Intel Xeon E5450 vs Intel Xeon E5520 Comparison

The Verdict

The recorded data shows a consistent, though narrow, advantage for the Intel Xeon E5450 across every benchmark in the comparison. The E5450 wins all five head-to-head tests, with margins ranging from 1.8% to 2.4%. The E5520, despite offering twice the thread count, never overtakes the older Harpertown part in any measured workload. For workloads that rely on single-threaded performance or lightly threaded tasks, the E5450 is the clear pick. For workloads that can exploit eight threads, the E5520’s architecture suggests it should be competitive, yet the benchmark results do not show a win in any test. The data indicates the E5450 is the better performer in this specific matchup, but the differences are small enough that platform-level considerations, such as memory support and socket, could reasonably decide the choice.

Architecture Differences

The two processors come from different architectural families. The E5450 uses the Core 2 architecture with the Harpertown codename, built on a 45 nm process with 820 million transistors. Its die is composed of two separate 107 mm² dies. The E5520 uses the Nehalem architecture with the Gainestown codename, also on a 45 nm process, but with 731 million transistors on a single 263 mm² die. Both are end-of-life server and workstation parts from Intel, and both support ECC memory and PCIe Gen 2.

Cache layouts differ substantially. The E5450 has 64 KB of L1 cache per core and 6 MB of L2 cache per die, with no L3 cache. The E5520 also has 64 KB of L1 per core, but its L2 is 256 KB per core, and it adds an 8 MB shared L3 cache. That L3 cache is a significant architectural addition, yet it does not translate into benchmark wins for the E5520 in the measured tests.

Clock speeds also differ. The E5450 runs at a 3.00 GHz base clock with no boost clock listed. The E5520 runs at a 2.27 GHz base clock and can boost to 2.53 GHz. The E5450 has a 0.73 GHz base clock advantage, which likely explains its lead in single-threaded tests.

Thread counts differ. The E5450 has 4 cores and 4 threads. The E5520 has 4 cores and 8 threads thanks to Hyper-Threading. Despite having twice the logical threads, the E5520 does not win a single multicore test.

Memory support differs. The E5450 supports DDR2 and DDR3 depending on the motherboard, with a dual-channel memory bus. The E5520 supports only DDR3, but with a triple-channel memory bus. The E5520’s memory controller is integrated, part of the Nehalem design, while the E5450 relies on the motherboard chipset for memory access.

The E5450 was released in November 2007, while the E5520 followed in March 2009. The E5450 had a launch MSRP of $915. No launch MSRP is recorded for the E5520. Both processors have locked multipliers.

Head-to-Head Benchmarks

The largest margin in the entire comparison is in the Cinebench R20 single-core test. The E5450 scores 130 against the E5520’s 127, a 2.4% advantage. This is the only test where the delta exceeds 2%. The E5450 also wins the Cinebench R15 multicore test by 1.8%, scoring 221 versus 217. That is the narrowest margin recorded.

The three remaining tests are all multicore workloads, and the E5450 wins each by exactly 2%. In Cinebench R20 multicore, the E5450 scores 923 against 905. In Cinebench R23 multicore, the E5450 scores 2198 against 2155. In Cinebench R23 single-core, the E5450 scores 310 against 304, also a 2% delta.

The pattern is clear: the E5450 leads in every category, whether single-core or multi-core. The E5520’s eight threads do not produce a win in any multicore test. This is noteworthy because the E5520’s additional threads should, in theory, help in heavily threaded workloads. The data shows no such benefit materializing in these Cinebench runs.

The average benchmark score tells a similar story. The E5450 has an average score of 756, while the E5520 sits at 742. That is a roughly 1.9% difference in the overall average, consistent with the head-to-head margins.

The percentile rankings are identical. Both processors sit at the 20th percentile among all CPUs in the database. Neither part is a high-flyer by modern standards, but within this pairing, the E5450 is consistently ahead.

FAQ

Q: Which processor has the higher base clock?

A: The Intel Xeon E5450 has a base clock of 3.00 GHz. The Intel Xeon E5520 has a base clock of 2.27 GHz and a boost clock of 2.53 GHz.

Q: Does the E5520 ever win a benchmark in this comparison?

A: No. The E5450 wins all five head-to-head benchmarks. The E5520 records zero wins.

Q: What is the largest performance margin in this comparison?

A: The largest margin is 2.4%, in the Cinebench R20 single-core test, where the E5450 scores 130 versus the E5520’s 127.

Q: How do the thread counts differ?

A: The E5450 has 4 cores and 4 threads. The E5520 has 4 cores and 8 threads.

Q: Do both processors support ECC memory?

A: Yes, both the E5450 and the E5520 support ECC memory.

Q: What memory types does each processor support?

A: The E5450 supports DDR2 and DDR3 depending on the motherboard, with a dual-channel bus. The E5520 supports only DDR3, with a triple-channel bus.

Q: Are both processors still in production?

A: No. Both are listed as end-of-life.

Where Each One Wins

The Intel Xeon E5450 wins every benchmark in this comparison. It wins single-core tests by 2% to 2.4%, and multicore tests by 1.8% to 2%. Its higher base clock of 3.00 GHz gives it an edge in lightly threaded workloads. The Cinebench R20 single-core result, a 2.4% lead, is its strongest showing. For any task that is latency-sensitive or relies on a single thread, the data points to the E5450.

The E5520 does not win a single benchmark. However, its architecture includes features that could matter outside these specific tests. It has an 8 MB shared L3 cache, a triple-channel DDR3 memory bus, and 8 threads. These features do not produce wins in Cinebench, but they could be relevant in memory-bandwidth-sensitive workloads or in scenarios where the operating system can more effectively schedule eight threads. The database records no such wins, so any claim of superiority for the E5520 in other workloads would be speculative based on this data.

The E5450 also holds a slight edge in average benchmark score, 756 versus 742. Its nearest rivals are mobile and low-power desktop parts, including the Intel Core i5-4250U at an identical 756 average score, and the Intel Core i3-5020U at 757, which is 0.2% faster. The E5520’s nearest rivals include the AMD Phenom II X4 B97 at 741 (0.1% faster than the E5520), the Intel Core i5-670 at 741 (0.2% faster), and the Intel Core i7-860S at 740 (0.3% faster). Both processors are firmly in the 20th percentile of all CPUs, indicating they are entry-level performers in the current database.

Specification Differences

The two processors differ in several key specifications. The E5450 uses the Core 2 architecture with the Harpertown codename, while the E5520 uses Nehalem with the Gainestown codename. Both use a 45 nm process, but the E5450 has 820 million transistors across two 107 mm² dies, while the E5520 has 731 million transistors on a single 263 mm² die.

Clock speeds differ: the E5450 runs at 3.00 GHz base with no boost, while the E5520 runs at 2.27 GHz base and 2.53 GHz boost. Thread counts differ: 4 threads for the E5450, 8 for the E5520. Cache differs: the E5450 has 6 MB L2 per die and no L3, while the E5520 has 256 KB L2 per core and 8 MB shared L3. Both have 64 KB L1 per core.

Memory support differs: the E5450 supports DDR2 and DDR3 depending on motherboard, with a dual-channel bus. The E5520 supports only DDR3, with a triple-channel bus. Both support ECC memory. The sockets differ: the E5450 uses Intel Socket 771, while the E5520 uses Intel Socket 1366.

Release dates differ: the E5450 launched in November 2007, the E5520 in March 2009. The E5450 had a launch MSRP of $915; no launch MSRP is recorded for the E5520. Both have locked multipliers, both support PCIe Gen 2, and both are end-of-life server and workstation parts. The part numbers differ as well: SLANQSLBBM for the E5450, and SLBFD for the E5520.