Intel Core i7-3720QM vs Intel Core i7-3820 Comparison

The Intel Core i7-3820 and Intel Core i7-3720QM are both 4-core, 8-thread processors from 2012, but they target entirely different platforms. The i7-3820 is a desktop part built on the Sandy Bridge-E architecture, while the i7-3720QM is a mobile chip using Ivy Bridge. Despite the i7-3820’s higher power draw and older architecture, benchmark data shows it consistently outperforms the mobile part across all tested workloads, with a 4.3% to 4.5% advantage in every Cinebench test. However, the i7-3720QM brings a newer manufacturing process, a smaller die, and integrated graphics, making it a more efficient and self-contained option for laptops.

FAQ

Q: Which processor has a higher average benchmark score?

A: The Intel Core i7-3820 has an average benchmark score of 1424, while the Intel Core i7-3720QM scores 1421. The difference is minimal, at 0.2% in favor of the desktop chip.

Q: How do the two chips compare in terms of power consumption?

A: The i7-3820 has a TDP of 130 watts, whereas the i7-3720QM has a much lower TDP of 45 watts. This makes the mobile processor significantly more power-efficient, a critical factor for laptop use.

Q: What is the difference in their L3 cache sizes?

A: The i7-3820 features 10 MB of shared L3 cache, while the i7-3720QM has 6 MB of shared L3 cache. The desktop part’s larger cache likely contributes to its performance lead.

Q: Do both processors have integrated graphics?

A: No. The i7-3720QM includes Intel HD 4000 integrated graphics, while the i7-3820 has no integrated graphics. This means the desktop chip requires a discrete graphics card to output video.

Q: Which processor has a higher boost clock speed?

A: The i7-3820 has a boost clock of 3.80 GHz, compared to the i7-3720QM’s boost clock of 3.60 GHz. The i7-3820 also has a higher base clock of 3.60 GHz versus 2.60 GHz on the mobile chip.

Q: How does the i7-3820 perform against the i7-3720QM in the Cinebench R23 multi-core test?

A: The i7-3820 scores 4923, while the i7-3720QM scores 4718. This gives the i7-3820 a 4.3% lead in this particular test.

Where Each One Wins

The benchmark data paints a very clear picture: the Intel Core i7-3820 wins every single head-to-head benchmark. Across all six Cinebench tests, it holds a consistent lead ranging from 4.3% to 4.5%. This makes it the definitive choice for raw computational performance, whether in single-core or multi-core workloads. For desktop users who prioritize maximum processing power for tasks like video rendering, 3D modeling, or heavy multitasking, the i7-3820 is the superior option.

The Intel Core i7-3720QM, while losing every benchmark, wins in the context of its platform. As a mobile processor, its 45-watt TDP is a fraction of the i7-3820’s 130-watt TDP. This efficiency, combined with its integrated Intel HD 4000 graphics, makes it the only viable choice for a laptop or other portable system where power draw and space are at a premium. The data shows it is not about winning on performance, but about delivering a usable level of performance within the constraints of a mobile chassis.

Architecture Differences

The two processors are built on different Intel architectures and manufacturing processes. The i7-3820 uses the Sandy Bridge architecture, specifically the Sandy Bridge-E variant, built on a 32 nm process node. It packs 1,270 million transistors onto a large 294 mm² die. In contrast, the i7-3720QM uses the newer Ivy Bridge architecture on a more advanced 22 nm process. This allows Intel to fit 1,400 million transistors onto a much smaller 160 mm² die. This architectural shift brings efficiency gains, evidenced by the mobile chip’s dramatically lower TDP.

Memory support also differs significantly. The i7-3820 supports quad-channel DDR3 memory with a theoretical bandwidth of 51.2 GB/s. The i7-3720QM, on the other hand, uses dual-channel memory, with no bandwidth figure provided in the data. This memory bandwidth advantage for the desktop part is another factor in its higher performance. Additionally, the i7-3820 offers 40 PCIe Gen 2 lanes from the CPU, a feature not listed for the mobile chip, catering to high-end desktop expansion needs.

Specification Differences

The most striking difference is the TDP: 130 watts for the i7-3820 versus 45 watts for the i7-3720QM. Clock speeds also differ, with the i7-3820 having a base clock of 3.60 GHz and a boost clock of 3.80 GHz, while the i7-3720QM runs at 2.60 GHz base and 3.60 GHz boost. The i7-3820 uses the Intel Socket 2011, while the i7-3720QM is soldered onto Intel BGA 1224, reflecting their desktop and mobile roles respectively.

Cache configuration is another differentiator: the i7-3820 has 10 MB of shared L3 cache, while the i7-3720QM has 6 MB. The i7-3820 supports quad-channel memory, while the i7-3720QM uses dual-channel. The i7-3820 has no integrated graphics, but the i7-3720QM includes Intel HD 4000. The i7-3820 also has an unlocked multiplier, allowing for overclocking, whereas the i7-3720QM’s multiplier is locked. The i7-3820 has a launch MSRP of $305; no launch MSRP is listed for the mobile part.

Head-to-Head Benchmarks

The Cinebench results are remarkably consistent, showing a uniform performance gap. In Cinebench R15 multi-core, the i7-3820 scores 496 against the i7-3720QM’s 475, a 4.4% lead. The single-core test shows a similar story: 69 versus 66, a 4.5% advantage. Moving to Cinebench R20, the i7-3820 again wins multi-core with 2067 points over 1981, a 4.3% margin, and single-core with 291 over 279, also a 4.3% margin.

The trend continues in Cinebench R23. In the multi-core test, the i7-3820 scores 4923, while the i7-3720QM scores 4718, a 4.3% lead. The single-core test yields 695 for the i7-3820 and 666 for the i7-3720QM, a 4.4% advantage. The data shows no test where the mobile chip closes the gap; the desktop processor’s higher clock speeds and larger cache consistently deliver a decisive, if modest, victory across all workloads.

The Verdict

For users building a desktop workstation, the Intel Core i7-3820 is the clear pick. Its performance is superior in every measured benchmark, with a 4.3% to 4.5% lead over the i7-3720QM in both single-core and multi-core tasks. Its support for quad-channel memory and 40 PCIe Gen 2 lanes makes it a more robust platform for heavy workloads. The unlocked multiplier is a bonus for enthusiasts who want to push performance further. The data shows no scenario where the mobile chip outperforms the desktop part.

For laptop users, the choice is equally clear: the Intel Core i7-3720QM is the only sensible option. While it loses every performance comparison, it does so while consuming only 45 watts, less than a third of the i7-3820’s 130-watt TDP. Its integrated Intel HD 4000 graphics eliminate the need for a separate GPU, saving space and power. The data shows that the i7-3720QM’s value lies not in raw speed, but in providing capable multi-threaded performance in a power-efficient, mobile-friendly package. It is the right tool for a portable system, while the i7-3820 is the right tool for a high-performance desktop.