3, making it the more robust choice for server or workstation use, whereas the i5-2500 includes Intel HD 2000 integrated graphics and a PCIe Gen 3 interface, which are absent on the Xeon.

Architecture Differences

The two chips come from different architectural generations and market segments, which explains their divergent specifications. The i5-2500 is built on Sandy Bridge, a 32 nm process with 1,160 million transistors on a 216 mm² die, while the Xeon E5645 uses Westmere-EP, also a 32 nm process, with 1,170 million transistors on a larger 239 mm² die. The core counts differ fundamentally: the i5-2500 has four cores and four threads, whereas the Xeon E5645 has six cores and twelve threads, thanks to Hyper-Threading. The Xeon’s cache configuration is also more generous, with 12 MB of shared L3 cache versus the i5-2500’s 6 MB, while both share the same per-core L1 and L2 cache sizes of 64 KB and 256 KB. The i5-2500 uses a dual-channel DDR3 memory bus, while the Xeon E5645 uses a triple-channel DDR3 bus, and only the Xeon supports ECC memory. The sockets are incompatible, the i5-2500 fits Intel Socket 1155, the Xeon fits Intel Socket 1366, and the PCIe generations differ, with the i5-2500 offering Gen 3 with 16 lanes (CPU only) and the Xeon limited to Gen 2. The i5-2500 integrates Intel HD 2000 graphics, a feature the Xeon lacks entirely, marking a clear divide between desktop and server design priorities. Both chips have locked multipliers, and neither has a launch MSRP listed in the data, but their release dates differ by about nine months, with the Xeon arriving in March 2010 and the i5-2500 in January 2011.

Where Each One Wins

The Xeon E5645 wins decisively in all Cinebench tests, which are rendering workloads that scale with core count and thread count. Its six cores and twelve threads give it a structural advantage in multi-threaded tasks, and the data shows a consistent 16.9% lead over the i5-2500 across Cinebench R15, R20, and R23, in both single-core and multi-core variants. The Xeon’s larger 12 MB L3 cache and triple-channel memory bus likely contribute to its ability to outperform the i5-2500 even in single-core tests, despite the i5-2500’s higher clock speeds. The i5-2500’s wins are not visible in the head-to-head data, it wins zero of the five shared benchmarks, but its Geekbench scores, which are absent from the head-to-head list, show a different picture. The i5-2500 scores 1883 in Geekbench multi-core and 670 in single-core, and these numbers are part of its benchmark profile, suggesting it may perform well in workloads that reflect Geekbench’s test suite, which includes tasks like encryption, compression, and HTML5 browsing. The i5-2500 also has the advantage of integrated graphics, making it suitable for systems that need a display output without a discrete GPU, while the Xeon requires a separate graphics card. For a desktop user focused on general productivity or light gaming, the i5-2500’s higher boost clock and integrated GPU could be more practical, but for any compute-heavy rendering or server task, the Xeon’s core and thread count make it the superior choice.

FAQ

Q: Which processor is faster in multi-core Cinebench R23?

A: The Intel Xeon E5645 scores 4187 in Cinebench R23 multi-core, while the Intel Core i5-2500 scores 3479, giving the Xeon a 16.9% advantage.

Q: Does the i5-2500 win any of the shared benchmark tests?

A: No. The head-to-head data shows the Xeon E5645 wins all five shared benchmarks, with the i5-2500 recording zero wins.

Q: Why does the Xeon E5645 win single-core tests despite having a lower clock speed?

A: The Xeon E5645 has a 2.40 GHz base clock and 2.67 GHz boost, while the i5-2500 has a 3.30 GHz base and 3.70 GHz boost, yet the Xeon still wins single-core Cinebench R23 with 591 versus 491. The reason likely lies in its 12 MB L3 cache and triple-channel memory architecture, which the data shows as structural differences.

Q: Do the two processors support ECC memory?

A: Only the Xeon E5645 supports ECC memory; the i5-2500 does not.

Q: What are the average benchmark scores for each processor?

A: The i5-2500 has an average benchmark score of 1220, and the Xeon E5645 has an average of 1211, a difference of just 0.7%.

Q: Which processor has integrated graphics?

A: The Intel Core i5-2500 includes Intel HD 2000 integrated graphics, while the Intel Xeon E5645 has no integrated graphics.

Head-to-Head Benchmarks

The head-to-head results present a rare uniformity: the Xeon E5645 beats the i5-2500 by exactly 16.9% in every single shared test. In Cinebench R15 multi-core, the Xeon scores 421 against the i5-2500’s 350, a difference of 71 points. In Cinebench R20 multi-core, the Xeon reaches 1758 versus 1461, and in Cinebench R23 multi-core, it hits 4187 versus 3479. The single-core results are equally lopsided: the Xeon wins Cinebench R20 single-core with 248 versus 206, and Cinebench R23 single-core with 591 versus 491. The consistency of the 16.9% delta across both single-core and multi-core tests is striking, as it suggests the Xeon’s architectural advantages, its 12 MB L3 cache, triple-channel memory, and six-core design, provide a uniform performance uplift regardless of workload type. The i5-2500’s higher clock speeds do not translate into any benchmark win, and its integrated graphics and PCIe Gen 3 support do not appear in the Cinebench results. The average benchmark scores, however, tell a slightly different story: the i5-2500’s 1220 average is actually 0.7% higher than the Xeon’s 1211, driven by its Geekbench scores of 1883 multi-core and 670 single-core, which have no corresponding Xeon data in the head-to-head set. This means the Xeon’s dominance is limited to Cinebench, and the i5-2500 may be competitive or superior in other benchmark suites, though the absence of shared Geekbench results prevents a direct comparison.

Specification Differences

The two processors differ in nearly every major specification. The Xeon E5645 has six cores and twelve threads, versus the i5-2500’s four cores and four threads. The i5-2500 has a base clock of 3.30 GHz and a boost clock of 3.70 GHz, while the Xeon E5645 runs at 2.40 GHz base and 2.67 GHz boost. The Xeon has a lower TDP of 80 watts, compared to the i5-2500’s 95 watts. The sockets are different: the i5-2500 uses Intel Socket 1155, and the Xeon uses Intel Socket 1366. The architectures diverge, with the i5-2500 on Sandy Bridge and the Xeon on Westmere-EP, though both use a 32 nm process. The Xeon has a larger die size of 239 mm² versus 216 mm² and slightly more transistors at 1,170 million versus 1,160 million. L3 cache differs significantly: the Xeon has 12 MB shared, the i5-2500 has 6 MB shared. Memory support differs in channel configuration, with the i5-2500 using dual-channel DDR3 and the Xeon using triple-channel DDR3, and only the Xeon supports ECC memory. The i5-2500 has PCIe Gen 3 with 16 lanes (CPU only), while the Xeon has PCIe Gen 2. Integrated graphics are present only on the i5-2500, in the form of Intel HD 2000, while the Xeon has none. The market segments differ, with the i5-2500 as a Desktop part and the Xeon as a Server/Workstation part. The release dates are about nine months apart, with the Xeon launching in March 2010 and the i5-2500 in January 2011. Both processors are end-of-life, have locked multipliers, and lack a launch MSRP in the data.