Intel Core i7-3840QM vs Intel Xeon E3-1240L v3 Comparison

Intel Core i7-3840QM and Intel Xeon E3-1240L v3 are both 4-core, 8-thread Intel processors from the 22 nm era, but they target very different platforms. The i7-3840QM is a mobile part built on Ivy Bridge, while the Xeon E3-1240L v3 is a low-power server/workstation chip on Haswell. The benchmark data shows a narrow but consistent lead for the mobile Core i7 across every single test, while the Xeon counters with drastically lower power draw, ECC memory support, and a socketed platform. The choice between them comes down to whether you need the flexibility of a desktop server platform with ECC and low heat output, or the higher clock speeds and integrated graphics of the mobile chip.

Head-to-Head Benchmarks

The head-to-head results are remarkably one-sided. The Intel Core i7-3840QM wins all six recorded benchmark comparisons, with margins ranging from 2.4% to 2.9%. In Cinebench R15 multicore, the i7-3840QM scores 498 against the Xeon's 486, a 2.5% advantage. The single-core R15 test shows a 2.9% lead, with scores of 70 versus 68. Moving to Cinebench R20, the multicore result is 2079 for the i7 against 2027 for the Xeon, a 2.6% gap. The R20 single-core test shows the same 2.4% margin, with 293 versus 286.

The pattern continues into Cinebench R23, the most demanding of the tests. The i7-3840QM posts 4952 in multicore, while the Xeon E3-1240L v3 manages 4827, again a 2.6% difference. In R23 single-core, the scores are 699 and 681, a 2.6% lead for the mobile chip. There is no test in the database where the Xeon pulls ahead. This is a clean sweep for the i7-3840QM, even though both chips share the same core and thread counts and identical cache hierarchies.

Looking at the broader database context, both processors sit at the 37th percentile among all CPUs, meaning they are essentially peers in overall performance. The i7-3840QM has an average benchmark score of 1416, while the Xeon sits at 1396. The nearest rivals for the i7-3840QM include the AMD Ryzen 7 2700U and Intel Core i5-4460, both with an average score of 1415, putting the i7 just 0.1% ahead of those parts. The Xeon's nearest rivals include the Intel Core i5-6500TE at 1399 and the Xeon E3-1220 v5 at 1401, with the Xeon E3-1240L v3 trailing those by 0.2% to 0.4%. The data indicates that these two chips are effectively interchangeable in raw compute performance, with the i7's advantage being consistent but modest.

Where Each One Wins

The i7-3840QM wins on raw performance in every recorded metric, but the Xeon E3-1240L v3 wins on efficiency and platform capabilities. The i7-3840QM's higher base clock of 2.80 GHz and boost clock of 3.80 GHz, compared to the Xeon's 2000.00 MHz base and 3.00 GHz boost, translate directly into the observed benchmark leads. For workloads that are heavily clock-speed dependent, such as lightly threaded applications, the i7's 2.9% single-core advantage in R15 and 2.6% in R23 makes it the better choice.

However, the Xeon E3-1240L v3 has a massive power advantage. Its TDP is 25 watts, compared to 45 watts for the i7-3840QM. That is an 80% reduction in thermal design power, making the Xeon far easier to cool in a compact server chassis or a low-noise workstation. The Xeon also supports ECC memory, a feature entirely absent from the i7-3840QM. For workloads where data integrity is critical, such as file servers, database hosts, or any always-on compute role, ECC support is a decisive factor. The Xeon's memory bandwidth is also specified at 25.6 GB/s, a figure not recorded for the i7, and it supports PCIe Gen 3 with 16 lanes from the CPU, while the i7's PCIe configuration is not listed in the database.

The i7-3840QM includes Intel HD 4000 integrated graphics, while the Xeon has no integrated graphics at all. This means the i7 can power a display without a discrete GPU, making it viable for a mobile workstation or a compact all-in-one system. The Xeon requires a separate graphics card, which is typical for server platforms. The i7 is also a mobile part on Intel BGA 1224, meaning it is soldered to the motherboard, while the Xeon uses Intel Socket 1150, allowing for socketed installation and replacement.

Architecture Differences

Both processors are built on the same 22 nm process node at Intel, with 1,400 million transistors and a 160 mm² die size. The core and thread counts are identical at 4 cores and 8 threads. The cache layout is also the same: 64 KB of L1 per core, 256 KB of L2 per core, and 8 MB of shared L3 cache. The fundamental architecture differs, however. The i7-3840QM uses the Ivy Bridge architecture, released in 2012, while the Xeon E3-1240L v3 uses Haswell, released in 2014. Haswell is a newer microarchitecture that typically brings improvements in instruction efficiency and power management, though the lower clock speeds of the Xeon negate that advantage in the recorded benchmarks.

The memory support is DDR3 for both, with dual-channel buses. The Xeon explicitly supports ECC memory, which the i7 does not. The Xeon's memory bandwidth is recorded as 25.6 GB/s, while no such figure exists for the i7. The Xeon also has PCIe Gen 3 with 16 lanes from the CPU, a specification not listed for the i7. The i7 integrates Intel HD 4000 graphics, while the Xeon has no integrated GPU. The i7's market segment is Mobile, with a release date of September 2012, while the Xeon is a Server/Workstation part released in May 2014 and is marked as end-of-life. The i7's part number is SR0UU, and the Xeon's is SR1T8.

The Xeon has a recorded launch MSRP of $278. The i7 has no launch MSRP in the database. Both processors have locked multipliers, so neither is designed for overclocking. The i7's generation is listed as Core i7 (Ivy Bridge), while the Xeon's is Xeon E3 (Haswell-WS). The Xeon's production status is end-of-life, while the i7's production status is not specified.

FAQ

Q: Which processor has the higher clock speed?

A: The Intel Core i7-3840QM has a base clock of 2.80 GHz and a boost clock of 3.80 GHz. The Intel Xeon E3-1240L v3 has a base clock of 2000.00 MHz and a boost clock of 3.00 GHz. The i7 is significantly faster in both metrics.

Q: Does the Xeon E3-1240L v3 support ECC memory?

A: Yes, the Xeon E3-1240L v3 supports ECC memory. The Intel Core i7-3840QM does not have ECC memory support.

Q: What is the TDP difference between these two chips?

A: The Intel Core i7-3840QM has a TDP of 45 watts. The Intel Xeon E3-1240L v3 has a TDP of 25 watts, making it 80% more power-efficient on paper.

Q: Which chip has integrated graphics?

A: The Intel Core i7-3840QM includes Intel HD 4000 integrated graphics. The Intel Xeon E3-1240L v3 has no integrated graphics, requiring a discrete GPU for display output.

Q: What are the Cinebench R23 multicore scores?

A: The Intel Core i7-3840QM scores 4952 in Cinebench R23 multicore. The Intel Xeon E3-1240L v3 scores 4827, giving the i7 a 2.6% lead.

Q: Are these processors the same socket type?

A: No. The Intel Core i7-3840QM uses Intel BGA 1224, a soldered mobile socket. The Intel Xeon E3-1240L v3 uses Intel Socket 1150, a socketed desktop/server platform.

The Verdict

The data shows a clear performance winner: the Intel Core i7-3840QM beats the Intel Xeon E3-1240L v3 in every benchmark recorded, with margins between 2.4% and 2.9%. If raw compute speed is the only consideration, the i7-3840QM is the better processor. Its higher base and boost clocks deliver consistent advantages in both single-threaded and multi-threaded workloads, as evidenced by its sweep across all six Cinebench tests.

However, the Xeon E3-1240L v3 is not without merit. Its 25 watt TDP versus the i7's 45 watts makes it dramatically easier to cool and more suitable for dense, low-power server deployments. The ECC memory support is a critical feature for reliability-focused workloads, and the socketed Intel Socket 1150 platform offers upgradeability that the soldered BGA 1224 i7 cannot match. The Xeon also has specified PCIe Gen 3 with 16 lanes, which is not listed for the i7, and a recorded memory bandwidth of 25.6 GB/s.

From a platform perspective, the choice is straightforward. If you are building a low-power server or workstation where ECC memory, socketed installation, and minimal heat output are priorities, the Xeon E3-1240L v3 is the correct pick, despite its lower benchmark scores. If you need the fastest possible execution from these two chips, plus integrated graphics for a mobile or compact system, the i7-3840QM is the one. The i7's performance lead is real but small, and the Xeon's power and platform advantages may outweigh it depending on the use case. The i7-3840QM is the better CPU in a head-to-head benchmark comparison; the Xeon is the better platform for specific server-oriented requirements.

Specification Differences

| Specification | Intel Core i7-3840QM | Intel Xeon E3-1240L v3 |

|----------------|----------------------|------------------------|

| Base Clock | 2.80 GHz | 2000.00 MHz |

| Boost Clock | 3.80 GHz | 3.00 GHz |

| TDP | 45 W | 25 W |

| Socket | Intel BGA 1224 | Intel Socket 1150 |

| Architecture | Ivy Bridge | Haswell |

| Codename | Ivy Bridge | Haswell-WS |

| Generation | Core i7 (Ivy Bridge) | Xeon E3 (Haswell-WS) |

| Memory Support | DDR3 | DDR3 |

| ECC Memory | No | Yes |

| Memory Bandwidth | Not specified | 25.6 GB/s |

| PCIe | Not specified | Gen 3, 16 Lanes (CPU only) |

| Integrated Graphics | Intel HD 4000 | None |

| Market Segment | Mobile | Server/Workstation |

| Production Status | Not specified | End-of-life |

| Release Date | September 2012 | May 2014 |

| Launch MSRP | Not specified | $278 |

| Part Number | SR0UU | SR1T8 |

| Multiplier Unlocked | No | No |