CPU Comparison

The Intel Xeon X3460 and Intel Xeon W3520 are two 45 nm Nehalem-era server processors that, on paper, appear nearly identical. Both pack four cores and eight threads, share the same 8 MB of L3 cache, and target the same server/workstation market. Yet the benchmark data reveals a consistent, if narrow, edge for the X3460 across every single test. This analysis digs into those results, the architectural choices that separate them, and what those differences mean for real-world workloads.

Head-to-Head Benchmarks

The head-to-head data is unambiguous: the Intel Xeon X3460 wins all five benchmark comparisons, though by margins that are remarkably slim. In Cinebench R15 multi-core, the X3460 scores 253 against the W3520’s 252, a delta of just 0.4%. The pattern holds in Cinebench R20 multi-core, where the X3460 posts 1057 versus 1052, a 0.5% advantage. Single-core tests tell the same story, the X3460 leads 149 to 148 in R20 single-core (0.7%) and 355 to 353 in R23 single-core (0.6%). The largest gap appears in R23 multi-core, where the X3460’s 2518 edges out the W3520’s 2505, again by 0.5%.

These deltas are tiny, but they are consistent. The X3460’s average benchmark score of 866 sits just above the W3520’s 862, and the nearest-rival data places the X3460 0.5% ahead of the W3520 in that broader comparison. Interestingly, the W3520’s own nearest-rival list shows it trailing the X3460 by that same 0.5%, confirming the margin from both directions. Neither chip is a performance powerhouse, both sit at the 23rd percentile among all CPUs, but the X3460 is, by every measured metric, the faster processor. The wins are not dramatic; they are the kind of incremental gains that come from clock-speed differences rather than architectural overhauls.

Architecture Differences

The two CPUs share a common Nehalem design, but they are built on different physical implementations. The X3460 uses the Lynnfield codename, while the W3520 is Bloomfield. Both are fabricated on Intel’s 45 nm process, with the X3460 packing 774 million transistors on a 296 mm² die, compared to the W3520’s 731 million transistors on a 263 mm² die. That is a meaningful difference, the X3460 carries roughly 43 million more transistors in a larger silicon area, which likely contributes to its slightly higher clock speeds.

The cache hierarchy is identical on paper: 64 KB of L1 per core, 256 KB of L2 per core, and 8 MB of shared L3. The divergence appears in the memory subsystem. The X3460 supports dual-channel DDR3 with a stated memory bandwidth of 21.3 GB/s. The W3520, by contrast, uses triple-channel DDR3, though the FACT PACK does not list a bandwidth figure for it. This is a crucial distinction: the W3520’s triple-channel setup should theoretically provide more memory bandwidth, yet the X3460 still wins every compute benchmark. This suggests that for the Cinebench workloads tested, memory bandwidth is not the limiting factor, raw clock speed matters more.

The sockets differ as well: the X3460 uses Intel Socket 1156, while the W3520 uses Intel Socket 1366. This is a hard compatibility barrier, they are not interchangeable. The X3460 also specifies PCIe Gen 2 with 16 lanes (CPU only), while the W3520 lists simply PCIe Gen 2 without a lane count. Both support ECC memory and lack integrated graphics. Neither has an unlocked multiplier.

Where Each One Wins

Given that the X3460 wins every benchmark, the question is not where it wins, but why the margins are so thin. The X3460’s base clock is 2.80 GHz against the W3520’s 2.67 GHz, and its boost clock reaches 3.47 GHz versus 2.93 GHz. That 0.54 GHz boost advantage is the most obvious driver of the X3460’s consistent single-core superiority. In single-threaded workloads, the X3460’s higher boost clock gives it a clear edge, 0.7% in R20 and 0.6% in R23, which is exactly what one would expect from a frequency advantage.

Multi-core wins follow the same pattern, but the gaps are slightly smaller (0.4% to 0.5%). This suggests that in fully threaded workloads, the W3520’s triple-channel memory helps close the gap somewhat, though not enough to overcome the clock deficit. The W3520’s higher TDP of 130 watts versus the X3460’s 95 watts is a notable trade-off. The W3520 draws more power, yet still loses on performance. This is a curious result, the extra power does not translate into extra speed. For workloads that are latency-sensitive or lightly threaded, the X3460 is the clear pick. For heavily memory-bound tasks, the W3520’s triple-channel architecture might offer an advantage, but the benchmark data does not capture such a scenario.

Specification Differences

The two processors differ in several key specification fields. The most obvious is clock speed: the X3460 runs at 2.80 GHz base and 3.47 GHz boost, while the W3520 runs at 2.67 GHz base and 2.93 GHz boost. The X3460’s boost clock is a full 0.54 GHz higher, a substantial delta for chips from the same generation. The TDP also diverges significantly, the X3460 is rated at 95 watts, the W3520 at 130 watts. This makes the X3460 the more power-efficient part on paper, especially given its higher performance.

The memory bus is another clear difference: the X3460 uses dual-channel DDR3 with a quoted 21.3 GB/s bandwidth, while the W3520 uses triple-channel DDR3 with no bandwidth figure provided. The sockets are different (1156 for the X3460, 1366 for the W3520), which means they require different motherboards. The transistor count and die size also differ, 774 million transistors on 296 mm² for the X3460 versus 731 million on 263 mm² for the W3520. The X3460 has a launch MSRP of $316; the W3520 has no launch MSRP listed. Release dates differ too: the X3460 launched on September 7, 2009, while the W3520 came earlier, on March 29, 2009. Both are end-of-life parts with ECC memory support and no integrated graphics.

FAQ

Q: Which CPU has the higher boost clock?

A: The Intel Xeon X3460 has a boost clock of 3.47 GHz, compared to the W3520’s 2.93 GHz, a difference of 0.54 GHz.

Q: How do their multi-core Cinebench R23 scores compare?

A: The X3460 scores 2518 in Cinebench R23 multi-core, while the W3520 scores 2505, giving the X3460 a 0.5% lead.

Q: Do both CPUs support ECC memory?

A: Yes, both the X3460 and the W3520 list ECC memory support as a feature.

Q: What is the memory bus difference between the two?

A: The X3460 uses dual-channel DDR3 with a bandwidth of 21.3 GB/s, while the W3520 uses triple-channel DDR3, though no bandwidth figure is listed for it.

Q: Are the two CPUs socket-compatible?

A: No. The X3460 uses Intel Socket 1156, while the W3520 uses Intel Socket 1366.

Q: Which CPU has a higher TDP?

A: The W3520 has a TDP of 130 watts, which is notably higher than the X3460’s 95 watts.

The Verdict

The data points to one clear conclusion: the Intel Xeon X3460 is the better processor. It wins every single benchmark in the head-to-head comparison, from Cinebench R15 to R23, in both single-core and multi-core tests. The margins are narrow, never exceeding 0.7%, but they are consistent across all five tests. The X3460 achieves this with a lower TDP (95 watts versus 130 watts), a higher boost clock (3.47 GHz versus 2.93 GHz), and a smaller memory bus (dual-channel versus triple-channel). It also has a higher average benchmark score (866 versus 862) and sits at the same 23rd percentile among all CPUs.

The W3520 is not a bad processor; it is simply outclassed by a chip that offers more performance while drawing less power. The W3520’s triple-channel memory is its one theoretical advantage, but the benchmark results show no scenario where it translates into a win. For anyone choosing between these two, the X3460 is the obvious pick from a pure performance standpoint. The only caveat is the socket difference, if a system is built around Socket 1366, the W3520 might be the only option, but for new builds, the X3460’s 95-watt TDP and superior clock speeds make it the clear winner. The data does not support any other conclusion.