Intel Core i7-3820QM vs Intel Xeon E3-1226 v3 Comparison

The Intel Core i7-3820QM and the Intel Xeon E3-1226 v3 are both 22 nm, four-core Intel parts from the same era, but they are built for different worlds: one is a mobile processor for laptops, the other a workstation chip for desktop servers. The benchmark data shows a surprisingly consistent picture: the mobile i7 wins every single head-to-head test, albeit by narrow margins, while the Xeon brings platform features like ECC memory and a different socket. This analysis breaks down where each chip actually makes sense.

Where Each One Wins

Based strictly on the head-to-head benchmark results, the Intel Core i7-3820QM wins in every measured category. It takes the Cinebench R15, R20, and R23 tests in both single-core and multi-core variants, giving it a clean 6-0 sweep. The margins are small—between 1.5% and 1.9%—but they are consistent across all six tests. The i7-3820QM's edge comes from its 8 threads versus the Xeon's 4 threads, which helps in multi-threaded workloads, and its slightly higher single-thread performance in these specific benchmarks.

The Intel Xeon E3-1226 v3, however, wins in areas not covered by raw compute benchmarks. It supports ECC memory, which the i7-3820QM does not, making it the correct choice for systems where data integrity is non-negotiable. The Xeon also has a higher base clock (3.30 GHz vs 2.70 GHz) and uses the LGA 1150 socket, which is a desktop platform, whereas the i7-3820QM is a mobile BGA 1224 part. The Xeon is also listed as end-of-life, while the i7's status is not specified. So, the Xeon wins on platform suitability for servers and workstations, even though it loses on sheer benchmark scores.

Architecture Differences

The two CPUs come from different Intel microarchitectures. The i7-3820QM is built on Ivy Bridge, while the Xeon E3-1226 v3 is based on Haswell (specifically Haswell-WS for workstations). Both use the same 22 nm process node, and both have identical transistor counts (1,400 million) and die sizes (160 mm²). The cache hierarchy is also identical: 64 KB L1 per core, 256 KB L2 per core, and 8 MB of shared L3.

The critical architectural divergence is in threading. The i7-3820QM has 8 threads (4 cores with Hyper-Threading), while the Xeon E3-1226 v3 has only 4 threads (4 cores without Hyper-Threading). This explains the i7's consistent lead in multi-core benchmarks. The base clocks differ significantly: 2.70 GHz for the i7 versus 3.30 GHz for the Xeon. Both boost to the same 3.70 GHz.

Integrated graphics also differ: the i7-3820QM ships with Intel HD 4000, while the Xeon has Intel HD P4600. The Xeon supports DDR3 memory with a stated bandwidth of 25.6 GB/s and has 16 PCIe Gen 3 lanes (CPU only); the i7's memory support and PCIe configuration are not listed in the data. The Xeon is the only one of the two with ECC memory support. The i7 is a mobile chip (BGA 1224), while the Xeon is a server/workstation chip (Socket 1150). The Xeon's launch MSRP is $213; the i7 has no listed launch price.

Head-to-Head Benchmarks

The head-to-head results show a consistent, if modest, advantage for the i7-3820QM across the board. In Cinebench R15 multi-core, the i7 scores 481 against the Xeon's 472, a 1.9% win. The single-core R15 test is closer: 67 versus 66, a 1.5% margin. Moving to Cinebench R20, the i7 posts 2006 multi-core versus 1970 for the Xeon (1.8% delta), and 283 single-core versus 278 (1.8% delta). The pattern holds in Cinebench R23: 4777 multi-core versus 4692 (1.8% delta) and 674 single-core versus 662 (1.8% delta).

These numbers tell a clear story. The i7-3820QM is faster in every test, but the differences are small enough that real-world applications would be hard-pressed to show a meaningful gap. The 1.8-1.9% multi-core advantage is attributable to the extra 4 threads; the 1.5-1.8% single-core edge is likely due to the i7's higher boost clock behavior in these tests, despite the Xeon's higher base clock. The Xeon's higher base clock (3.30 GHz) does not translate into a win because the i7's boost clock matches it at 3.70 GHz, and the i7's architecture seems to extract slightly more performance per clock in these Cinebench loads.

The average benchmark scores reflect this near-tie. The i7-3820QM has an average score of 1366, while the Xeon E3-1226 v3 sits at 1357. Both CPUs land in the 36th percentile of all CPUs, meaning they are essentially peers in the overall performance distribution. The i7's nearest rivals include the Intel Xeon D-1521 (deltaPct -0.1%), while the Xeon's nearest rivals include the Intel Core i5-6500T (deltaPct -0.3%). The data shows no scenario where the Xeon wins a compute test, but the platform features are where it differentiates.

FAQ

Q: Which CPU has better multi-threaded performance?

A: The Intel Core i7-3820QM wins all three multi-core Cinebench tests (R15, R20, R23) with margins of 1.8-1.9%. Its 8 threads versus the Xeon's 4 threads give it a consistent, though small, advantage in multi-threaded workloads.

Q: Does the Xeon E3-1226 v3 support ECC memory?

A: Yes. The Xeon E3-1226 v3 lists ECC memory as supported, while the i7-3820QM does not list ECC support. This makes the Xeon the only option of the two for systems requiring error-correcting memory.

Q: Are the cache sizes different between these two CPUs?

A: No. Both have identical cache hierarchies: 64 KB L1 per core, 256 KB L2 per core, and 8 MB of shared L3.

Q: Which CPU has a higher base clock speed?

A: The Xeon E3-1226 v3 has a base clock of 3.30 GHz, which is higher than the i7-3820QM's 2.70 GHz. However, both have the same boost clock of 3.70 GHz.

Q: What is the market segment for each CPU?

A: The i7-3820QM is a Mobile processor with a BGA 1224 socket, while the Xeon E3-1226 v3 is a Server/Workstation processor with an Intel Socket 1150.

Q: Which CPU has a higher average benchmark score?

A: The i7-3820QM has an average benchmark score of 1366, which is 9 points higher than the Xeon's 1357. Both are in the 36th percentile of all CPUs.

The Verdict

The data is unambiguous on compute performance: the Intel Core i7-3820QM is the faster CPU in every benchmark recorded. If your priority is raw Cinebench scores, the i7-3820QM is the pick, even though its wins are narrow. The 8-thread configuration gives it a real, if modest, edge in multi-core rendering tasks, and it also edges out the Xeon in single-core tests.

The Xeon E3-1226 v3, however, is the only sensible choice for specific use cases. Its ECC memory support is a hard requirement for many server and workstation environments where a bit-flip is unacceptable. Its higher base clock of 3.30 GHz and desktop Socket 1150 make it a more natural fit for always-on, socketed systems. The Xeon also has a listed launch MSRP of $213, while the i7 has no listed price.

For a laptop or mobile workstation, the i7-3820QM is the only option anyway, given its BGA 1224 socket. For a stationary server or workstation where ECC is needed, the Xeon is the one to buy, accepting the small benchmark deficit. The i7-3820QM is the performance leader by a hair; the Xeon E3-1226 v3 is the platform leader where stability and data integrity matter more than a 1.9% Cinebench delta.

Specification Differences

| Specification | Intel Core i7-3820QM | Intel Xeon E3-1226 v3 |

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

| Threads | 8 | 4 |

| Base Clock | 2.70 GHz | 3.30 GHz |

| Boost Clock | 3.70 GHz | 3.70 GHz |

| TDP | 45 W | 84 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 | Not listed | DDR3 |

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

| ECC Memory | No | Yes |

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

| Integrated Graphics | Intel HD 4000 | Intel HD P4600 |

| Market Segment | Mobile | Server/Workstation |

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

| Release Date | 2012-04-28 | 2014-05-10 |

| Launch MSRP | Not listed | $213 |

| Part Number | SR0MK | SR1R0 |