Intel Core i7-5820K vs Intel Xeon E5-4640 v3 Comparison

Head-to-Head Benchmarks

The benchmark data presents a remarkably consistent picture across the entire Cinebench suite. The Intel Xeon E5-4640 v3 wins all six recorded head-to-head comparisons, with the margin staying tightly clustered between 5.5% and 5.9%. This is not a case of one processor dominating in specific workloads while losing in others; the Xeon's advantage is uniform across both single-threaded and multi-threaded tests.

Starting with the multi-core results, which typically matter most for server and workstation workloads, the Xeon E5-4640 v3 scores 888 points in Cinebench R15 multi-core, against 841 for the Core i7-5820K. That translates to a 5.6% lead. The pattern repeats in Cinebench R20 multi-core, where the Xeon posts 3702 against 3508, a 5.5% advantage. In Cinebench R23 multi-core, the Xeon reaches 8816 versus 8354, again 5.5% ahead.

The single-core results tell a similar story, albeit with smaller absolute gaps due to the lower scores involved. In Cinebench R15 single-core, the Xeon scores 125 versus 118, a 5.9% margin. Cinebench R20 single-core shows 522 versus 495, a 5.5% lead. Cinebench R23 single-core records 1244 versus 1179, also 5.5% ahead. The consistency of these margins suggests a systematic advantage rather than workload-specific behavior.

Looking at the overall averages, the database records an average benchmark score of 2550 for the Xeon E5-4640 v3 and 2642 for the Core i7-5820K. This is an interesting inversion: despite losing every head-to-head test, the Core i7-5820K has a higher average score. This occurs because the database includes additional Geekbench results for the Core i7-5820K, which are not available for the Xeon in the recorded data. The Core i7-5820K scores 5464 in Geekbench multi-core and 1174 in single-core, and these results pull its average upward.

Both processors sit at the 49th percentile among all CPUs in the database, meaning they perform better than roughly half of the recorded processors. The Xeon's nearest rivals include the Intel Xeon E5-1650 v3 with an average score of 2545, just 0.2% behind, and the AMD Ryzen 7 4800HS at 2557, which is 0.3% ahead. The Core i7-5820K's nearest rivals include the Intel Xeon E-2274G at 2643, effectively tied, and the Intel Core i9-8950HK at 2641, just 0.1% behind.

Where Each One Wins

The Xeon E5-4640 v3 wins every recorded benchmark comparison, so the use-case split is not about which processor is faster. Instead, the distinction lies in which workloads each processor is designed to handle and which platform features matter more.

The Xeon E5-4640 v3 is classified in the server and workstation segment. Its 12 cores and 24 threads make it naturally suited for heavily parallel workloads such as virtualization, database processing, scientific computing, and content rendering where multiple cores can be fully utilized. The processor supports ECC memory, which is critical for servers and workstations where data integrity is paramount. A memory error in a financial database or a scientific simulation can have severe consequences, and ECC protection helps mitigate that risk.

The Core i7-5820K is a desktop processor, and its 6 cores and 12 threads are sufficient for most desktop applications, including gaming, software development, and general productivity. The processor has an unlocked multiplier, meaning users can adjust the clock speed for overclocking. For enthusiasts building a desktop system with overclocking in mind, the Core i7-5820K offers flexibility that the Xeon does not. The Xeon's multiplier is locked, preventing user overclocking.

The memory bandwidth figures also differ. The Xeon E5-4640 v3 records a memory bandwidth of 59.7 GB/s, while the Core i7-5820K achieves 68.3 GB/s. This is notable because the Core i7-5820K, despite having fewer cores, delivers higher raw memory bandwidth. For workloads that are memory-bandwidth sensitive rather than core-count sensitive, the Core i7-5820K could hold an advantage, even though the recorded benchmarks do not isolate this factor.

PCIe lane allocation is another differentiator. The Xeon provides 40 PCIe Gen 3 lanes from the CPU, while the Core i7-5820K provides 28. Systems requiring many expansion cards, such as multiple GPUs, high-speed storage controllers, or network interfaces, benefit from the Xeon's additional lanes.

The release dates place the Core i7-5820K on the market first, launching in August 2014, while the Xeon E5-4640 v3 arrived in May 2015. Both are now end-of-life products.

Architecture Differences

Both processors share the same fundamental architecture: Haswell, built on Intel's 22 nm process node. The foundry is Intel for both, and both use the same transistor count of 2,600 million and the same die size of 356 mm². The codenames differ slightly, with the Xeon using Haswell-EP and the Core i7 using Haswell-E, but the underlying design is the same Haswell microarchitecture.

The core and thread counts are where the architectures diverge most significantly. The Xeon E5-4640 v3 doubles the Core i7-5820K in both cores (12 versus 6) and threads (24 versus 12). This is the primary reason the Xeon wins all multi-threaded benchmark tests, despite its lower clock speeds.

Clock speeds show a clear trade-off. The Xeon runs at a base clock of 1900 MHz with a boost clock of 2.60 GHz. The Core i7-5820K runs at 3.30 GHz base and 3.60 GHz boost. The Core i7's clocks are substantially higher, yet the Xeon still wins the single-core benchmarks. This indicates that the Xeon's architectural implementation, possibly including better turbo behavior or cache efficiency, compensates for its lower nominal clock speeds in the recorded Cinebench tests.

Cache configuration differs notably. Both have 64 KB of L1 cache per core and 256 KB of L2 cache per core. The L3 cache, however, is 30 MB shared on the Xeon versus 15 MB shared on the Core i7. The Xeon's larger L3 cache is consistent with its server positioning, where working sets are often larger and cache misses are more costly.

Thermal design power also reflects the different design goals. The Xeon is rated at 105 W TDP, while the Core i7-5820K is rated at 140 W. This is counterintuitive given the Xeon has twice the cores, but the lower clock speeds on the Xeon allow it to stay within a lower power envelope. The Core i7's higher clocks require more power, and its unlocked multiplier invites users to push power consumption even higher through overclocking.

Memory support is DDR4 for both, using a quad-channel memory bus. ECC memory support is present on the Xeon but absent on the Core i7. The memory bandwidth figures, as noted, favor the Core i7 at 68.3 GB/s versus 59.7 GB/s for the Xeon.

The Xeon's market segment is server and workstation, while the Core i7 is desktop. The Xeon's part number is SR22L, and the Core i7's is SR20S. The Xeon had a launch MSRP of $2859, while the Core i7 has no recorded launch MSRP in the database.

FAQ

Q: Which processor wins in multi-core performance?

A: The Intel Xeon E5-4640 v3 wins all multi-core Cinebench tests. It scores 888 versus 841 in R15 multi-core, 3702 versus 3508 in R20 multi-core, and 8816 versus 8354 in R23 multi-core. Each margin is 5.5% or 5.6%.

Q: Does the Core i7-5820K win any benchmark?

A: No. The database records six head-to-head benchmark comparisons, and the Xeon E5-4640 v3 wins all six. The Core i7-5820K does have additional Geekbench results in the database, but these are not part of the head-to-head comparison set.

Q: Why does the Xeon win single-core tests despite having a lower clock speed?

A: The Xeon has a base clock of 1900 MHz and boost clock of 2.60 GHz, while the Core i7-5820K runs at 3.30 GHz base and 3.60 GHz boost. Despite this, the Xeon scores 125 versus 118 in R15 single-core, 522 versus 495 in R20 single-core, and 1244 versus 1179 in R23 single-core. The recorded data does not specify the reason, but the Xeon's larger 30 MB L3 cache compared to 15 MB on the Core i7 may contribute.

Q: Can I use ECC memory with the Core i7-5820K?

A: No. The Core i7-5820K does not support ECC memory. The Xeon E5-4640 v3 does support ECC memory, which is a key feature for server and workstation reliability.

Q: Which processor has more PCIe lanes?

A: The Xeon E5-4640 v3 provides 40 PCIe Gen 3 lanes from the CPU, while the Core i7-5820K provides 28 lanes. This gives the Xeon more capacity for expansion cards.

Q: Are these processors still in production?

A: Both are end-of-life products. The Core i7-5820K was released in August 2014, and the Xeon E5-4640 v3 was released in May 2015.

Specification Differences

The table below lists only the specification fields where the two processors differ, based on the recorded data.

| Specification | Intel Xeon E5-4640 v3 | Intel Core i7-5820K |

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

| Cores | 12 | 6 |

| Threads | 24 | 12 |

| Base Clock | 1900 MHz | 3.30 GHz |

| Boost Clock | 2.60 GHz | 3.60 GHz |

| TDP | 105 W | 140 W |

| Codename | Haswell-EP | Haswell-E |

| Generation | Xeon E5 (Haswell-EP) | Core i7 (Haswell-E) |

| L3 Cache | 30 MB (shared) | 15 MB (shared) |

| Memory Bandwidth | 59.7 GB/s | 68.3 GB/s |

| ECC Memory | Yes | No |

| PCIe Lanes | 40 (Gen 3, CPU only) | 28 (Gen 3, CPU only) |

| Market Segment | Server/Workstation | Desktop |

| Release Date | 2015-05-31 | 2014-08-31 |

| Launch MSRP | $2859 | Not recorded |

| Multiplier Unlocked | No | Yes |

| Part Number | SR22L | SR20S |

The two processors share the same socket (Intel Socket 2011-3), architecture (Haswell), process node (22 nm), foundry (Intel), transistor count (2,600 million), die size (356 mm²), L1 cache (64 KB per core), L2 cache (256 KB per core), memory support (DDR4), memory bus (quad-channel), integrated graphics (none), and production status (end-of-life).

The average benchmark score in the database is 2550 for the Xeon and 2642 for the Core i7, but this includes Geekbench results for the Core i7 that are not recorded for the Xeon. In the direct head-to-head comparisons, the Xeon leads by 5.5% to 5.9% across all Cinebench tests. Both processors rank at the 49th percentile among all CPUs in the database. The Xeon's nearest rival is the Intel Xeon E5-1650 v3, just 0.2% behind in average score, while the Core i7-5820K's nearest rival is the Intel Xeon E-2274G, effectively tied at 0% difference.