CPU Comparison

The Verdict

The benchmark data delivers an unusually close contest between the Intel Xeon W3520 and the Intel Core i5-2500T, with the Xeon winning all five head-to-head Cinebench tests by margins ranging from 0.6% to 0.8%. The average benchmark scores tell the same story: the Xeon W3520 posts 862 against the i5-2500T’s 856, a gap of roughly 0.7%. Both processors sit at the 23rd percentile among all CPUs, placing them in identical performance tiers. The practical takeaway: the Xeon W3520 is the marginally faster chip in raw compute, but the i5-2500T delivers that nearly identical performance from a 45W TDP versus the Xeon’s 130W, a 65% reduction in thermal design power for a 0.7% performance loss. Users building a system where power efficiency dominates should pick the i5-2500T; users who already own a Socket 1366 workstation platform and need ECC memory support should pick the Xeon W3520. The Xeon’s eight threads versus the i5’s four threads do not translate into meaningful Cinebench advantages, which suggests the older Nehalem architecture’s simultaneous multithreading is largely offset by Sandy Bridge’s superior per-core efficiency.

FAQ

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

A: The Intel Xeon W3520 wins with a score of 2505 against the i5-2500T’s 2489, a delta of 0.6%. This is the smallest margin in the entire head-to-head set, indicating that the two processors are effectively tied in heavily threaded workloads.

Q: Does the i5-2500T’s lack of Hyper-Threading hurt it in single-core tests?

A: No. In Cinebench R20 single-core, the Xeon W3520 scores 148 against the i5-2500T’s 147, and in R23 single-core the Xeon leads 353 to 351. The i5-2500T actually has a higher boost clock (3.30 GHz versus 2.93 GHz), yet still trails by 0.6-0.7%, implying the Xeon’s architecture extracts more work per clock in this workload.

Q: Can the i5-2500T use ECC memory?

A: No. The i5-2500T does not support ECC memory, while the Xeon W3520 explicitly supports ECC. This is a decisive differentiator for workstation or server builds where data integrity is critical.

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

A: The Xeon W3520’s average score of 862 is 0.1% behind the Intel Core i5-3470T (863) and 0.5% ahead of the Intel Xeon X3460 (866). The i5-2500T’s average of 856 is 0.1% behind the Core i5-5250U (856) and 0.5% ahead of the Intel Xeon X5492 (852). Both chips sit in a dense cluster of CPUs scoring between 852 and 866.

Q: Which CPU has more transistors?

A: The i5-2500T has 1,160 million transistors on a 216 mm² die, while the Xeon W3520 has 731 million transistors on a 263 mm² die. The i5-2500T crams nearly 60% more transistors into a smaller area, explaining its dramatically lower 45W TDP.

Q: Is the Xeon W3520’s triple-channel memory support a real advantage?

A: The data does not include memory bandwidth benchmarks, so no quantitative claim can be made. However, the Xeon W3520 supports triple-channel DDR3 while the i5-2500T is limited to dual-channel, which could matter in bandwidth-sensitive workloads not captured by the Cinebench suite.

Architecture Differences

The Xeon W3520 is built on Nehalem architecture with the Bloomfield codename, fabricated on Intel’s 45 nm process node. It packs 731 million transistors across a 263 mm² die. The i5-2500T uses Sandy Bridge architecture, also by Intel, on a 32 nm process with 1,160 million transistors squeezed into a 216 mm² die. The node shrink from 45 nm to 32 nm allowed Intel to nearly double transistor count while reducing die size by 18%, which directly explains the i5-2500T’s 45W TDP versus the Xeon’s 130W.

Cache configurations differ notably. Both chips have 64 KB L1 and 256 KB L2 per core, but the Xeon W3520 offers 8 MB of shared L3 cache while the i5-2500T provides 6 MB. The Xeon’s larger L3 likely compensates for its older architecture, though the benchmark data shows the two achieving nearly identical results.

The Xeon W3520 supports ECC memory and uses a triple-channel DDR3 memory bus, while the i5-2500T lacks ECC support and runs dual-channel DDR3. PCIe generations also differ: the Xeon offers Gen 2, while the i5-2500T provides Gen 3 with 16 lanes (CPU only). The i5-2500T includes Intel HD 2000 integrated graphics; the Xeon has no integrated graphics at all. The Xeon targets server and workstation segments; the i5-2500T targets desktop. Both are end-of-life products, with the Xeon released on 2009-03-29 and the i5-2500T on 2011-01-08.

Threading is a core difference: the Xeon W3520 runs 4 cores with 8 threads via Hyper-Threading, while the i5-2500T runs 4 cores with 4 threads and no Hyper-Threading. Despite this, the Xeon’s multi-core Cinebench scores are only 0.6-0.8% higher, suggesting that Sandy Bridge’s architectural improvements in instruction handling and memory access largely neutralize the Xeon’s threading advantage.

Specification Differences

The most dramatic difference is thermal design power: the Xeon W3520 draws 130W, while the i5-2500T draws just 45W, a 65% reduction. Base clocks differ, with the Xeon at 2.67 GHz and the i5-2500T at 2.30 GHz, but the boost clocks reverse this: the Xeon boosts to 2.93 GHz while the i5-2500T boosts to 3.30 GHz, giving the Sandy Bridge part a 0.37 GHz advantage at peak frequency.

Sockets are incompatible: the Xeon uses Intel Socket 1366, the i5-2500T uses Intel Socket 1155. Memory channels differ (triple versus dual), and ECC support is exclusive to the Xeon. The i5-2500T includes integrated graphics (Intel HD 2000); the Xeon has none. PCIe generation differs (Gen 2 versus Gen 3 with 16 lanes). Transistor counts and die sizes diverge significantly, as detailed above. The i5-2500T has a smaller L3 cache (6 MB versus 8 MB). Both CPUs have locked multipliers, ruling out overclocking via multiplier adjustment. Neither has a launch MSRP listed in the data.

The release dates are nearly two years apart, with the Xeon launching March 2009 and the i5-2500T January 2011. This generational gap explains why the newer Sandy Bridge part achieves comparable performance while consuming 85W less power, the 32 nm process node delivers a fundamental efficiency advantage over the older 45 nm design.

Head-to-Head Benchmarks

The Xeon W3520 wins all five head-to-head comparisons, but the margins are remarkably tight. In Cinebench R15 multi-core, the Xeon scores 252 against the i5-2500T’s 250, a 0.8% advantage, the largest margin in the entire set. Cinebench R20 multi-core shows the Xeon at 1052 versus 1045, a 0.7% lead. Single-core R20 results are nearly identical: 148 for the Xeon, 147 for the i5-2500T, again a 0.7% gap.

The R23 tests produce the smallest margins. Multi-core R23 has the Xeon at 2505 and the i5-2500T at 2489, a 0.6% difference. Single-core R23 follows the same pattern: 353 versus 351, also 0.6%. Across all five benchmarks, the Xeon’s largest win is 2 points (in R23 multi-core), and its smallest is 1 point (in R20 single-core and R23 single-core). These are essentially rounding errors in real-world terms, yet the pattern is consistent, the Xeon never loses a single test.

The average benchmark scores reinforce the pattern: the Xeon’s 862 average is 6 points above the i5-2500T’s 856. Both CPUs sit at the 23rd percentile of all CPUs, meaning they occupy the same performance tier relative to the broader market. The nearest rivals for the Xeon include the Core i5-3470T at 863 (0.1% ahead) and the Xeon X3460 at 866 (0.5% ahead). For the i5-2500T, the Core i5-5250U matches at 856 (0.1% behind) and the Xeon X5492 sits at 852 (0.5% behind).

Where Each One Wins

The Xeon W3520 wins on raw compute across every benchmark in the data set, but the margins are so slim that the only meaningful victory is consistency, it never trails, even in single-threaded tests where the i5-2500T’s higher 3.30 GHz boost clock should give it an edge. The Xeon’s 8 MB of L3 cache and 8 threads likely contribute to this consistent, if marginal, superiority. The Xeon also wins decisively on platform features: ECC memory support and triple-channel DDR3 make it the appropriate choice for workstation or server builds where data integrity and memory bandwidth are non-negotiable, even if the Cinebench scores do not reflect a large performance gap.

The i5-2500T wins decisively on efficiency. Its 45W TDP versus the Xeon’s 130W means it can be cooled by simpler, quieter solutions and integrated into smaller form factors. The integrated Intel HD 2000 graphics eliminate the need for a discrete GPU in basic desktop tasks. The dual-channel memory bus is sufficient for most desktop workloads, and the 32 nm process node indicates a modern design that achieves parity with the older Xeon while consuming 65% less power. For desktop users building a low-power system, the i5-2500T is the clear pick, it sacrifices only 0.6-0.8% in Cinebench performance while delivering dramatic power savings and integrated graphics.

The data suggests a split decision: the Xeon W3520 for legacy Socket 1366 workstation platforms that require ECC and triple-channel memory, and the i5-2500T for new desktop builds prioritizing power efficiency and integrated graphics. Neither chip offers a compelling reason to choose it for raw speed, as both sit at the 23rd percentile and trade blows within a 6-point average benchmark range. The deciding factors are platform compatibility and power budget, not performance, the benchmarks show these two CPUs are effectively peers despite their architectural differences.