Intel Core i7-2820QM vs Intel Xeon W3580 Comparison

The Intel Core i7-2820QM and the Intel Xeon W3580 are both 4-core, 8-thread processors from Intel, but they target entirely different eras and market segments. The benchmark data is clear: the mobile i7-2820QM wins every single head-to-head test, despite the Xeon’s higher clock speeds. The i7-2820QM holds a consistent lead of roughly 19.6% to 19.7% across all Cinebench workloads, making it the better performer in every measurable way. This is a decisive victory for the newer Sandy Bridge architecture, even though the Xeon W3580 was designed as a high-end workstation part. The data shows no scenario where the Xeon pulls ahead, so the choice between them is straightforward for raw compute performance.

Head-to-Head Benchmarks

The most striking pattern in this comparison is the uniformity of the i7-2820QM’s advantage. In Cinebench R15 multi-core, the i7-2820QM scores 372 against the Xeon W3580’s 311, a 19.6% margin. That same 19.6% delta repeats in Cinebench R20 multi-core, where the i7-2820QM hits 1552 versus 1298. The single-core tests tell the same story: Cinebench R20 single-core shows the i7-2820QM at 219 and the Xeon at 183, a 19.7% lead. Cinebench R23 multi-core continues the trend, with the i7-2820QM at 3697 and the Xeon at 3092, again a 19.6% gap. In Cinebench R23 single-core, the i7-2820QM scores 522 against 436, another 19.7% win.

The consistency of these deltas is notable. It suggests the performance difference is not workload-specific but rather a fundamental architectural advantage. The Xeon W3580’s higher base clock of 3.33 GHz and boost clock of 3.60 GHz do not translate into better scores. The i7-2820QM, with a 2.30 GHz base and 3.40 GHz boost, outperforms it in every test by a nearly identical percentage. This points to instructions-per-clock (IPC) improvements in Sandy Bridge being the deciding factor, rather than raw clock speed. The data shows no benchmark where the Xeon W3580 even comes close to matching the i7-2820QM, making this a one-sided contest from start to finish.

Architecture Differences

The two processors represent different generations of Intel silicon. The i7-2820QM uses the Sandy Bridge architecture on a 32 nm process node, while the Xeon W3580 is built on Nehalem (Bloomfield) using a 45 nm process. This process shrink is a major factor in the performance gap. The i7-2820QM packs 1,160 million transistors onto a 216 mm² die, whereas the Xeon W3580 has only 731 million transistors on a larger 263 mm² die. The newer process allows Sandy Bridge to integrate more functionality and improve efficiency.

Cache configurations are identical in capacity: both have 64 KB L1 per core, 256 KB L2 per core, and 8 MB of shared L3. However, the architectural implementation differs significantly. The i7-2820QM benefits from Sandy Bridge’s improved memory controller and execution engine. The Xeon W3580’s Nehalem architecture was groundbreaking in its day but lacks the refinements of the newer design.

Memory support also diverges. The i7-2820QM uses a dual-channel memory bus, while the Xeon W3580 supports triple-channel DDR3 memory. The Xeon also supports ECC memory, a feature the i7-2820QM lacks. The i7-2820QM includes integrated Intel HD 3000 graphics, while the Xeon W3580 has none. The Xeon uses PCIe Gen 2 and the older Intel Socket 1366, whereas the i7-2820QM uses Intel Socket G2 (988B). The i7-2820QM is a mobile part with a 45 W TDP; the Xeon W3580 is a server/workstation chip with a 130 W TDP.

Where Each One Wins

The i7-2820QM wins every benchmark in the dataset, so the use-case split is based on its superiority across the board. In multi-threaded workloads like Cinebench R15, R20, and R23, the i7-2820QM’s 19.6% lead makes it the clear choice for rendering, video encoding, or any heavily threaded task. The single-core results, with a 19.7% advantage, mean the i7-2820QM also handles older or lightly threaded applications better. The data indicates no scenario where the Xeon W3580 is preferable on performance grounds.

The Xeon W3580’s only potential advantages lie outside raw compute. It supports ECC memory, which is critical for mission-critical servers where data corruption is unacceptable. It also uses a triple-channel memory bus, which could offer higher memory bandwidth in theory, though the benchmark data does not reflect any real-world benefit in the tested workloads. The Xeon’s server segment classification means it might be compatible with workstation platforms that require ECC, but the i7-2820QM’s integrated graphics and lower power draw make it a more versatile mobile solution.

For a builder prioritizing raw performance, the i7-2820QM is the unequivocal winner. For someone building a server with ECC requirements, the Xeon W3580 has a niche role, but it will still be slower in CPU-bound tasks. The data shows the i7-2820QM is the better performer in every measured test, so the only reason to pick the Xeon is for platform-specific features like ECC or triple-channel memory configurations.

Specification Differences

• Base Clock: The i7-2820QM runs at 2.30 GHz, while the Xeon W3580 runs at 3.33 GHz.
• Boost Clock: The i7-2820QM boosts to 3.40 GHz; the Xeon W3580 boosts to 3.60 GHz.
• TDP: The i7-2820QM has a 45 W TDP; the Xeon W3580 has a 130 W TDP.
• Socket: The i7-2820QM uses Intel Socket G2 (988B); the Xeon W3580 uses Intel Socket 1366.
• Architecture: The i7-2820QM is Sandy Bridge; the Xeon W3580 is Nehalem (Bloomfield).
• Process Node: The i7-2820QM uses 32 nm; the Xeon W3580 uses 45 nm.
• Transistors: The i7-2820QM has 1,160 million; the Xeon W3580 has 731 million.
• Die Size: The i7-2820QM is 216 mm²; the Xeon W3580 is 263 mm².
• Memory Bus: The i7-2820QM is dual-channel; the Xeon W3580 is triple-channel.
• ECC Memory: The i7-2820QM does not support it; the Xeon W3580 does.
• Integrated Graphics: The i7-2820QM includes Intel HD 3000; the Xeon W3580 has none.
• Market Segment: The i7-2820QM is Mobile; the Xeon W3580 is Server/Workstation.
• Release Date: The i7-2820QM released on 2011-01-02; the Xeon W3580 released on 2009-08-08.
• Part Number: The i7-2820QM is SR012; the Xeon W3580 is SLBET.

FAQ

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

A: The Intel Core i7-2820QM wins all multi-core tests. In Cinebench R23 multi-core, it scores 3697 versus 3092 for the Xeon W3580, a 19.6% advantage. The same margin applies to Cinebench R15 multi-core (372 vs 311) and Cinebench R20 multi-core (1552 vs 1298).

Q: Does the Xeon W3580’s higher clock speed help it win any tests?

A: No. Despite having a higher base clock (3.33 GHz vs 2.30 GHz) and boost clock (3.60 GHz vs 3.40 GHz), the Xeon W3580 loses every benchmark. The i7-2820QM’s architectural efficiency overcomes the clock deficit.

Q: Which CPU supports ECC memory?

A: Only the Intel Xeon W3580 supports ECC memory. The Intel Core i7-2820QM does not have ECC support. This is a key differentiator for server use cases where data integrity is critical.

Q: How do their power requirements compare?

A: The i7-2820QM has a TDP of 45 W, while the Xeon W3580 has a TDP of 130 W. The i7-2820QM is far more power-efficient, which is expected given its mobile market segment.

Q: What are the L3 cache sizes for both processors?

A: Both processors have 8 MB of shared L3 cache. They also share identical L1 (64 KB per core) and L2 (256 KB per core) cache configurations. The performance difference comes from architecture, not cache capacity.

Q: Are there any benchmarks where the Xeon W3580 wins?

A: In the provided head-to-head data, the Xeon W3580 wins zero tests. The i7-2820QM wins all five benchmarks, covering Cinebench R15, R20, and R23 in both single-core and multi-core modes.

The Verdict

The data is unambiguous: the Intel Core i7-2820QM is the superior processor in every measured benchmark. It outperforms the Xeon W3580 by a consistent 19.6% to 19.7% across all Cinebench tests, despite having lower clock speeds. The i7-2820QM’s Sandy Bridge architecture on a 32 nm process delivers higher instructions-per-clock than the Xeon’s older Nehalem design on 45 nm. This architectural advantage is so significant that no amount of clock speed from the Xeon can compensate.

The i7-2820QM is the right choice for anyone prioritizing raw compute performance. It wins multi-core workloads like rendering and video encoding by nearly 20%, and it wins single-core tasks by the same margin. It also consumes far less power, with a 45 W TDP versus the Xeon’s 130 W TDP, and includes integrated graphics for added functionality. The Xeon W3580’s only redeeming features are ECC memory support and a triple-channel memory bus, which are platform-specific benefits that do not translate into better benchmark scores.

For a general-purpose build or a mobile workstation, the i7-2820QM is the clear pick. For a server requiring ECC memory and a triple-channel memory topology, the Xeon W3580 has a niche role, but it will still be slower in CPU-bound tasks. The verdict from the data is simple: choose the i7-2820QM for performance, and only consider the Xeon W3580 if you absolutely need ECC memory support. Both are end-of-life products, but the i7-2820QM remains the better performer of the two.