Intel Core i7-6700 vs Intel Xeon E3-1565L v5 Comparison

Where Each One Wins

The benchmark data splits these two Skylake-era processors into clearly defined roles. The Intel Core i7-6700 dominates the head-to-head record with 15 wins out of 17 tests, while the Intel Xeon E3-1565L v5 takes only 2 wins. The i7-6700 is the choice for general compute throughput, single-threaded responsiveness, and memory-heavy workloads. The Xeon E3-1565L v5 counters in two specific niche tests: prime number generation and physics simulation.

The i7-6700 wins every Cinebench iteration across R15, R20, and R23, both single-core and multi-core. Its advantage in multi-core Cinebench tests is consistent at 9.7% across all three versions. Single-core Cinebench wins range from 9.1% to 9.7%. This consistency suggests a clock-speed-driven advantage rather than an architectural edge, since both chips share the same Skylake core design.

In Passmark workloads, the i7-6700 wins 10 of 12 tests. Its largest margins appear in random string sorting at 24.8%, extended instructions at 24.4%, and data compression at 20%. These are memory-latency-sensitive and SIMD-heavy workloads where the higher boost clock matters. The i7-6700 also wins data encryption by 19%, integer math by 9.9%, and multithread by 9.9%.

The Xeon E3-1565L v5 wins passmark_find_prime_numbers with a score of 43 versus 27, a 37.2% advantage. It also wins passmark_physics with 794 versus 558, a 29.7% margin. These are curious results given the Xeon's lower clocks. The prime number test may benefit from the Xeon's different power management behavior or cache handling, while the physics test likely reflects a workload pattern that does not scale with raw frequency.

For users prioritizing everyday application performance, video encoding, compilation, or office multitasking, the i7-6700 is the clear winner. For specialized workloads involving prime-number sieving or physics calculations, the Xeon E3-1565L v5 holds a meaningful edge despite its lower clock speeds.

Architecture Differences

Both processors use Intel's 14 nm process node and the Skylake microarchitecture. The Core i7-6700 carries the Skylake codename, while the Xeon E3-1565L v5 uses Skylake-H, a variant aimed at mobile and embedded platforms. The transistor count and die size are recorded only for the Xeon: 2,300 million transistors on a 171 mm² die. The i7-6700's transistor count and die size are not listed in the database.

Core and thread counts are identical: 4 cores and 8 threads each. Cache hierarchies match exactly, with 64 KB L1 per core, 256 KB L2 per core, and 8 MB shared L3. Memory support is also identical: DDR3 and DDR4 in dual-channel configuration with 34.1 GB/s bandwidth. Both support PCIe Gen 3 with 16 lanes from the CPU.

The key differentiators are socket, TDP, clock speeds, integrated graphics, ECC support, and market segment. The i7-6700 uses Intel Socket 1151 and is classified as a desktop part. The Xeon E3-1565L v5 uses Intel BGA 1440, a soldered mobile/embedded socket, and targets the server/workstation segment. The Xeon's TDP is 35 watts versus 65 watts for the i7-6700, reflecting its efficiency-focused design.

Integrated graphics differ substantially. The i7-6700 includes HD Graphics 530, while the Xeon E3-1565L v5 includes Iris Pro Graphics P580, a significantly more capable GPU for a server-class chip. ECC memory support is exclusive to the Xeon, a standard feature for reliability-oriented workloads.

The Xeon also has a later release date, entering the database in May 2016 versus June 2015 for the i7-6700. Both processors are end-of-life and have locked multipliers. The i7-6700's part number is SR2L2; the Xeon's is SR2R8.

FAQ

Q: Which processor has the higher clock speed?

A: The Intel Core i7-6700 runs at a 3.40 GHz base clock and 4.00 GHz boost clock. The Intel Xeon E3-1565L v5 runs at a 2.50 GHz base clock and 3.50 GHz boost clock.

Q: Does the Xeon support ECC memory?

A: Yes, the Intel Xeon E3-1565L v5 supports ECC memory. The Intel Core i7-6700 does not.

Q: Are these CPUs compatible with the same motherboard?

A: No. The i7-6700 uses Intel Socket 1151, while the Xeon E3-1565L v5 uses Intel BGA 1440. The Xeon is soldered to its board, so they are not interchangeable.

Q: Which chip has better integrated graphics?

A: The Xeon E3-1565L v5 includes Iris Pro Graphics P580, while the i7-6700 includes HD Graphics 530. The database does not provide benchmark scores for either iGPU, but the Iris Pro lineup is positioned above HD Graphics in Intel's tier structure.

Q: Why does the Xeon win some Passmark tests despite lower clocks?

A: The Xeon wins passmark_find_prime_numbers by 37.2% (43 versus 27) and passmark_physics by 29.7% (794 versus 558). These specific workloads appear to favor the Xeon's power management or cache behavior over raw clock speed.

Q: What is the average benchmark score for each chip?

A: The i7-6700 has an average benchmark score of 11074, while the Xeon E3-1565L v5 averages 10320. Both sit at the 66th percentile among all CPUs in the database.

Specification Differences

| Specification | Intel Core i7-6700 | Intel Xeon E3-1565L v5 |

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

| Base Clock | 3.40 GHz | 2.50 GHz |

| Boost Clock | 4.00 GHz | 3.50 GHz |

| TDP | 65 W | 35 W |

| Socket | Intel Socket 1151 | Intel BGA 1440 |

| Codename | Skylake | Skylake-H |

| Generation | Core i7 (Skylake) | Xeon E3 (Skylake-H) |

| Transistors | Not listed | 2,300 million |

| Die Size | Not listed | 171 mm² |

| ECC Memory | No | Yes |

| Integrated Graphics | HD Graphics 530 | Iris Pro Graphics P580 |

| Market Segment | Desktop | Server/Workstation |

| Release Date | June 2015 | May 2016 |

| Launch MSRP | $303 | $417 |

| Part Number | SR2L2 | SR2R8 |

The specification table shows two chips with identical core counts, cache sizes, memory support, and PCIe configuration. The differences cluster around power, packaging, reliability features, and clock speeds. The Xeon's 35 W TDP is less than the i7-6700's 65 W, making it suitable for compact or passively cooled systems. The i7-6700's higher clocks give it a performance edge in most measured workloads.

Head-to-Head Benchmarks

The i7-6700 wins the Cinebench suite by a narrow but consistent margin. In Cinebench R15 multi-core, it scores 688 against 627, a 9.7% advantage. Single-core R15 shows 96 versus 88, a 9.1% edge. The pattern repeats in R20 multi-core (2867 versus 2614, 9.7%) and R20 single-core (404 versus 369, 9.5%). Cinebench R23 multi-core delivers 6828 versus 6226 (9.7%) and single-core 964 versus 879 (9.7%). These results indicate that the i7-6700's clock advantage translates directly into rendering performance.

Passmark integer math shows 25651 for the i7-6700 versus 23335 for the Xeon, a 9.9% win. Floating point math follows at 15840 versus 14547, an 8.9% margin. Multithread score is 8051 versus 7325, also 9.9%. Single-thread performance is 2277 versus 1970, a 15.6% advantage for the i7-6700, its largest win outside the specialized Passmark tests.

The i7-6700's biggest victories come in data-oriented workloads. Random string sorting scores 14406 versus 11543, a 24.8% margin. Extended instructions hit 7505 versus 6031, a 24.4% edge. Data compression reaches 113748 versus 94771, a 20% advantage. Data encryption is 2753 versus 2314, a 19% win. These tests suggest the i7-6700 handles memory-heavy and instruction-dense workloads with noticeably more headroom.

The Xeon E3-1565L v5 takes two tests decisively. Prime number finding scores 43 versus 27, a 37.2% advantage. Physics simulation scores 794 versus 558, a 29.7% lead. These are the only tests where the Xeon outperforms, and the margins are substantial. The physics result is particularly notable because it reverses the typical clock-speed relationship seen elsewhere.

The average benchmark scores reflect the overall split: the i7-6700 averages 11074 against 10320 for the Xeon, a difference of about 7% in favor of the desktop part. Both processors sit at the 66th percentile in the global database, meaning they occupy the same performance tier despite their individual workload differences.

The Verdict

The Intel Core i7-6700 is the better all-round processor. It wins 15 of 17 head-to-head tests and holds advantages in every Cinebench workload, all major Passmark categories, and the overall average benchmark score. Its higher base and boost clocks (3.40 GHz and 4.00 GHz versus 2.50 GHz and 3.50 GHz) give it a measurable edge in rendering, encryption, compression, and general multithreaded work. Users building a desktop system on Socket 1151 should choose the i7-6700 for its superior performance and lower launch MSRP of $303.

The Intel Xeon E3-1565L v5 serves a different purpose. Its 35 W TDP, ECC memory support, and BGA 1440 socket target embedded and workstation applications where reliability and power efficiency matter more than raw speed. It wins prime number finding by 37.2% and physics simulation by 29.7%, which makes it intriguing for specialized compute tasks in those domains. Its Iris Pro Graphics P580 also outclasses the i7-6700's HD Graphics 530 on paper, though no benchmark scores are recorded for either iGPU.

The launch MSRP for the Xeon is $417, which is higher than the i7-6700's $303. That price difference, combined with lower clock speeds, makes the Xeon a poor choice for general-purpose desktop use. It is a niche part for systems that require ECC memory, soldered packaging, or minimal power draw. The i7-6700 is the pick for anyone who needs maximum performance from these two Skylake chips in standard desktop workloads. The Xeon only makes sense when its specific features or its two benchmark wins align with the intended use case.