CPU Comparison
Intel Core i5-2405S
Core i7-965
PERFORMANCE BENCHMARKS
Analysis: Intel Core i5-2405S vs Intel Core i7-965
The Intel Core i7-965 and Intel Core i5-2405S represent two distinct eras of desktop computing, yet benchmark results place them in a statistical dead heat. The data shows the i5-2405S edges out the older i7-965 in every head-to-head Cinebench test, albeit by margins of less than one percent. Despite the i7-965's higher clock speeds and Hyper-Threading, the architectural efficiency of Sandy Bridge allows the i5-2405S to close the gap entirely, resulting in an average benchmark score of 991 for the i5 against 993 for the i7. Both processors sit at the 27th percentile among all CPUs, indicating they occupy the same performance tier in modern workloads.
Head-to-Head Benchmarks
The most telling result is the Cinebench R23 multi-core test, where the i5-2405S scores 2890 against the i7-965's 2886, a delta of only -0.1%. This is particularly significant because the i7-965 possesses 8 threads versus the i5-2405S's 4 threads, yet the newer architecture's superior instruction handling neutralizes that advantage. The single-core R23 test follows the same pattern, with the i5-2405S posting 408 versus the i7-965's 407, a -0.2% difference. This near-identical single-threaded performance is notable given the i7-965's higher base clock of 3.20 GHz compared to 2.50 GHz on the i5-2405S.
The Cinebench R20 results reinforce the trend. In multi-core, the i5-2405S scores 1213 while the i7-965 scores 1212, a razor-thin -0.1% margin. The R20 single-core test shows the largest relative gap of the entire suite, with the i5-2405S winning 171 to 170, a -0.6% difference. Even in the older R15 multi-core test, the i5-2405S takes the win at 291 versus 290, again a -0.3% margin. Across all five head-to-head benchmarks, the i5-2405S claims victory, totaling 5 wins for the i5-2405S and 0 for the i7-965.
The practical interpretation is that neither CPU offers a meaningful performance advantage over the other in Cinebench workloads. The largest delta between any two corresponding scores is -0.6%, which falls well within run-to-run variance for most benchmark software. When comparing against their nearest rivals, both CPUs sit at the same level as the Intel Core i7-960, Intel Xeon W3565, and AMD Phenom II X6 1065T, all averaging 993 points. The i5-2405S is listed as -0.2% behind the i7-965 in the rival comparison, yet it wins all head-to-head tests, illustrating that the aggregate average score obscures the per-test outcomes.
FAQ
Q: Which processor has the higher average benchmark score?
A: The Intel Core i7-965 holds a marginal edge with an average benchmark score of 993, while the Intel Core i5-2405S trails at 991. This 2-point difference is less than 0.2% and is statistically insignificant.
Q: Does the i7-965's support for 8 threads provide a multi-core advantage?
A: No. Despite having 8 threads versus the i5-2405S's 4 threads, the i7-965 loses every multi-core Cinebench test. In Cinebench R23 multi-core, the i5-2405S scores 2890 compared to the i7-965's 2886.
Q: What is the largest performance gap between the two CPUs?
A: The largest gap occurs in Cinebench R20 single-core, where the i5-2405S scores 171 and the i7-965 scores 170, representing a -0.6% difference. All other gaps are -0.3% or smaller.
Q: How do these CPUs compare to their nearest rivals?
A: Both CPUs are essentially tied with the Intel Core i7-960, Intel Xeon W3565, and AMD Phenom II X6 1065T, all of which have an average score of 993. The i5-2405S shows a -0.2% delta against all three, while the i7-965 shows a 0% delta.
Q: Which CPU has a higher boost clock?
A: The Intel Core i7-965 has a boost clock of 3.47 GHz, surpassing the i5-2405S's boost clock of 3.30 GHz. However, this 0.17 GHz advantage does not translate into a benchmark win for the i7-965.
Q: Are there any benchmark results where the i7-965 wins?
A: In the five head-to-head Cinebench tests provided, the i7-965 records zero wins. The i5-2405S wins all five tests, though the margins are consistently under one percent.
The Verdict
From a pure performance standpoint, the data offers no compelling reason to choose either CPU over the other. The i5-2405S wins every measured benchmark, but the margins are so narrow that they fall within typical measurement noise. The i7-965's higher average score of 993 versus 991 for the i5-2405S is contradicted by the head-to-head results, where the i5-2405S consistently outperforms. For workloads that mirror Cinebench's rendering tasks, the i5-2405S is the safer pick based on its 5-0 head-to-head record. However, the i7-965's unlocked multiplier allows overclocking, which could potentially widen its performance envelope beyond stock settings, though no overclocked benchmarks are present in the data.
The i5-2405S offers a significantly lower thermal design power of 65 watts compared to the i7-965's 130 watts, making it the more efficient choice for systems where cooling and power draw are concerns. The i5-2405S also integrates Intel HD 3000 graphics, whereas the i7-965 has no integrated graphics, requiring a discrete GPU for any display output. For users with existing LGA 1366 platforms, the i7-965 remains a viable option, but for new builds, the i5-2405S on LGA 1155 provides comparable performance with newer platform features. The percentile ranking places both at 27%, meaning they are outperformed by roughly 73% of all CPUs in the database, indicating that neither is a high-performance choice by modern standards.
Specification Differences
The core count is identical at 4 for both CPUs, but the thread count diverges: the i7-965 offers 8 threads through Hyper-Threading, while the i5-2405S is limited to 4 threads. Base clocks differ notably, with the i7-965 running at 3.20 GHz against the i5-2405S's 2.50 GHz. Boost clocks are closer, with the i7-965 reaching 3.47 GHz and the i5-2405S hitting 3.30 GHz. The thermal design power presents a major difference, as the i7-965 draws 130 watts while the i5-2405S draws only 65 watts. The socket types are incompatible: the i7-965 uses Intel Socket 1366, while the i5-2405S uses Intel Socket 1155.
Memory support also differs, with the i7-965 utilizing a triple-channel DDR3 bus and the i5-2405S using a dual-channel DDR3 bus. PCIe capability favors the i5-2405S, which supports Gen 3 with 16 lanes (CPU only), while the i7-965 is limited to Gen 2. The i5-2405S includes integrated Intel HD 3000 graphics, a feature absent from the i7-965. The i7-965 has an unlocked multiplier for overclocking, whereas the i5-2405S is locked. The i7-965 was released on 2008-11-16, while the i5-2405S followed on 2011-05-21, reflecting the generational gap between Nehalem and Sandy Bridge.
Architecture Differences
The i7-965 is built on Intel's Nehalem architecture with the Bloomfield codename, fabricated on a 45 nm process node. The i5-2405S uses the newer Sandy Bridge architecture with the same codename, produced on a 32 nm process. Transistor counts show a significant jump, with the i7-965 containing 731 million transistors on a 263 mm² die, while the i5-2405S packs 1,160 million transistors on a smaller 216 mm² die. This density increase explains how the i5-2405S achieves similar performance at lower clock speeds and power consumption.
Cache hierarchies are similar in structure but not in size. Both CPUs feature 64 KB of L1 cache per core and 256 KB of L2 cache per core. The L3 cache differs, with the i7-965 providing 8 MB shared across all cores, while the i5-2405S offers 6 MB shared. The i7-965 belongs to the Core i7 Extreme (Bloomfield) generation, while the i5-2405S is part of the Core i5 (Sandy Bridge) generation. Both CPUs support DDR3 memory and do not support ECC memory. The i7-965's part number is SLBCJ, and the i5-2405S's is SR0BB. Both are end-of-life products, and neither has a recorded launch MSRP in the data.