Intel Core 2 Extreme QX9775 vs Intel Xeon X3440 Comparison

The Intel Xeon X3440 and Intel Core 2 Extreme QX9775 are separated by a generation of architecture, yet their benchmark results are remarkably close. The data shows the Xeon X3440 edges out the Core 2 Extreme in every single head-to-head test, though the margins are often razor-thin. The Xeon’s victory confirms the efficiency of its newer Nehalem design, which compensates for a lower clock speed with simultaneous multithreading and a more modern memory controller.

Head-to-Head Benchmarks

The benchmark results paint a picture of near-parity, but with a consistent, if narrow, advantage for the Xeon X3440. Across all five Cinebench tests, the Xeon X3440 wins, but the largest margin is a mere 0.7% in the Cinebench R20 single-core test. That test shows the Xeon scoring 140 against the Core 2 Extreme’s 139. This is a negligible difference for single-threaded workloads, indicating that the Core 2 Extreme’s higher 3.20 GHz base clock nearly neutralizes the architectural advantages of the Xeon in this specific scenario.

In multi-core workloads, the story is similar. In Cinebench R15 multi-core, both processors score an identical 238 points, with the Xeon X3440 declared the winner with a delta of 0%. The Xeon’s 8 threads (versus the Core 2 Extreme’s 4) and 8 MB of shared L3 cache should theoretically provide a significant advantage here, but the data shows the older Yorkfield part holds its ground. Moving to the more demanding Cinebench R20 multi-core test, the Xeon X3440 scores 994, just 2 points ahead of the 992 from the Core 2 Extreme QX9775, a delta of 0.2%. The pattern continues in Cinebench R23 multi-core, where the Xeon scores 2368 versus 2363, another 0.2% delta.

The overall average benchmark score confirms this trend. The Xeon X3440 has an average benchmark score of 815, while the Core 2 Extreme sits at 813. According to the nearestRivals data, the Xeon is 0.2% ahead of the Core 2 Extreme, while the Core 2 Extreme’s own data shows it is 0.2% behind the Xeon. The single-core R20 and R23 results (140 vs 139 and 334 vs 333, respectively) show the Xeon with 0.7% and 0.3% leads. This data suggests that in real-world applications, users would be hard-pressed to feel any difference in performance between these two CPUs, despite their different designs and market positions.

Architecture Differences

The fundamental difference lies in the microarchitecture. The Xeon X3440 is based on the Nehalem architecture (codenamed Lynnfield), while the Core 2 Extreme QX9775 uses the older Core 2 architecture (codenamed Yorkfield). Both are built on Intel’s 45 nm process node, but the transistor counts differ. The Xeon packs 774 million transistors on a 296 mm² die, while the Core 2 Extreme has 820 million transistors spread across two dies, each measuring 107 mm². This dual-die design for the Core 2 Extreme is a key physical difference, as it requires a more complex communication path between the two dies.

The most consequential architectural difference is in threading. The Xeon X3440 supports 8 threads via Hyper-Threading, while the Core 2 Extreme QX9775 is a pure 4-core, 4-thread part. This allows the Xeon to better utilize its execution resources in heavily threaded workloads, which is why it manages to match or slightly beat the Core 2 Extreme despite a lower base clock of 2.53 GHz versus 3.20 GHz. The Xeon also has a boost clock of 2.93 GHz, a feature entirely absent from the Core 2 Extreme, which runs at a fixed 3.20 GHz.

Cache configurations also differ significantly. The Xeon X3440 has a modern three-tier cache hierarchy: 64 KB of L1 per core, 256 KB of L2 per core, and a large 8 MB shared L3 cache. The Core 2 Extreme, lacking an L3 cache, relies on a larger L2 cache of 6 MB per die. This means the Xeon’s shared L3 cache is more efficient for data sharing between cores, while the Core 2 Extreme’s L2 cache is physically attached to each die, making inter-die communication slower. Memory support also diverges. The Xeon supports DDR3 memory on a dual-channel bus with a theoretical bandwidth of 21.3 GB/s. The Core 2 Extreme supports DDR2, with the exact speed depending on the motherboard, and has no listed memory bandwidth figure in the data.

Other key differences include the socket (Intel Socket 1156 for the Xeon versus Intel Socket 771 for the Core 2 Extreme), PCIe generation (Gen 2 with 16 lanes for the Xeon versus Gen 1 for the Core 2 Extreme), and TDP. The Xeon is rated at 95W, while the Core 2 Extreme draws significantly more power at 150W. The Core 2 Extreme has an unlocked multiplier, making it more flexible for overclocking, while the Xeon’s multiplier is locked. The Xeon is also a Server/Workstation part, while the Core 2 Extreme is a Desktop part.

FAQ

Q: Which processor is faster in multi-core benchmarks?

A: The Intel Xeon X3440 wins all multi-core tests, but by a minimal margin. In Cinebench R20 multi-core, it scores 994 versus 992 for the Core 2 Extreme QX9775, and in Cinebench R23 multi-core, it scores 2368 versus 2363. The delta is consistently 0.2% in favor of the Xeon.

Q: Is the Core 2 Extreme QX9775 better for single-core tasks due to its higher clock speed?

A: No, the data does not support this. Despite having a 3.20 GHz base clock versus the Xeon’s 2.53 GHz, the Core 2 Extreme loses in the single-core tests. In Cinebench R20 single-core, it scores 139 against the Xeon’s 140, and in R23 single-core, it scores 333 versus 334.

Q: Does the Xeon X3440 have more processing threads?

A: Yes, the Xeon X3440 supports 8 threads, while the Core 2 Extreme QX9775 supports only 4 threads. This is a fundamental architectural difference, as the Xeon uses Hyper-Threading to process two threads per core.

Q: What are the major differences in cache memory?

A: The Xeon X3440 has a three-tier cache: 64 KB of L1 per core, 256 KB of L2 per core, and 8 MB of shared L3 cache. The Core 2 Extreme QX9775 has 64 KB of L1 per core and 6 MB of L2 per die, but it has no L3 cache.

Q: Are these processors from the same generation?

A: No. The Xeon X3440 is based on the Nehalem architecture and was released later, while the Core 2 Extreme QX9775 uses the older Core 2 architecture. The release dates confirm this, though specific dates are not the focus of this analysis.

Q: Which processor has a higher average benchmark score?

A: The Intel Xeon X3440 has a slightly higher average benchmark score of 815, compared to 813 for the Intel Core 2 Extreme QX9775. This is a 0.2% difference, placing them in the same performance tier, as both have a percentile rank of 22 versus all CPUs.

The Verdict

Based strictly on the benchmark data, the Intel Xeon X3440 is the superior processor. It wins all five head-to-head benchmarks, albeit by very small margins. Its average benchmark score of 815 is higher than the 813 of the Core 2 Extreme QX9775. The Xeon achieves this with a significantly lower TDP of 95W versus 150W, making it a more power-efficient choice. The Xeon also supports newer technologies, including DDR3 memory, PCIe Gen 2, and a modern memory bus with a listed bandwidth of 21.3 GB/s.

However, the performance gap is so small that it is practically irrelevant for most workloads. The Core 2 Extreme QX9775, with its higher base clock and unlocked multiplier, offers a compelling alternative for users who prioritize overclocking flexibility. The decision comes down to the platform. The Xeon X3440, with its server/workstation market segment, is designed for stability and multi-threaded throughput. The Core 2 Extreme, as a desktop part, might be more familiar to enthusiasts of that era. For anyone building a system today, the Xeon X3440 is the better choice based on its benchmark wins, lower power draw, and more modern feature set. The Core 2 Extreme’s sole advantages are its unlocked multiplier and its dual-die design, which does not translate to a performance win in this data.

Specification Differences

The following table highlights only the specifications where the two processors differ, as per the data:

| Specification | Intel Xeon X3440 | Intel Core 2 Extreme QX9775 |

|:--- |:--- |:--- |

| Threads | 8 | 4 |

| Base Clock | 2.53 GHz | 3.20 GHz |

| Boost Clock | 2.93 GHz | None |

| TDP | 95 W | 150 W |

| Socket | Intel Socket 1156 | Intel Socket 771 |

| Architecture | Nehalem | Core 2 |

| Codename | Lynnfield | Yorkfield |

| Transistors | 774 million | 820 million |

| Die Size | 296 mm² | 2x 107 mm² |

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

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

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

| Memory Bus | Dual-channel | Not specified |

| Memory Bandwidth | 21.3 GB/s | Not specified |

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

| Market Segment | Server/Workstation | Desktop |

| Launch MSRP | $215 | $1499 |

| Multiplier Unlocked | No | Yes |

| Part Number | SLBLF | SLANYEU80574XL088N |

Where Each One Wins

The benchmark data grants the Intel Xeon X3440 a clean sweep, but the margins dictate different use cases. The Xeon X3440 wins in all measured scenarios, including multi-core and single-core tests. Its victory in the Cinebench R15 multi-core test, where both score 238, is nominal. However, its consistent wins in the R20 and R23 tests, while small, indicate that its Hyper-Threading and shared L3 cache provide a slight edge in heavily threaded applications like modern video encoding or 3D rendering. The Xeon also wins on efficiency, with a 95W TDP, making it suitable for dense server environments where power draw matters.

The Intel Core 2 Extreme QX9775, despite losing all benchmark comparisons, still has a defined role. Its 3.20 GHz base clock is higher than both the Xeon’s base and boost clocks, and its unlocked multiplier makes it the clear choice for enthusiasts seeking to push clock speeds manually. In a scenario where a user is willing to overclock heavily, the Core 2 Extreme could potentially close the small performance gap, although this is not reflected in the stock benchmark data. For legacy applications that are highly sensitive to raw clock speed and do not efficiently use more than four threads, the Core 2 Extreme’s higher clock speed is its only theoretical advantage, as even in single-core tests, it fails to beat the Xeon. Thus, the Xeon X3440 is the default pick for any workload requiring maximum stock performance or power efficiency, while the Core 2 Extreme is for those who value the overclocking headroom provided by its unlocked multiplier.