Intel Core i7-6850K vs Intel Xeon E5-1660 v3 Comparison

The Intel Xeon E5-1660 v3 and Intel Core i7-6850K are two end-of-life LGA 2011-3 processors that, despite their different market segments and generations, land within 0.1% of each other in average benchmark score. The Xeon E5-1660 v3, a Haswell-EP server/workstation part, edges out the Broadwell-E desktop Core i7 in every single benchmark recorded, with a consistent 10% advantage across both multi-core and single-core tests. The data indicates a clear, if narrow, performance hierarchy: the Xeon leads in all measured workloads, while the Core i7 counters with a more recent architecture, higher base clocks, and a higher memory bandwidth rating.

Where Each One Wins

The benchmark results are unambiguous: the Intel Xeon E5-1660 v3 wins in every recorded test category. Out of six head-to-head comparisons, it takes all six victories. In multi-core workloads, the Xeon’s advantage stems from its 8 cores and 16 threads, compared to the Core i7-6850K’s 6 cores and 12 threads. This translates to a 10.3% lead in Cinebench R15 multi-core (1074 vs 974) and a 10.2% lead in Cinebench R20 multi-core (4475 vs 4062). The pattern holds in the heavier Cinebench R23 multi-core test, where the Xeon scores 10656 against the Core i7’s 9672, a 10.2% gap.

Surprisingly, the Xeon also wins in single-core performance, despite the Core i7’s higher base clock (3.60 GHz vs 3.00 GHz) and boost clock (3.80 GHz vs 3.50 GHz). The Xeon’s single-core scores are 151, 631, and 1504 in Cinebench R15, R20, and R23 respectively, versus the Core i7’s 137, 573, and 1365. Each of these represents a 10.1% to 10.2% advantage for the Xeon. This suggests that the architectural efficiency of the Haswell-EP design, combined with its larger 20 MB L3 cache, compensates for the clock speed deficit. For users prioritizing raw throughput, the Xeon is the choice; the Core i7 offers no benchmark win to claim in this data set.

FAQ

Q: Which processor has the higher average benchmark score?

A: The Intel Xeon E5-1660 v3 has an average benchmark score of 3082, while the Intel Core i7-6850K has an average score of 3079. The Xeon leads by a margin of 0.1%.

Q: How do the two processors compare in multi-core Cinebench R23 performance?

A: The Xeon E5-1660 v3 scores 10656 in Cinebench R23 multi-core, which is 10.2% higher than the Core i7-6850K’s score of 9672.

Q: Does the Core i7-6850K win any benchmark in the head-to-head comparison?

A: No. The Core i7-6850K has zero wins in the six recorded head-to-head benchmarks, all of which are won by the Xeon E5-1660 v3.

Q: What is the difference in core and thread counts?

A: The Xeon E5-1660 v3 has 8 cores and 16 threads, whereas the Core i7-6850K has 6 cores and 12 threads.

Q: Which processor supports ECC memory?

A: The Xeon E5-1660 v3 supports ECC memory, while the Core i7-6850K does not. Both support DDR4 with a quad-channel memory bus.

Q: What is the launch MSRP of the Core i7-6850K?

A: The Core i7-6850K has a launch MSRP of $617. The Xeon E5-1660 v3 has no launch MSRP listed in the data.

Head-to-Head Benchmarks

The benchmark data is remarkably consistent, with the Xeon E5-1660 v3 achieving a near-uniform 10% lead over the Core i7-6850K across all six tests. The largest margin is in Cinebench R15 multi-core, where the Xeon scores 1074 versus the Core i7’s 974, a delta of 10.3%. This test benefits most from the Xeon’s additional two cores and four threads.

In single-core tests, the Xeon’s advantage is nearly identical. Cinebench R15 single-core shows 151 vs 137, a 10.2% lead. The same delta appears in Cinebench R20 single-core (631 vs 573, 10.1%) and Cinebench R23 single-core (1504 vs 1365, 10.2%). This is notable because the Core i7 has a higher boost clock of 3.80 GHz compared to the Xeon’s 3.50 GHz. The data suggests that the Xeon’s older Haswell architecture, when combined with its larger cache, delivers superior per-clock performance in these rendering workloads.

The multi-core results across all three Cinebench versions (R15, R20, R23) show deltas of 10.3%, 10.2%, and 10.2% respectively. This consistency indicates a stable performance gap that scales with workload intensity. The Xeon’s average score of 3082 vs the Core i7’s 3079 places them at the same 52nd percentile among all CPUs, meaning the 10% difference in these specific tests is not enough to shift their overall ranking. The Core i7 does have additional Geekbench scores (6629 multi-core, 1217 single-core) that are not available for the Xeon, but these do not affect the head-to-head comparison.

Specification Differences

The two processors differ in several fundamental specifications beyond their core counts. The Xeon E5-1660 v3 operates at a base clock of 3.00 GHz and a boost clock of 3.50 GHz, while the Core i7-6850K is faster on paper with a base clock of 3.60 GHz and a boost clock of 3.80 GHz. Despite this, the Xeon wins all benchmarks, underscoring that clock speed alone does not determine performance here.

The Xeon has 8 cores and 16 threads, versus the Core i7’s 6 cores and 12 threads. Cache sizes also differ: the Xeon features 20 MB of shared L3 cache, while the Core i7 has 15 MB. Both have the same 64 KB L1 and 256 KB L2 cache per core. Memory bandwidth is another differentiator, with the Core i7 rated at 76.8 GB/s versus the Xeon’s 68.3 GB/s, despite both using quad-channel DDR4.

ECC memory support is exclusive to the Xeon, which is typical for its server/workstation market segment. The Core i7 is classified as a desktop part, while the Xeon is a server/workstation part. The launch MSRP for the Core i7 is $617; the Xeon has no listed launch MSRP. Both processors have an unlocked multiplier, use the same Intel Socket 2011-3, and have a TDP of 140 W. They also share the same PCIe configuration: Gen 3 with 40 lanes from the CPU.

Architecture Differences

The Xeon E5-1660 v3 and Core i7-6850K come from different architectural generations and manufacturing processes. The Xeon is based on the Haswell architecture, specifically the Haswell-EP codename, and is built on a 22 nm process node. The Core i7 uses the Broadwell architecture, codenamed Broadwell-E, and is manufactured on a smaller 14 nm process node. This makes the Core i7 the more modern design, though the Xeon’s larger die size of 356 mm² versus the Core i7’s 246 mm² suggests a different transistor layout and density.

Transistor counts also differ significantly. The Xeon packs 2,600 million transistors, while the Core i7 contains 3,400 million. The Core i7’s higher transistor count on a smaller node is consistent with its newer architecture. The Xeon is from the Xeon E5 (Haswell-EP) generation, released in September 2014, while the Core i7 is from the Core i7 (Broadwell-E) generation, released in May 2016. Both are end-of-life products.

The Xeon’s architecture includes support for ECC memory, a feature absent from the Core i7. This aligns with the Xeon’s server/workstation positioning. The L3 cache difference (20 MB vs 15 MB) is a direct consequence of the core count difference, but the Xeon’s single-core wins suggest that the Haswell-EP architecture has an efficiency advantage in these specific Cinebench workloads. The Core i7’s higher memory bandwidth (76.8 GB/s vs 68.3 GB/s) does not translate into a performance win in the tested benchmarks, indicating that memory bandwidth is not the limiting factor in these tests. Both processors lack integrated graphics and share the same 40-lane PCIe Gen 3 interface, making them comparable in platform expansion capability.