Intel Core i5-2550K vs Intel Core i7-2720QM Comparison

The Intel Core i5-2550K and Intel Core i7-2720QM are both Sandy Bridge parts from Intel, but they target completely different platforms. The i5-2550K is a desktop processor with an unlocked multiplier, while the i7-2720QM is a mobile chip with Hyper-Threading. Despite the i7’s extra threads, the data shows a decisive sweep for the desktop part across every benchmark recorded, with the largest margins appearing in Geekbench tests.

Head-to-Head Benchmarks

The head-to-head results are unambiguous: the i5-2550K wins all seven recorded comparisons. The closest contests come in the Cinebench suite, where the i5 leads by a consistent margin of roughly 6%. In Cinebench R15 multi-core, the i5 scores 365 against the i7’s 344, a 6.1% advantage. That same 6.1% delta appears in Cinebench R20 multi-core, with scores of 1523 versus 1435. Single-core tests follow a similar pattern: Cinebench R20 single-core shows a 6.4% lead (215 vs 202), and Cinebench R23 single-core shows 6.2% (512 vs 482). The i5’s multi-core advantage in Cinebench R23 is also 6.2%, scoring 3628 against 3417.

The story changes dramatically in Geekbench. The i5-2550K’s lead expands to 36.5% in Geekbench multi-core, posting 2096 versus the i7’s 1535. The single-core Geekbench gap is even larger at 44%, with the i5 scoring 697 and the i7 managing only 484. This huge disparity suggests the i5’s higher clock speeds matter far more than the i7’s extra threads in this particular workload. The i7’s Hyper-Threading does not compensate for its lower base and boost clocks in these tests.

What is notable is that the i7-2720QM’s additional threads yield no benchmark wins. Even in multi-threaded Cinebench tests, where the extra threads should theoretically help, the i5 maintains a clear edge. The data implies that the i5’s 3.40 GHz base and 3.80 GHz boost clocks overwhelm the i7’s 2.20 GHz base and 3.30 GHz boost, even when the i7 has twice the thread count. The average benchmark scores reflect this overall trend, with the i5 averaging 1136 and the i7 averaging 1128, a razor-thin 0.7% difference that belies the wide variance in individual tests.

FAQ

Q: Which processor has a higher average benchmark score?

A: The Intel Core i5-2550K has an average benchmark score of 1136, while the Intel Core i7-2720QM scores 1128. The difference is less than 1%, placing both chips at the 32nd percentile of all CPUs.

Q: Does the i7-2720QM’s Hyper-Threading help it win any benchmarks?

A: No. The i7-2720QM has 8 threads versus the i5-2550K’s 4 threads, but the i5 wins all seven head-to-head benchmarks. The closest margin is 6.1% in Cinebench R15 multi-core, and the largest is 44% in Geekbench single-core.

Q: How large is the single-core performance gap between the two?

A: The i5-2550K leads by 6.4% in Cinebench R20 single-core, 6.2% in Cinebench R23 single-core, and 44% in Geekbench single-core. The Geekbench margin is the largest of any test in the comparison.

Q: Are both processors built on the same manufacturing process?

A: Yes. Both use Intel’s 32 nm process node, have 1,160 million transistors, and feature a 216 mm² die size. They also share the Sandy Bridge architecture and codename.

Q: Do the two processors have the same cache configuration?

A: They have identical cache layouts: 64 KB of L1 per core, 256 KB of L2 per core, and 6 MB of shared L3 cache. Neither supports ECC memory, and both use dual-channel memory buses.

Q: What is the TDP difference between the desktop and mobile parts?

A: The i5-2550K has a TDP of 95 watts, while the i7-2720QM has a TDP of 45 watts. This reflects the i5’s desktop design versus the i7’s mobile focus, despite the i7 having more threads.

Architecture Differences

Both processors are built on Intel’s Sandy Bridge architecture, fabricated on a 32 nm process at Intel’s foundry. They share identical transistor counts of 1,160 million and die sizes of 216 mm². The core architecture is the same, with each chip featuring 4 physical cores. The key architectural divergence is threading: the i5-2550K supports 4 threads, while the i7-2720QM supports 8 threads via Hyper-Threading. This makes the i7 a more complex scheduling target, but the benchmark data shows no benefit in the tested workloads.

Memory support differs in documentation. The i5-2550K supports DDR3 memory with a rated bandwidth of 25.6 GB/s on a dual-channel bus. The i7-2720QM’s memory support field is not specified in the data, though it does list a dual-channel memory bus. The i5 also has explicit PCIe support described as Gen 2 with 16 lanes (CPU only), while the i7’s PCIe configuration is not listed. The i7 includes integrated graphics in the form of Intel HD 3000, whereas the i5-2550K has no integrated graphics listed at all. This is a significant architectural difference: the i5 relies entirely on a discrete GPU, while the i7 can drive a display without one.

The unlocked multiplier is another critical architectural feature. The i5-2550K has an unlocked multiplier, enabling overclocking, while the i7-2720QM’s multiplier is locked. This means the i5’s already superior clock speeds can be pushed further, widening the performance gap beyond stock settings. The i7’s mobile socket (Intel BGA 1224) is soldered, making it impractical for user upgrades, while the i5 uses the desktop-friendly Intel Socket 1155.

Specification Differences

The two processors differ in several key specifications. The most obvious is clock speed: the i5-2550K runs at 3.40 GHz base and 3.80 GHz boost, while the i7-2720QM runs at 2.20 GHz base and 3.30 GHz boost. This 1.20 GHz base clock gap is substantial and explains much of the performance delta. Thread count also differs, with the i5 offering 4 threads and the i7 offering 8. The TDP is dramatically different: 95 watts for the i5 versus 45 watts for the i7, reflecting their desktop and mobile market segments.

The sockets are incompatible: the i5 uses Intel Socket 1155, while the i7 uses Intel BGA 1224. The i5’s launch MSRP was $235, while the i7 has no listed launch MSRP. The i5 has an unlocked multiplier and part number SR0QH, whereas the i7 has a locked multiplier and part number SR00W. Integrated graphics are present only on the i7 (Intel HD 3000); the i5 lists none. Memory bandwidth is specified for the i5 at 25.6 GB/s, but not for the i7. The i5’s release date is 2012-01-29, while the i7’s is earlier at 2011-01-02. Both are end-of-life products.

Where Each One Wins

The i5-2550K wins every benchmark in the comparison, so the use-case split is more about the nature of the wins than the existence of them. The i5’s smallest victories are in Cinebench multi-core tests, where it leads by 6.1% to 6.2%. These are the workloads where the i7’s extra threads come closest to closing the gap. If a user is running heavily multithreaded applications like video rendering, the i7’s deficit is at its smallest, though it still loses. The i5’s largest wins are in Geekbench, particularly single-core, where it leads by 44%. This suggests the i5 is overwhelmingly better for single-threaded tasks like everyday responsiveness, legacy software, and lightly threaded games.

The i7-2720QM’s only advantage is in power consumption and platform integration. Its 45-watt TDP is less than half of the i5’s 95 watts, making it suitable for laptops where thermal and power budgets are tight. The integrated Intel HD 3000 graphics mean the i7 can function without a discrete GPU, which is impossible for the i5. The i7 also has Hyper-Threading, which the data shows does not help in these benchmarks but could theoretically aid in other, untested multithreaded scenarios. For a mobile user requiring a complete, low-power package, the i7 is the only choice, but it is not a performance winner.

The Verdict

The data is clear: the Intel Core i5-2550K is the superior processor in every measured metric. It wins all seven head-to-head benchmarks, with margins ranging from 6.1% to 44%. Its higher clock speeds, unlocked multiplier, and desktop platform give it a decisive edge in both single-core and multi-core workloads. The i7-2720QM’s Hyper-Threading does not overcome the clock disadvantage, and its lower TDP is its only meaningful strength. Anyone building a desktop should choose the i5-2550K without hesitation, as it offers better performance in every recorded test. The i7-2720QM is only appropriate for a laptop user who needs a quad-core Sandy Bridge chip with integrated graphics and cannot use a desktop part. Even then, the i7’s performance is strictly lower, so the choice is dictated by form factor, not capability. Both chips sit at the 32nd percentile of all CPUs, but the i5 does so with far more headroom for overclocking. The verdict, based solely on the numbers, is a 7-0 sweep for the i5-2550K.