CPU Comparison

The Intel Xeon E5540 and Intel Core i7-5550U represent two vastly different eras and design philosophies from Intel, yet their benchmark scores land them within a single percentage point of each other. The Xeon is a server-grade Nehalem part from 2009, built for multi-socket workstations with a hefty 80W thermal envelope. The Core i7 is a 2015 Broadwell mobile chip, sipping power at just 15W and designed for ultrathin laptops. While they share the same Intel foundry and DDR3 memory support, their architectures, physical designs, and intended workloads could hardly be more different. The data shows a fascinating collision: a 4-core/8-thread server veteran against a 2-core/4-thread mobile efficiency champion, with the server part edging out a narrow victory across every single benchmark.

Architecture Differences

The most fundamental architectural split is the process node. The Xeon E5540 uses Intel's 45 nm manufacturing process, packing 731 million transistors onto a 263 mm² die. In contrast, the Core i7-5550U is built on a 14 nm process, cramming 1,900 million transistors into a much smaller 133 mm² die. This generational leap in manufacturing density allows the mobile chip to deliver competitive performance while consuming only a fraction of the power.

Core counts tell the next major story. The Xeon E5540 features 4 physical cores with 8 threads via Hyper-Threading, while the Core i7-5550U offers just 2 physical cores and 4 threads. This gives the Xeon a raw parallel-processing advantage in threaded workloads. However, the i7-5550U compensates with significantly higher clock speeds: its base clock is listed as 2000.00 MHz (2.00 GHz) and it boosts to 3.00 GHz, whereas the Xeon runs at a 2.53 GHz base and 2.80 GHz boost.

Cache hierarchies also differ. Both chips share the same per-core L1 (64 KB) and L2 (256 KB) cache allocations, but the Xeon E5540 has a much larger shared L3 cache at 8 MB, double the 4 MB found on the Core i7-5550U. This additional cache is critical for server workloads that frequently access large datasets. Memory support sees the Xeon equipped with triple-channel DDR3 providing 25.6 GB/s bandwidth, while the i7-5550U uses dual-channel DDR3 with a higher 29.9 GB/s peak bandwidth.

The feature sets diverge sharply. The Xeon E5540 supports ECC memory, a requirement for server reliability, and uses the Intel Socket 1366 platform. The Core i7-5550U lacks ECC support, uses Intel BGA 1168 (soldered), and integrates Intel HD 6000 graphics, a feature entirely absent from the Xeon. The i7-5550U also specifies 12 PCIe Gen 2 lanes (CPU only), while the Xeon simply lists PCIe Gen 2 support. The Xeon carries a launch MSRP of $774, while the i7-5550U launched at $426.

The Verdict

Benchmark results indicate the Intel Xeon E5540 is the outright winner in every head-to-head test, but the margins are razor-thin. In Cinebench R15 multi-core, the Xeon scores 240 versus 238 for the i7-5550U, a delta of just 0.8%. The R20 multi-core test shows 1001 against 992, a 0.9% lead. Single-core results follow the same pattern: 141 vs 139 in R20 single-core (1.4% delta) and 336 vs 333 in R23 single-core (0.9% delta). The Xeon wins all five head-to-head benchmarks, but the maximum victory margin is a mere 1.4%.

Given the data, the choice comes down to platform and power, not performance. The Xeon E5540 is the pick for legacy server/workstation builds where ECC memory, triple-channel bandwidth, and the larger 8 MB L3 cache matter. The Core i7-5550U is the clear choice for mobile or low-power embedded applications, where its 15W TDP (versus 80W for the Xeon) and integrated graphics provide capabilities the Xeon simply cannot match. For raw compute in a socketed server board, the Xeon edges ahead; for efficiency and integrated features, the i7-5550U wins decisively.

Where Each One Wins

The Xeon E5540 wins every benchmark contest, but the practical victories are small. Its largest advantage comes in Cinebench R20 single-core, where it leads by 1.4% (141 vs 139). This suggests that even in lightly-threaded tasks, the older Nehalem architecture holds a slight edge in this specific test. The Xeon also demonstrates consistent multi-core wins across R15 (240 vs 238), R20 (1001 vs 992), and R23 (2384 vs 2363), all by roughly 0.8–0.9%.

The Core i7-5550U, despite losing all five head-to-head matchups, wins in areas not captured by these benchmarks. Its integrated Intel HD 6000 graphics provide a display output and basic GPU acceleration that the Xeon lacks entirely. Its 15W TDP makes it viable in fanless or passively-cooled designs, whereas the 80W Xeon demands active cooling. The i7-5550U also has a higher memory bandwidth rating at 29.9 GB/s versus 25.6 GB/s for the Xeon, suggesting it may handle memory-intensive tasks more efficiently despite its dual-channel limitation.

Head-to-Head Benchmarks

The closest contest is Cinebench R15 multi-core, where the Xeon E5540 scores 240 against 238 for the Core i7-5550U. This 0.8% delta represents nearly a tie, showing that the Xeon's two extra cores and 8 MB L3 cache barely offset the i7's superior clock speed and newer architecture. In Cinebench R20 multi-core, the Xeon again prevails with 1001 points versus 992, a 0.9% margin, the same relative gap seen in R23 multi-core (2384 vs 2363, also 0.9%).

The single-core results are equally tight. Cinebench R20 single-core shows the Xeon at 141 and the i7-5550U at 139, giving the Xeon its largest win at 1.4%. Cinebench R23 single-core narrows this to 336 vs 333, a 0.9% edge. Across all five tests, the Xeon's average benchmark score is 820, while the i7-5550U sits at 813, a difference of just 0.9% overall.

The benchmark data places both processors in the 22nd percentile of all CPUs, indicating they are entry-level performers by modern standards. The Xeon's nearest rival is the AMD PRO A10-8750B with an average score of 821 (a -0.1% delta), while the i7-5550U's closest competitor is the Intel Core 2 Extreme QX9775 at 813 (a 0% delta). Both chips sit within a 1% band of the Intel Xeon X3440, which scores 815.

FAQ

Q: Which processor has more cores and threads?

A: The Intel Xeon E5540 has 4 cores and 8 threads, while the Intel Core i7-5550U has 2 cores and 4 threads. The Xeon's average benchmark score of 820 reflects this parallel advantage, edging out the i7's 813.

Q: Do both processors support ECC memory?

A: No. The Xeon E5540 supports ECC memory, consistent with its Server/Workstation market segment. The Core i7-5550U does not support ECC and is classified as a Mobile processor.

Q: What are the integrated graphics capabilities?

A: The Core i7-5550U includes Intel HD 6000 integrated graphics, while the Xeon E5540 has no integrated graphics at all. This makes the i7-5550U suitable for systems requiring a display output without a discrete GPU.

Q: How do their power requirements compare?

A: The Xeon E5540 has a TDP of 80W, while the Core i7-5550U is rated at just 15W. This is a five-fold difference in thermal design power, making the i7-5550U far more suitable for compact or battery-powered devices.

Q: Which chip wins in Cinebench R23 multi-core?

A: The Xeon E5540 wins with a score of 2384 versus 2363 for the Core i7-5550U, a delta of 0.9%. This follows the pattern seen across all five head-to-head benchmarks, where the Xeon wins by margins between 0.8% and 1.4%.

Q: What is the memory bandwidth difference?

A: The Core i7-5550U has a higher memory bandwidth rating at 29.9 GB/s, despite using dual-channel DDR3, compared to the Xeon E5540's triple-channel setup rated at 25.6 GB/s. The i7-5550U also has a smaller 4 MB L3 cache versus the Xeon's 8 MB.