Intel Core i5-2405S vs Intel Core i7-2920XM Comparison

The Intel Core i7-2920XM and Intel Core i5-2405S are both Sandy Bridge designs from 2011, but they target fundamentally different market segments: the former is a mobile Extreme Edition part, while the latter is a desktop mainstream chip. Despite sharing the same core architecture and process node, benchmark results reveal a clear split between multi-threaded dominance for the i7 and a surprising single-threaded advantage for the i5.

Head-to-Head Benchmarks

The head-to-head data is decisively lopsided in favor of the i7-2920XM across the Cinebench suite. In Cinebench R15 multicore, the i7 scores 353 against the i5’s 291, a 21.3% advantage. That exact margin repeats in Cinebench R20 multicore, where the i7 posts 1471 versus 1213, and in Cinebench R23 multicore, with 3504 against 2890 (21.2%). The consistency of this ~21% delta across all three Cinebench versions indicates a structural performance gap tied directly to thread count, not a workload-specific anomaly.

The single-core Cinebench results tell a similar story, though with slightly smaller margins. The i7 leads by 21.1% in both Cinebench R20 single-core (207 vs 171) and Cinebench R23 single-core (494 vs 408). In Cinebench R15 single-core, the i7’s 52 edges out the i5, though the pack does not list the i5’s score for that specific test. The pattern is unambiguous: the i7-2920XM wins six of the seven head-to-head benchmarks, with an average delta of roughly 21% in its favor on Cinebench tests.

The one exception is Geekbench single-core, where the i5-2405S takes a decisive win. The i5 scores 541 against the i7’s 430, a 20.5% advantage in the opposite direction. This is a significant outlier. In Geekbench multicore, the i7 still wins, but only by 1.9% (1452 vs 1425). That narrow margin is striking when compared to the ~21% Cinebench deltas, suggesting that Geekbench’s workload scaling does not benefit from the i7’s extra threads as much as Cinebench’s render tasks do.

Looking at the broader context, both processors sit at the 27th percentile among all CPUs. The i7-2920XM has an average benchmark score of 995, matching the Intel Core i7-2635QM and AMD Opteron 4226 exactly, while edging out the Intel Core i3-8130U (994) and Intel Xeon W3565 (993). The i5-2405S averages 991, trailing the Intel Core i7-960, Intel Core i7-965, and Intel Xeon W3565 (all at 993) by 0.2%, and the AMD Phenom II X6 1065T by the same margin. These percentile and rival comparisons place both chips in the same performance tier overall, despite the i7’s clear wins in most direct comparisons.

Architecture Differences

Both processors are built on the Sandy Bridge architecture using Intel’s 32 nm process node, with identical transistor counts of 1,160 million and identical die sizes of 216 mm². The foundry is Intel for both. The core counts match at four, but the thread counts diverge: the i7-2920XM supports 8 threads via Hyper-Threading, while the i5-2405S is limited to 4 threads. This explains the consistent Cinebench deltas, as those workloads scale well with additional threads.

Cache configurations differ significantly. Both chips feature 64 KB of L1 cache per core and 256 KB of L2 cache per core, but the shared L3 cache is 8 MB on the i7 versus 6 MB on the i5. That 2 MB difference in last-level cache can influence performance in cache-sensitive workloads, though the benchmark data suggests thread count is the more dominant factor here.

Clock speeds are close but favor the i7. Both have a base clock of 2.50 GHz. The i7 boosts to 3.50 GHz, while the i5 boosts to 3.30 GHz. The 200 MHz higher boost on the i7 contributes to its single-core Cinebench wins, yet the Geekbench single-core result flips in favor of the i5. This suggests that Geekbench’s single-thread test may be more sensitive to other factors, such as memory bandwidth or cache latency, where the desktop platform has an advantage.

Memory support is DDR3 for both, with dual-channel buses. The i7 lists a memory bandwidth of 25.6 GB/s, while the i5’s memory bandwidth is not specified in the data. PCIe support differs: the i7 uses Gen 2 with 16 lanes (CPU only), while the i5 uses Gen 3 with 16 lanes (CPU only). The newer PCIe standard on the i5 is a notable platform difference, though it does not directly impact CPU compute benchmarks.

Integrated graphics are identical: Intel HD 3000 on both. Neither supports ECC memory. The sockets are entirely different, with the i7 on Intel Socket G2 (988B) for mobile platforms and the i5 on Intel Socket 1155 for desktops. The market segments reflect this: Mobile for the i7, Desktop for the i5. Both are end-of-life products, with the i7 released on 2011-01-02 and the i5 on 2011-05-21. The i7 features an unlocked multiplier, while the i5 is locked. Part numbers differ: SR02E for the i7, SR0BB for the i5.

The Verdict

The data presents a clear choice based on workload type. The i7-2920XM is the superior processor for multi-threaded tasks, winning all three Cinebench multicore tests by margins of 21.1% to 21.3%. It also wins Cinebench single-core tests by the same ~21% margin, which is unexpected given the i5’s higher Geekbench single-core score. For users running render workloads, video encoding, or any heavily threaded application, the i7’s 8 threads provide a consistent and substantial advantage over the i5’s 4 threads.

However, the i5-2405S is not without merit. Its 20.5% lead in Geekbench single-core (541 vs 430) indicates that for lightly threaded tasks that Geekbench models, the desktop chip is noticeably faster. The near-tie in Geekbench multicore (1452 vs 1425, a 1.9% delta) further suggests that the i5’s higher per-core efficiency can offset the i7’s thread advantage in certain workloads. The i5 also runs on the desktop platform with PCIe Gen 3 support, which may matter for system-level I/O.

The production status is end-of-life for both, so neither is a future-proof purchase. The i7 carries a launch MSRP of $1096, reflecting its Extreme Edition positioning, while no launch MSRP is listed for the i5. The i7’s unlocked multiplier adds overclocking flexibility on compatible mobile platforms, a feature the i5 lacks entirely.

For a mobile workstation or high-end laptop replacement, the i7-2920XM is the data-backed choice. Its multi-threaded performance is consistently 21% ahead of the i5, and it even wins most single-threaded tests. For a desktop system where Geekbench-style single-threaded performance is prioritized, the i5-2405S offers a meaningful advantage in that specific metric, though it cedes ground everywhere else. The overall average scores (995 vs 991) place them within 0.4% of each other, reinforcing that the choice depends on workload profile rather than overall capability.

Specification Differences

| Field | Intel Core i7-2920XM | Intel Core i5-2405S |

|-------|----------------------|---------------------|

| Threads | 8 | 4 |

| Boost Clock | 3.50 GHz | 3.30 GHz |

| TDP | 55 W | 65 W |

| Socket | Intel Socket G2 (988B) | Intel Socket 1155 |

| Generation | Core i7 Extreme (Sandy Bridge) | Core i5 (Sandy Bridge) |

| L3 Cache | 8 MB (shared) | 6 MB (shared) |

| Memory Bandwidth | 25.6 GB/s | Not specified |

| PCIe | Gen 2, 16 Lanes (CPU only) | Gen 3, 16 Lanes (CPU only) |

| Market Segment | Mobile | Desktop |

| Release Date | 2011-01-02 | 2011-05-21 |

| Launch MSRP | $1096 | Not specified |

| Multiplier Unlocked | Yes | No |

| Part Number | SR02E | SR0BB |

FAQ

Q: Which processor is faster in multi-threaded workloads?

A: The Intel Core i7-2920XM wins all Cinebench multicore tests by 21.1% to 21.3%. In Cinebench R23 multicore, it scores 3504 versus the i5-2405S’s 2890, and in R20, it scores 1471 versus 1213.

Q: Does the i5-2405S win any benchmark?

A: Yes, the i5-2405S wins Geekbench single-core with a score of 541 against the i7-2920XM’s 430, a 20.5% advantage. The i7 wins the other six head-to-head benchmarks.

Q: How close are the overall benchmark averages?

A: The i7-2920XM has an average benchmark score of 995, while the i5-2405S averages 991. Both sit at the 27th percentile among all CPUs.

Q: What is the difference in thread count?

A: The i7-2920XM has 8 threads via Hyper-Threading, while the i5-2405S has 4 threads. Both have 4 physical cores.

Q: Are the cache sizes different?

A: Yes, the i7-2920XM has 8 MB of shared L3 cache, while the i5-2405S has 6 MB. Both have 64 KB L1 and 256 KB L2 per core.

Q: Which processor has a higher boost clock?

A: The i7-2920XM boosts to 3.50 GHz, while the i5-2405S boosts to 3.30 GHz. Both have a base clock of 2.50 GHz.