Intel Core i5-2405S vs Intel Core i7-2635QM Comparison

The Intel Core i7-2635QM and Intel Core i5-2405S are both Sandy Bridge parts from 2011, yet they target different platforms and deliver contrasting benchmark profiles. The data shows a split decision: the i7-2635QM wins 5 of 7 head-to-head tests, while the i5-2405S takes the remaining 2, including a decisive single-core victory. The i7-2635QM edges ahead in all Cinebench tests, with deltas ranging from 3.4% to 3.6%, while the i5-2405S counters with an 18.3% lead in Geekbench single-core and a 3.8% lead in Geekbench multi-core. Both CPUs sit at the 27th percentile among all processors, and their average benchmark scores are nearly identical—995 for the i7-2635QM versus 991 for the i5-2405S. The choice hinges on workload: the i7-2635QM’s extra threads favor Cinebench-style rendering, while the i5-2405S’s higher clocks dominate Geekbench.

The Verdict

From the data alone, the Intel Core i7-2635QM is the pick for multi-threaded rendering workloads. It wins every Cinebench test in the head-to-head comparison—R15 multi-core (301 vs. 291), R20 multi-core (1257 vs. 1213), R20 single-core (177 vs. 171), R23 multi-core (2995 vs. 2890), and R23 single-core (422 vs. 408). Its 4-core, 8-thread configuration provides a consistent 3.4% to 3.6% advantage across all Cinebench iterations, making it the stronger choice for applications that scale with thread count.

The Intel Core i5-2405S, conversely, is the better option for Geekbench-style workloads. It wins Geekbench multi-core with a score of 1425 against 1371, a 3.8% margin, and Geekbench single-core with 541 against 442, an 18.3% margin. This suggests that the i5-2405S’s higher base clock of 2.50 GHz and boost clock of 3.30 GHz—versus 2.00 GHz and 2.90 GHz for the i7-2635QM—translate into superior performance in lightly-threaded or clock-sensitive tasks. The i5-2405S also pulls ahead in average benchmark score comparisons against its nearest rivals, matching the Intel Core i7-960 and i7-965 within 0.2%, while the i7-2635QM ties its closest rival, the Core i7-2920XM, at an identical 995 average score.

In practical terms, the i7-2635QM suits users running Cinebench-heavy render pipelines, while the i5-2405S serves better for general-purpose desktop tasks where single-thread speed matters more. Both are end-of-life parts, so availability and platform compatibility (mobile BGA 1224 versus desktop Socket 1155) will likely dictate the final decision.

Architecture Differences

Both processors share the same Sandy Bridge architecture, 32 nm process node, and Intel foundry. They also feature identical transistor counts of 1,160 million and a die size of 216 mm². The cache hierarchy matches exactly: 64 KB of L1 per core, 256 KB of L2 per core, and 6 MB of shared L3. Both integrate Intel HD 3000 graphics and support dual-channel memory, with ECC memory not supported on either.

The core difference lies in thread count and clock speeds. The i7-2635QM has 4 cores and 8 threads, while the i5-2405S has 4 cores and 4 threads. This means the i7-2635QM can process twice as many threads simultaneously, which explains its Cinebench wins. The i5-2405S compensates with higher clocks—2.50 GHz base and 3.30 GHz boost versus 2.00 GHz and 2.90 GHz—which drives its Geekbench single-core advantage.

Platform and socket differ fundamentally. The i7-2635QM uses Intel BGA 1224, a mobile socket, while the i5-2405S uses Intel Socket 1155, a desktop socket. The i5-2405S also supports PCIe Gen 3 with 16 lanes (CPU only), whereas the i7-2635QM lists no PCIe specification. Memory support is listed only for the i5-2405S (DDR3), while the i7-2635QM’s memory support field is null. Both are end-of-life, with release dates in early and mid-2011 respectively—the i7-2635QM on January 3rd and the i5-2405S on May 22nd.

Head-to-Head Benchmarks

The Cinebench results consistently favor the i7-2635QM. In Cinebench R15 multi-core, the i7-2635QM scores 301 against 291 for the i5-2405S, a 3.4% win. Cinebench R20 multi-core shows a similar pattern: 1257 vs. 1213, a 3.6% margin. The single-core Cinebench tests also go to the i7-2635QM, with R20 single-core at 177 vs. 171 (3.5%) and R23 single-core at 422 vs. 408 (3.4%). Cinebench R23 multi-core repeats the multi-core trend with 2995 vs. 2890, a 3.6% delta.

The i5-2405S strikes back in Geekbench. Geekbench multi-core shows 1425 for the i5-2405S against 1371 for the i7-2635QM, a 3.8% advantage. Geekbench single-core is the largest gap in the entire comparison: 541 vs. 442, an 18.3% margin for the i5-2405S. This single result is nearly five times larger than any other delta in either direction, highlighting a fundamental strength in clock-for-clock performance.

The win count is 5 for the i7-2635QM and 2 for the i5-2405S, but the magnitude of the i5-2405S’s Geekbench single-core win outweighs its loss in frequency. The i7-2635QM’s Cinebench wins are all narrow—under 4%—while the i5-2405S’s single-core Geekbench win is over 18%. In average benchmark score, the i7-2635QM posts 995, just 4 points above the i5-2405S’s 991.

FAQ

Q: Which CPU has more threads?

A: The Intel Core i7-2635QM has 8 threads, while the Intel Core i5-2405S has 4 threads. Both have 4 cores.

Q: What is the performance difference in Geekbench single-core?

A: The i5-2405S leads by 18.3%, scoring 541 against the i7-2635QM’s 442.

Q: How do they compare in Cinebench R23 multi-core?

A: The i7-2635QM wins with a score of 2995, beating the i5-2405S’s 2890 by 3.6%.

Q: Are both CPUs on the same socket?

A: No. The i7-2635QM uses Intel BGA 1224 (mobile), while the i5-2405S uses Intel Socket 1155 (desktop).

Q: Which CPU has a higher boost clock?

A: The i5-2405S has a boost clock of 3.30 GHz, compared to 2.90 GHz for the i7-2635QM.

Q: Do they share the same integrated graphics?

A: Yes, both feature Intel HD 3000 integrated graphics.

Where Each One Wins

The i7-2635QM wins in all Cinebench tests—R15 multi-core, R20 multi-core, R20 single-core, R23 multi-core, and R23 single-core. This makes it the superior choice for Cinebench-based rendering workloads, where its 8 threads provide a measurable edge. The margins are consistent, ranging from 3.4% to 3.6%, indicating that the thread advantage is stable across different Cinebench versions. If your workflow relies on Cinebench scores as a proxy for 3D rendering or multi-threaded content creation, the i7-2635QM is the data-backed pick.

The i5-2405S wins in Geekbench multi-core and single-core. The single-core win is particularly striking at 18.3%, suggesting that the i5-2405S’s higher clock speeds (2.50 GHz base, 3.30 GHz boost) make it far more responsive in single-threaded tasks. The Geekbench multi-core win, though smaller at 3.8%, still shows that the i5-2405S can outpace the i7-2635QM even when all cores are active, likely due to its clock advantage overcoming the thread deficit. For general desktop use, web browsing, office applications, or any workload that favors higher clocks over extra threads, the i5-2405S is the stronger performer.

Specification Differences

The table below lists only the fields where the two processors differ:

| Field | Intel Core i7-2635QM | Intel Core i5-2405S |

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

| Threads | 8 | 4 |

| Base Clock | 2000.00 MHz | 2500.00 MHz |

| Boost Clock | 2.90 GHz | 3.30 GHz |

| TDP | 45 W | 65 W |

| Socket | Intel BGA 1224 | Intel Socket 1155 |

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

| Memory Support | Not specified | DDR3 |

| PCIe | Not specified | Gen 3, 16 Lanes (CPU only) |

| Market Segment | Mobile | Desktop |

| Release Date | 2011-01-03 | 2011-05-22 |

| Part Number | SR030 | SR0BB |

| Geekbench Multi-core | 1371 | 1425 |

| Geekbench Single-core | 442 | 541 |

| Cinebench R15 Multi-core | 301 | 291 |

| Cinebench R20 Multi-core | 1257 | 1213 |

| Cinebench R20 Single-core | 177 | 171 |

| Cinebench R23 Multi-core | 2995 | 2890 |

| Cinebench R23 Single-core | 422 | 408 |

| Avg Benchmark Score | 995 | 991 |

Both CPUs share identical cores (4), L1 cache (64 KB per core), L2 cache (256 KB per core), L3 cache (6 MB shared), process node (32 nm), transistors (1,160 million), die size (216 mm²), memory bus (dual-channel), ECC support (false), integrated graphics (Intel HD 3000), multiplier lock (false), and production status (end-of-life).