Intel Core i7-2700K vs Intel Core i7-3720QM Comparison

The Intel Core i7-3720QM and Intel Core i7-2700K are both 4-core, 8-thread processors from Intel, but they represent fundamentally different design philosophies: one is a mobile chip built for efficiency, the other a desktop chip built for raw frequency. Despite their differences in age and target platform, the benchmark data places them in a near-identical performance class, with an average benchmark score of 1421 for the mobile part and 1419 for the desktop part. The head-to-head results reveal a fascinating split, where the older desktop chip wins the majority of Cinebench tests, but the newer mobile chip dominates in Geekbench.

Head-to-Head Benchmarks

The most striking outcome of the head-to-head comparison is that the Intel Core i7-2700K wins six of the eight benchmark tests, yet the overall average scores are nearly tied. In the Cinebench suite, the desktop chip consistently outperforms the mobile chip by a narrow margin. In Cinebench R15 multi-core, the 2700K scores 486 against the 3720QM's 475, a delta of -2.3%. The single-core test shows the same pattern, with the 2700K at 68 points versus 66 points for the 3720QM, a -2.9% difference. This trend continues through the R20 and R23 versions of the test. In Cinebench R20 multi-core, the scores are 2029 for the 2700K and 1981 for the 3720QM (-2.4%), and in R23 multi-core, the 2700K posts 4833 against the 3720QM's 4718, again a -2.4% delta. The single-core results in these newer versions are also consistent, with the 2700K winning by -2.4% in R20 (286 vs 279) and -2.3% in R23 (682 vs 666). The data suggests that in Cinebench's rendering workloads, the higher clock speeds of the desktop chip provide a consistent, albeit small, advantage.

However, the story flips completely in the Geekbench tests. Here, the Intel Core i7-3720QM takes a decisive lead. In Geekbench multi-core, the mobile chip scores 2457 compared to the 2700K's 2294, a substantial 7.1% advantage. The single-core result is even more pronounced, with the 3720QM scoring 726 versus the 2700K's 672, an 8% delta. This is a significant swing. The 3720QM wins by roughly 7-8% in Geekbench, while losing by only 2-3% in Cinebench. This divergence points to architectural efficiency differences that manifest differently depending on the workload. The data implies that the newer Ivy Bridge architecture, despite a lower clock speed, is more efficient at executing the types of instructions used in Geekbench, while the older Sandy Bridge design with its higher clocks holds the edge in Cinebench's specific rendering tasks.

Architecture Differences

The fundamental architectural divide between these two processors is the manufacturing process and the microarchitecture itself. The Intel Core i7-3720QM is built on the Ivy Bridge architecture using a 22 nm process node, while the Intel Core i7-2700K uses the Sandy Bridge architecture on a 32 nm process node. This process shrink has a direct impact on the physical characteristics of the chips. The 3720QM contains 1,400 million transistors on a die size of 160 mm², whereas the 2700K packs 1,160 million transistors onto a larger 216 mm² die. This means the mobile chip fits more transistors into a smaller physical area, which is a key factor in its dramatically lower power consumption.

The cache hierarchy also differs between the two. Both chips share the same L1 cache configuration at 64 KB per core and L2 cache at 256 KB per core. The difference lies in the L3 cache: the 3720QM has 6 MB of shared L3 cache, while the 2700K has a larger 8 MB shared L3 cache. This 2 MB difference could partially explain the 2700K's advantage in Cinebench, as the larger cache can hold more working data for the rendering engine, reducing the need to access slower main memory. The integrated graphics also differ, with the 3720QM featuring Intel HD 4000 and the 2700K featuring Intel HD 3000. Other notable differences include the memory bus, which is dual-channel for both, but the 2700K lists a specific memory bandwidth of 21.3 GB/s and DDR3 memory support, while the 3720QM's memory support is not specified in the data.

Where Each One Wins

The benchmark results paint a clear picture of workload-specific strengths. The Intel Core i7-2700K is the winner in rendering and compute-heavy tasks that are similar to Cinebench's workloads. Its six wins in the Cinebench suite, spanning R15, R20, and R23, indicate that applications which rely on sustained multi-threaded CPU performance and are sensitive to cache size will favor this chip. The 8 MB L3 cache and higher base and boost clocks (3.50 GHz and 3.90 GHz) provide a tangible benefit in these scenarios. For users running 3D rendering, video encoding, or other long-duration compute tasks, the data suggests the 2700K holds a slight but consistent edge, typically around 2-3%.

Conversely, the Intel Core i7-3720QM wins decisively in the Geekbench tests, which are often more representative of general-purpose computing, including tasks like image processing, encryption, and physics simulations. The 7.1% and 8% advantages in multi-core and single-core Geekbench scores, respectively, are much larger than the 2700K's Cinebench lead. This suggests that for everyday application performance, web browsing, office work, and other tasks that are not purely rendering-based, the 3720QM is the more capable processor. The data indicates that the architectural improvements in Ivy Bridge, such as better instruction handling and memory management, provide a significant boost in these types of workloads, overcoming the clock speed deficit (2.60 GHz base and 3.60 GHz boost for the 3720QM).

Specification Differences

The specification sheets for these two processors show a clear divergence in their intended use cases. The most obvious difference is the thermal design power (TDP), with the 3720QM rated at a mere 45 watts compared to the 2700K's 95 watts. This highlights the mobile nature of the 3720QM, designed to fit into laptops with limited cooling and battery constraints. The socket types also differ, with the 3720QM using an Intel BGA 1224 (a soldered mobile socket) and the 2700K using the desktop Intel Socket 1155. This means the 3720QM is not upgradeable in the traditional sense, while the 2700K can be replaced by the user.

The market segments are explicitly different: the 3720QM is a Mobile part, while the 2700K is a Desktop part. The production status also varies, with the 2700K listed as "End-of-life" while the 3720QM has no such status listed. A key feature difference is the multiplier lock. The 3720QM has a locked multiplier, meaning its clock speed cannot be easily overclocked. In contrast, the 2700K has an unlocked multiplier, which is a hallmark of Intel's "K" series processors, specifically designed for enthusiast overclocking. The release dates show the 2700K was released on 2011-10-23, while the 3720QM came later on 2012-04-28. The 2700K's part number is SR0DG, and it has a listed launch MSRP of $332, whereas the 3720QM's part number is SR0MM with no launch MSRP provided.

FAQ

Q: Which processor has a higher average benchmark score?

A: The Intel Core i7-3720QM has a marginally higher average benchmark score of 1421, compared to the Intel Core i7-2700K's 1419. This is a difference of only 0.2% based on the nearestRivals deltaPct data.

Q: Why does the Core i7-2700K win most of the Cinebench tests?

A: The data shows the 2700K wins all six Cinebench tests (R15, R20, R23, both multi-core and single-core) by margins of 2.3% to 2.9%. This is likely due to its higher base clock of 3.50 GHz and boost clock of 3.90 GHz, as well as its larger 8 MB shared L3 cache, which can benefit rendering workloads.

Q: How much faster is the Core i7-3720QM in Geekbench?

A: The 3720QM is significantly faster in Geekbench. It scores 8% higher in the single-core test (726 vs 672) and 7.1% higher in the multi-core test (2457 vs 2294) compared to the 2700K.

Q: Can either of these processors be overclocked?

A: Only the Intel Core i7-2700K has an unlocked multiplier, which allows for overclocking. The Intel Core i7-3720QM has a locked multiplier, preventing this type of performance tuning.

Q: What is the difference in power consumption between the two?

A: The Intel Core i7-3720QM has a TDP of 45 watts, while the Intel Core i7-2700K has a TDP of 95 watts. This makes the mobile chip over 50% more power-efficient on paper.

Q: Which processor has more L3 cache?

A: The Intel Core i7-2700K has more L3 cache, with 8 MB shared, compared to the 6 MB shared on the Intel Core i7-3720QM. Both have identical L1 (64 KB per core) and L2 (256 KB per core) cache configurations.

The Verdict

The data presents a classic trade-off between power efficiency and raw clock speed. The Intel Core i7-2700K is the clear winner for users who prioritize rendering performance and have the ability and desire to overclock, given its unlocked multiplier. Its consistent 2-3% lead across all Cinebench versions makes it the better choice for video editors and 3D artists using software that scales with cache and clock frequency. Its "End-of-life" status, however, suggests it is an older platform.

The Intel Core i7-3720QM, on the other hand, is the superior choice for general-purpose computing and mobile use. Its 45-watt TDP makes it suitable for laptops, and its substantial 7-8% lead in Geekbench indicates it handles everyday tasks, web browsing, and productivity applications more efficiently. The architectural improvements of the 22 nm Ivy Bridge process appear to give it a real-world performance advantage in non-rendering workloads, despite its lower clock speeds. For anyone looking at a mobile platform or prioritizing overall system responsiveness over pure render times, the 3720QM is the better performer. The 2700K is the pick for desktop overclockers and render-focused tasks, while the 3720QM is the pick for efficiency and general application speed.