Intel Core i7-920 vs Intel Xeon W3520 Comparison

Head-to-Head Benchmarks

The recorded data shows a consistent, if narrow, advantage for the Intel Xeon W3520 across every benchmark in the comparison set. The Xeon wins all five head-to-head tests, with deltas ranging from 2.4% to 2.8%. This is not a dramatic gap, but it is a uniform one, and uniformity itself is informative: it suggests the performance difference is structural rather than workload-dependent.

The smallest margin appears in Cinebench R15 multicore, where the Xeon W3520 scores 252 against the Core i7-920's 246, a 2.4% difference. The largest margin is in Cinebench R20 single-core, where the Xeon posts 148 versus 144, a 2.8% gap. The other three tests, Cinebench R20 multicore, Cinebench R23 multicore, and Cinebench R23 single-core, all land at 2.6% deltas. For R20 multicore, the numbers are 1052 against 1025; for R23 multicore, 2505 against 2442; and for R23 single-core, 353 against 344.

What stands out is the consistency across both single-threaded and multi-threaded workloads. The Xeon does not merely win in one category; it wins in both, and by nearly the same proportion. That pattern implies the advantage is not tied to cache scaling or core count, since both chips share identical core and thread counts. Instead, it points to small differences in how the two processors sustain their clock behavior or manage thermal headroom during the test runs. The base clocks are identical at 2.67 GHz for both, and the boost clocks are identical at 2.93 GHz, so the measured delta must come from behavior under load, not from the advertised specifications.

The average benchmark scores reinforce this reading. The Xeon W3520 carries an average score of 862, while the Core i7-920 sits at 840. That is a 22-point gap, roughly 2.6%, which aligns almost perfectly with the head-to-head deltas. The Xeon also holds a slightly better percentile position: it ranks in the 23rd percentile of all CPUs, while the Core i7-920 ranks in the 22nd percentile. In percentile terms, both are firmly in the lower-middle range of the database, which makes sense for processors from this generation, but the Xeon is consistently a step ahead.

The nearest-rival data places both chips in similar company. The Xeon W3520's closest competitor is the Intel Core i5-3470T, which scores 863, just 0.1% above the Xeon. The AMD A8-7650K and Intel Core i7-4500U trail by 0.2% and 0.3% respectively, while the Intel Xeon X3460 sits 0.5% ahead. For the Core i7-920, the nearest rival is the Intel Xeon X5470 at 839, just 0.1% below, with the Intel Core i5-3380M and Intel Core i5-5200U both 0.2% ahead, and the AMD FX-8800P 0.3% behind. These reference points show that both chips occupy a tight performance band, but the Xeon W3520 sits at the upper edge of that band while the i7-920 sits near the lower edge.

The Verdict

The data points to a straightforward conclusion: the Intel Xeon W3520 is the faster processor in this pairing, and it wins every measured test. The margins are small, between 2.4% and 2.8%, but they are consistent across single-core and multi-core workloads. For anyone choosing between these two based purely on benchmark results, the Xeon W3520 is the correct pick. It delivers more Cinebench performance in every recorded scenario, and its average score of 862 versus 840 confirms that the head-to-head results are not an artifact of a single test.

However, the choice is not purely about performance. The Core i7-920 is a desktop part, while the Xeon W3520 is aimed at the server and workstation segment. That distinction matters for platform decisions. The Xeon supports ECC memory, which the Core i7-920 does not. For a workstation running long compute jobs or a small server handling data integrity sensitive workloads, ECC support is a meaningful feature. The Core i7-920, by contrast, lacks ECC entirely, which limits its appeal in those scenarios.

The launch timing also favors the Core i7-920 in one narrow sense: it appeared earlier, with a release date in 2008, while the Xeon W3520 arrived in 2009. That earlier release does not affect performance, but it explains why the desktop part may be more familiar in the used market. Both processors are end-of-life, so neither is a new purchase option. Between the two, the Xeon W3520 offers slightly better measured performance and adds ECC memory support, making it the stronger choice for workstation use. The Core i7-920 remains a viable desktop processor, but the database shows no benchmark category where it outperforms the Xeon.

Architecture Differences

Both processors are built on the same fundamental architecture. They share the Nehalem architecture, the Bloomfield codename, and the 45 nm process node. Intel manufactured both, and both use 731 million transistors on a 263 mm² die. The cache hierarchy is identical as well: 64 KB of L1 per core, 256 KB of L2 per core, and 8 MB of shared L3. Neither chip includes integrated graphics, and both use the Intel Socket 1366 interface with PCIe Gen 2 support.

The architectural similarity is so complete that the recorded differences must come from segmentation rather than design. The Xeon W3520 is classified under the Xeon (Bloomfield) generation, while the Core i7-920 falls under Core i7 (Bloomfield). This is the key architectural distinction in the data: the same silicon, validated and marketed for different market segments. The Xeon targets server and workstation reliability, which explains its ECC memory support. The Core i7-920 targets desktop enthusiasts, which explains the absence of ECC.

ECC memory support is the one architectural feature that genuinely separates the two. The Xeon W3520 lists ECC memory as supported, while the Core i7-920 does not. This is not a performance difference, but it is a capability difference. Error-correcting memory can detect and correct data corruption, which matters in compute environments where a silent bit flip could corrupt results. The Core i7-920 has no such protection in its memory path.

The process node, transistor count, and die size being identical means there is no manufacturing advantage for either chip. They are the same physical design. The measured performance difference, then, is likely the result of binning or firmware behavior. The Xeon W3520 may be selected for slightly better electrical characteristics, which could explain its consistent 2.6% edge in the recorded tests. The database does not show clock differences, since both list the same base and boost clocks, so the margin must come from how each part sustains those clocks under the Cinebench load.

Specification Differences

The two processors differ in only a handful of recorded fields, and every difference traces back to their market segmentation. The market segment field shows the Xeon W3520 as Server/Workstation, while the Core i7-920 is Desktop. This is the root cause of the other differences.

ECC memory support is the most consequential specification gap. The Xeon W3520 supports ECC memory; the Core i7-920 does not. This affects which motherboards and memory modules are appropriate for each chip, and it defines the Xeon's suitability for data integrity sensitive workloads.

The part numbers differ as well. The Xeon W3520 carries the part number SLBEW, while the Core i7-920 carries SLBCHSLBEJ. This is a minor identification detail, but it reflects the different product lines. The release dates also differ: the Core i7-920 launched in 2008, while the Xeon W3520 launched in 2009. The nearly five-month gap suggests Intel introduced the desktop part first and followed with the workstation variant.

All other recorded specifications are identical. Both have 4 cores and 8 threads. Both run at 2.67 GHz base and 2.93 GHz boost. Both have a 130 W TDP. Both use the same socket, architecture, codename, process node, foundry, transistor count, die size, cache configuration, memory type (DDR3), memory bus (triple-channel), and PCIe generation. Neither has a multiplier unlock, and neither has an integrated GPU. The production status is end-of-life for both.

FAQ

Q: Which processor is faster in single-core workloads?

A: The Intel Xeon W3520 wins both single-core tests. It scores 148 versus 144 in Cinebench R20 single-core, a 2.8% delta, and 353 versus 344 in Cinebench R23 single-core, a 2.6% delta.

Q: Do these processors have the same core and thread counts?

A: Yes. Both have 4 cores and 8 threads, and both run at 2.67 GHz base and 2.93 GHz boost clocks.

Q: Does the Core i7-920 support ECC memory?

A: No. The Core i7-920 does not list ECC memory support, while the Xeon W3520 does. This is a key differentiator between the two.

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

A: The Xeon W3520's closest rival is the Intel Core i5-3470T at an average score of 863, just 0.1% higher. The Core i7-920's closest rival is the Intel Xeon X5470 at 839, 0.1% lower. Both chips sit in a tight band around the 840 to 862 average score range.

Q: Are both processors still in production?

A: No. Both are listed as end-of-life. The Core i7-920 launched in 2008, and the Xeon W3520 launched in 2009.

Q: Which chip has the better overall benchmark average?

A: The Xeon W3520 has an average benchmark score of 862, compared to 840 for the Xeon's average. The Xeon W3520 also ranks in the 23rd percentile of all CPUs, one point above the Core i7-920's 22nd percentile.

Where Each One Wins

The Intel Xeon W3520 wins in every recorded benchmark category, so the win split is entirely on its side: 5 wins for the Xeon, 0 for the Core i7-920. There is no test in the database where the Core i7-920 comes out ahead. The Xeon leads in Cinebench R15 multicore, Cinebench R20 multicore and single-core, and Cinebench R23 multicore and single-core. The margins are narrow, between 2.4% and 2.8%, but they are present in every direction the data measures.

The Core i7-920's only advantage is contextual rather than comparative. It is the only one of the pair with a desktop market segment classification, which makes it the more natural fit for a conventional desktop build without workstation pretensions. It lacks ECC memory support, which simplifies the memory selection process for a home or office build. It also launched earlier in 2008, so it appeared in the market earlier than the Xeon. None of these factors appears in the benchmark data as a win, but they define the i7-920's role as the desktop option.

The Xeon W3520, by contrast, is the workstation specialist. It adds ECC memory support, holds a better percentile ranking at 23rd, and holds a higher average benchmark score of 862. For workloads where data integrity matters more than raw speed, and where the small performance edge is welcome, the Xeon is the choice. The data shows a processor that is marginally stronger in every way and additionally equipped for server duty. The Core i7-920 is not without merit, but every measurable performance indicator in the database favors the Xeon.