Intel Core 2 Extreme QX9775 vs Intel Core i7-870S Comparison

Where Each One Wins

The benchmark data presents an unusually one-sided picture: the Intel Core 2 Extreme QX9775 wins all five head-to-head comparisons against the Intel Core i7-870S. That said, the margins are razor-thin across the board, with the largest delta being just 0.8% in Cinebench R15 multicore. Neither processor dominates in a meaningful sense; instead, the QX9775 edges ahead in every measured workload, but by margins that fall well within typical run-to-run variance.

The QX9775's wins are consistent but small. In Cinebench R15 multicore, it scores 238 versus 236 for the i7-870S, a 0.8% advantage. In Cinebench R20 multicore, the gap narrows to 992 versus 987, a 0.5% lead. Cinebench R23 multicore shows 2363 versus 2350, again a 0.6% edge. Single-core results are essentially identical: both chips produce 139 in Cinebench R20 single-core, and the QX9775 leads 333 to 331 in Cinebench R23 single-core, a 0.6% margin.

The i7-870S has no benchmark wins at all — zero out of five tests. However, the data suggests this is less about the QX9775 being fundamentally faster and more about the two parts landing in the same performance class. The average benchmark scores reinforce this: the QX9775 averages 813, while the i7-870S averages 809, a difference of 0.5% that mirrors the head-to-head deltas. Both processors sit at the 22nd percentile among all CPUs, meaning they are statistically indistinguishable in overall standing.

For use-case selection, the practical takeaway is that neither chip offers a decisive advantage in any workload type. The QX9775 is marginally better in both multicore and single-core rendering tasks, but the differences are so small that real-world applications would likely perform identically. The i7-870S, with its lower TDP and newer architecture, might be the more sensible choice for sustained workloads where power draw matters, but strictly from benchmark scores, the QX9775 takes every round.

Architecture Differences

The two processors come from different architectural eras, which explains their similar performance despite very different designs. The Core 2 Extreme QX9775 uses the Core 2 architecture on the Yorkfield die, built on Intel's 45nm process. It packs 820 million transistors across a dual-die configuration with a die size of 2x 107 mm². The i7-870S, in contrast, uses the Nehalem architecture on the Lynnfield die, also on 45nm, but with 774 million transistors on a single 296 mm² die.

Cache layouts diverge significantly. The QX9775 features 64 KB of L1 cache per core and 6 MB of L2 cache per die, with no L3 cache. The i7-870S also has 64 KB of L1 per core, but its L2 is 256 KB per core, and it adds 8 MB of shared L3 cache. This means the i7-870S has more total on-chip cache, which typically helps in cache-sensitive workloads, yet the benchmark data does not show it translating into a performance win.

Threading is another major split. The QX9775 is a 4-core, 4-thread part with no Hyper-Threading, while the i7-870S is 4-core, 8-thread with Hyper-Threading enabled. Despite having twice the thread count, the i7-870S still loses in multicore benchmarks, suggesting that its lower base clock of 2.67 GHz (versus 3.20 GHz on the QX9775) outweighs the threading advantage in these specific Cinebench tests. The i7-870S does have a boost clock of 3.60 GHz, but the QX9775 has no boost capability at all, relying solely on its fixed 3.20 GHz.

Memory support differs as well: the QX9775 uses DDR2 (depending on motherboard), while the i7-870S uses DDR3 with dual-channel support. The i7-870S also has ECC memory disabled, whereas the QX9775 supports ECC. PCIe generations differ — the QX9775 is Gen 1, the i7-870S is Gen 2 with 16 lanes from the CPU. The QX9775 has an unlocked multiplier, while the i7-870S is locked. Neither chip has integrated graphics.

Head-to-Head Benchmarks

The closest contest is Cinebench R20 single-core, where both processors score exactly 139, resulting in a 0% delta. This is a pure tie, indicating that per-clock IPC improvements in Nehalem are offset by the QX9775's higher base clock. The QX9775 runs at 3.20 GHz fixed, while the i7-870S boosts to 3.60 GHz, but the single-core scores suggest the boost does not fully compensate for architectural differences in this test.

Cinebench R15 multicore gives the QX9775 its largest win at 0.8% (238 versus 236). This is notable because the i7-870S has eight threads against the QX9775's four. The fact that a 4-thread part beats an 8-thread part in a multicore render suggests the QX9775's higher clock speed and simpler core design are more effective in this workload than Hyper-Threading on the i7-870S.

Cinebench R20 multicore shows a similar story: 992 versus 987, a 0.5% edge for the QX9775. The i7-870S's eight threads do not help it close the gap, even though the test scales well with core count in general. Cinebench R23 multicore follows the same pattern, with the QX9775 scoring 2363 versus 2350, a 0.6% margin. In Cinebench R23 single-core, the QX9775 leads 333 to 331, another 0.6% edge.

Across all five tests, the QX9775's average delta is roughly 0.5%, meaning the i7-870S is never more than a point or two behind in any given metric. The largest absolute gap is 13 points in Cinebench R23 multicore (2363 versus 2350), which is still under 1%. For context, the QX9775's nearest rival is the Intel Core i7-5550U with an identical average score of 813, while the i7-870S's nearest rival is the AMD A10-6800K at 809. Both chips sit at the 22nd percentile, placing them in the lower-middle range of all CPUs.

The Verdict

From the data alone, the Intel Core 2 Extreme QX9775 is the faster processor in every benchmark category, but the margins are so small that the choice between these two should hinge on other factors. The QX9775 wins all five head-to-head tests, yet its largest advantage is 0.8%, which is negligible in real-world use. If the priority is raw benchmark scores, the QX9775 is the pick — it leads in multicore and single-core Cinebench tests alike, and its unlocked multiplier offers overclocking headroom that the locked i7-870S lacks.

However, the i7-870S has compensating attributes that the benchmark scores do not capture. Its TDP is 82 watts versus 150 watts for the QX9775, a substantial difference that makes it far easier to cool and cheaper to run. It uses DDR3 memory with dual-channel support, whereas the QX9775 depends on DDR2 with motherboard-dependent support. The i7-870S also has 8 MB of shared L3 cache and 256 KB of L2 per core, which could benefit workloads not represented in these Cinebench tests, even though it does not help here.

For a user building a system today, the i7-870S's lower power draw and newer memory standard make it the more practical choice, despite losing every benchmark. For a user who wants the highest possible performance in Cinebench and has no concern for power or thermals, the QX9775 is the data-backed winner. Neither processor is competitive by modern standards — both sit at the 22nd percentile — so the decision is really about whether a sub-1% benchmark advantage justifies the QX9775's 150-watt TDP and DDR2 dependency.

FAQ

Q: Which processor wins more benchmarks?

A: The Intel Core 2 Extreme QX9775 wins all five head-to-head tests, with deltas ranging from 0% to 0.8%. The Intel Core i7-870S wins zero tests.

Q: How close are the two in single-core performance?

A: They are essentially tied. In Cinebench R20 single-core, both score exactly 139. In Cinebench R23 single-core, the QX9775 scores 333 versus 331 for the i7-870S, a 0.6% difference.

Q: What is the average benchmark score for each?

A: The QX9775 has an average benchmark score of 813, while the i7-870S averages 809. Both sit at the 22nd percentile among all CPUs.

Q: Does the i7-870S's higher thread count help in multicore tests?

A: No. Despite having 8 threads versus 4 on the QX9775, the i7-870S loses in every multicore test. For example, Cinebench R15 multicore shows 238 versus 236 in favor of the QX9775.

Q: What are the TDP differences between the two?

A: The QX9775 has a TDP of 150 watts, while the i7-870S has a TDP of 82 watts. This is a significant power draw difference that is not reflected in benchmark scores.

Q: Do both processors support ECC memory?

A: No. The QX9775 supports ECC memory, while the i7-870S does not. The i7-870S also uses DDR3, while the QX9775 uses DDR2 depending on the motherboard.

Specification Differences

| Specification | Intel Core 2 Extreme QX9775 | Intel Core i7-870S |

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

| Cores | 4 | 4 |

| Threads | 4 | 8 |

| Base Clock | 3.20 GHz | 2.67 GHz |

| Boost Clock | None | 3.60 GHz |

| TDP | 150 W | 82 W |

| Socket | Intel Socket 771 | Intel Socket 1156 |

| Architecture | Core 2 | Nehalem |

| Codename | Yorkfield | Lynnfield |

| Transistors | 820 million | 774 million |

| Die Size | 2x 107 mm² | 296 mm² |

| L2 Cache | 6 MB (per die) | 256 KB (per core) |

| L3 Cache | None | 8 MB (shared) |

| Memory Support | DDR2 (depends on motherboard) | DDR3 |

| Memory Bus | Not specified | Dual-channel |

| ECC Memory | Yes | No |

| PCIe | Gen 1 | Gen 2, 16 Lanes (CPU only) |

| Multiplier Unlocked | Yes | No |

| Release Date | 2008-03-23 | 2010-07-18 |

| Launch MSRP | $1499 | Not specified |

| Part Number | SLANYEU80574XL088N | SLBQ7 |