Intel Core i7-2600K vs Intel Core i7-3840QM Comparison

The Verdict

The Intel Core i7-2600K and the Intel Core i7-3840QM occupy the same overall performance percentile (37th) in the database, meaning both sit at an identical position relative to all other recorded CPUs. However, the benchmark split is decisive: the 3840QM claims 6 wins, while the 2600K takes only 2 wins, and the nature of those victories points to very different workloads. The i7-3840QM is the stronger choice for sustained rendering workloads, leading in every Cinebench test across R15, R20, and R23 in both single-core and multicore runs. The i7-2600K counters with a commanding lead in Geekbench, but its wins there (23.8% and 22.3%) do not outweigh the consistency of the mobile chip in the Cinebench suite. For users prioritizing Cinebench-style multithreaded tasks, the 3840QM is the clear pick. The 2600K remains preferable only where Geekbench scores dominate the selection criteria.

Architecture Differences

The two processors come from different Intel microarchitectures and process nodes. The i7-2600K is a Sandy Bridge design built on Intel's 32 nm process, while the i7-3840QM is an Ivy Bridge part built on 22 nm. This node change brings a different transistor count: the 2600K packs 1,160 million transistors on a 216 mm² die, whereas the 3840QM has 1,400 million transistors on a smaller 160 mm² die. Both use the same per-core cache layout of 64 KB L1 and 256 KB L2, and both share 8 MB of L3 cache. The integrated graphics differ, with the 2600K featuring Intel HD 3000 and the 3840QM featuring Intel HD 4000. The 2600K is a desktop part on Intel Socket 1155 with a 95 W TDP, while the 3840QM is a mobile part on Intel BGA 1224 with a 45 W TDP. The 2600K has an unlocked multiplier, the 3840QM does not. The 2600K supports DDR3 memory with dual-channel bus and 25.6 GB/s bandwidth, while the 3840QM also supports DDR3 dual-channel, but its memory bandwidth is not recorded in the database. The 2600K lists PCIe Gen 2 with 16 lanes (CPU only); the 3840QM has no recorded PCIe field. The 2600K's launch MSRP was $317, whereas the 3840QM has no recorded launch price. The 2600K is marked end-of-life, with a release date in early 2011, while the 3840QM has no production status recorded and a release date in late 2012.

FAQ

Q: Which processor has the higher base clock?

A: The i7-2600K has a base clock of 3.40 GHz, while the i7-3840QM has a base clock of 2.80 GHz. Both share the same boost clock of 3.80 GHz.

Q: How do the two compare in Geekbench multicore scores?

A: The i7-2600K scores 2613 in Geekbench multicore, which is 23.8% ahead of the i7-3840QM's 2111 score. The 2600K also leads single-core Geekbench with 768 versus 628, a 22.3% advantage.

Q: Which chip wins in Cinebench R23 multicore?

A: The i7-3840QM scores 4952 in Cinebench R23 multicore compared to the i7-2600K's 4657, a 6% margin in favor of the mobile chip.

Q: Do both processors have the same core and thread counts?

A: Yes, both are 4-core, 8-thread processors. They also share the same L3 cache size of 8 MB shared.

Q: Are there differences in power consumption?

A: Yes. The i7-2600K has a TDP of 95 W, while the i7-3840QM is rated at 45 W, a substantially lower envelope for the mobile chip.

Q: Which processor has a higher average benchmark score?

A: The i7-2600K has an average benchmark score of 1433, while the i7-3840QM averages 1416. The 2600K's nearest rival, the Intel Core i7-4712HQ, scores 1436 with a delta of -0.2%, while the 3840QM's nearest rival, the AMD Ryzen 7 2700U, scores 1415 with a delta of 0.1%.

Specification Differences

The two processors differ across nearly every physical and platform attribute. The 2600K has a 3.40 GHz base clock versus 2.80 GHz on the 3840QM, but both boost to 3.80 GHz. The 2600K is a 95 W desktop chip on Intel Socket 1155, while the 3840QM is a 45 W mobile chip on Intel BGA 1224. Process node differs: 32 nm for Sandy Bridge against 22 nm for Ivy Bridge. Transistor count jumps from 1,160 million to 1,400 million, while die size shrinks from 216 mm² to 160 mm². The integrated graphics move from Intel HD 3000 to Intel HD 4000. The 2600K supports PCIe Gen 2 with 16 lanes (CPU only); the 3840QM has no recorded PCIe data. Memory bandwidth is recorded only for the 2600K at 25.6 GB/s. The 2600K has an unlocked multiplier, the 3840QM does not. The 2600K has a launch MSRP of $317; the 3840QM has none recorded. Release dates differ: January 2011 versus September 2012. The 2600K is end-of-life; the 3840QM has no production status recorded.

Head-to-Head Benchmarks

The head-to-head results split cleanly along benchmark family lines. In Cinebench R15 multicore, the 3840QM scores 498 against 469 for the 2600K, a 5.8% advantage. Cinebench R15 single-core shows the 3840QM ahead with 70 versus 66, a 5.7% margin. Cinebench R20 multicore extends the 3840QM's lead to 2079 against 1955, a 6% difference, and R20 single-core gives 293 against 275, also a 6.1% margin. Cinebench R23 multicore repeats the pattern: 4952 versus 4657, a 6% lead, while R23 single-core gives 699 versus 657, again 6% in favor of the 3840QM. The Geekbench results reverse the picture entirely. Geekbench multicore scores 2613 for the 2600K against 2111 for the 3840QM, a 23.8% lead for the desktop chip. Geekbench single-core records 768 versus 628, a 22.3% margin for the 2600K. Across the eight recorded tests, the 3840QM wins 6 times and the 2600K wins twice, with the magnitude of the 2600K's Geekbench wins being roughly four times larger than the 3840QM's Cinebench margins.

Where Each One Wins

The i7-3840QM is the winner in every Cinebench test, spanning R15, R20, and R23, in both single-core and multicore modes. These results indicate a consistent edge in rendering-style workloads, with margins between 5.7% and 6.1%. The 3840QM achieves these wins while drawing a 45 W TDP, over half the 95 W TDP of the 2600K, making it the stronger option for sustained multi-threaded rendering tasks in a mobile or thermally constrained platform. The i7-2600K wins decisively in Geekbench, with a 23.8% multicore lead and a 22.3% single-core lead. The 2600K also matches the 3840QM's boost clock of 3.80 GHz while starting from a higher 3.40 GHz base clock, and it offers an unlocked multiplier for overclocking, a feature the 3840QM lacks. For users whose workloads correlate with Geekbench scores, the 2600K is clearly ahead. The 2600K also carries the higher average benchmark score of 1433 versus 1416, though this aggregate difference is small. The 2600K's nearest rivals in the database include the Intel Core i7-4712HQ at 1436 with a -0.2% delta and the AMD Ryzen 5 2400G at 1439 with -0.4%, placing it in a tight cluster. The 3840QM's nearest rivals include the AMD Ryzen 7 2700U at 1415 with 0.1% delta and the Intel Core i7-2700K at 1419 with -0.2%, also a compact grouping. Ultimately, the 3840QM wins the rendering-oriented benchmark suite, while the 2600K takes the Geekbench titles and the higher average score.