Xeon E5645 vs E3-1271 v3
Aggregate performance score
Xeon E3-1271 v3 outperforms Xeon E5645 by a considerable 49% based on our aggregate benchmark results.
Primary details
Comparing Xeon E3-1271 v3 and Xeon E5645 processor market type (desktop or notebook), architecture, sales start time and price.
| Place in the ranking | 1270 | 1620 |
| Place by popularity | not in top-100 | not in top-100 |
| Cost-effectiveness evaluation | no data | 1.38 |
| Market segment | Server | Server |
| Power efficiency | 5.60 | 3.76 |
| Architecture codename | no data | Westmere-EP (2010−2011) |
| Release date | 1 April 2014 (10 years ago) | 16 March 2010 (14 years ago) |
| Launch price (MSRP) | no data | $294 |
Cost-effectiveness evaluation
Performance per price, higher is better.
Detailed specifications
Xeon E3-1271 v3 and Xeon E5645 basic parameters such as number of cores, number of threads, base frequency and turbo boost clock, lithography, cache size and multiplier lock state. These parameters indirectly say of CPU speed, though for more precise assessment you have to consider their test results.
| Physical cores | 4 (Quad-Core) | 6 (Hexa-Core) |
| Threads | 8 | 12 |
| Base clock speed | 3.6 GHz | 2.4 GHz |
| Boost clock speed | 4 GHz | 2.67 GHz |
| Bus rate | 5 GT/s | no data |
| L1 cache | no data | 64 KB (per core) |
| L2 cache | no data | 256 KB (per core) |
| L3 cache | 8 MB Intel® Smart Cache | 12 MB (shared) |
| Chip lithography | 22 nm | 32 nm |
| Die size | no data | 239 mm2 |
| Maximum core temperature | no data | 76 °C |
| Number of transistors | no data | 1,170 million |
| 64 bit support | + | + |
| Windows 11 compatibility | - | - |
Compatibility
Information on Xeon E3-1271 v3 and Xeon E5645 compatibility with other computer components: motherboard (look for socket type), power supply unit (look for power consumption) etc. Useful when planning a future computer configuration or upgrading an existing one. Note that power consumption of some processors can well exceed their nominal TDP, even without overclocking. Some can even double their declared thermals given that the motherboard allows to tune the CPU power parameters.
| Number of CPUs in a configuration | 1 | 2 |
| Socket | FCLGA1150 | FCLGA1366,LGA1366 |
| Power consumption (TDP) | 80 Watt | 80 Watt |
Technologies and extensions
Technological solutions and additional instructions supported by Xeon E3-1271 v3 and Xeon E5645. You'll probably need this information if you require some particular technology.
| Instruction set extensions | Intel® SSE4.1, Intel® SSE4.2, Intel® AVX2 | Intel® SSE4.2 |
| AES-NI | + | + |
| Enhanced SpeedStep (EIST) | + | + |
| Turbo Boost Technology | 2.0 | 1.0 |
| Hyper-Threading Technology | + | + |
| TSX | + | - |
| Idle States | + | + |
| Thermal Monitoring | + | - |
| Flex Memory Access | + | no data |
| SIPP | + | - |
| Demand Based Switching | no data | + |
| PAE | no data | 40 Bit |
| Fast Memory Access | + | no data |
Security technologies
Xeon E3-1271 v3 and Xeon E5645 technologies aimed at improving security, for example, by protecting against hacks.
| TXT | + | + |
| EDB | + | + |
| Secure Key | + | no data |
| Identity Protection | + | - |
| OS Guard | + | no data |
| Anti-Theft | + | no data |
Virtualization technologies
Virtual machine speed-up technologies supported by Xeon E3-1271 v3 and Xeon E5645 are enumerated here.
| VT-d | + | + |
| VT-x | + | + |
| EPT | + | + |
Memory specs
Types, maximum amount and channel quantity of RAM supported by Xeon E3-1271 v3 and Xeon E5645. Depending on the motherboard, higher memory frequencies may be supported.
| Supported memory types | DDR3L-1333, DDR3L-1600 | DDR3 |
| Maximum memory size | 32 GB | 288 GB |
| Max memory channels | 2 | 3 |
| Maximum memory bandwidth | 25.6 GB/s | 32 GB/s |
| ECC memory support | + | + |
Peripherals
Specifications and connection of peripherals supported by Xeon E3-1271 v3 and Xeon E5645.
| PCIe version | 3.0 | 2.0 |
| PCI Express lanes | 16 | no data |
Synthetic benchmark performance
Various benchmark results of the processors in comparison. Overall score is measured in points in 0-100 range, higher is better.
Combined synthetic benchmark score
This is our combined benchmark performance rating. We are regularly improving our combining algorithms, but if you find some perceived inconsistencies, feel free to speak up in comments section, we usually fix problems quickly.
Passmark
Passmark CPU Mark is a widespread benchmark, consisting of 8 different types of workload, including integer and floating point math, extended instructions, compression, encryption and physics calculation. There is also one separate single-threaded scenario measuring single-core performance.
GeekBench 5 Single-Core
GeekBench 5 Single-Core is a cross-platform application developed in the form of CPU tests that independently recreate certain real-world tasks with which to accurately measure performance. This version uses only a single CPU core.
GeekBench 5 Multi-Core
GeekBench 5 Multi-Core is a cross-platform application developed in the form of CPU tests that independently recreate certain real-world tasks with which to accurately measure performance. This version uses all available CPU cores.
Pros & cons summary
| Performance score | 4.73 | 3.18 |
| Recency | 1 April 2014 | 16 March 2010 |
| Physical cores | 4 | 6 |
| Threads | 8 | 12 |
| Chip lithography | 22 nm | 32 nm |
Xeon E3-1271 v3 has a 48.7% higher aggregate performance score, an age advantage of 4 years, and a 45.5% more advanced lithography process.
Xeon E5645, on the other hand, has 50% more physical cores and 50% more threads.
The Xeon E3-1271 v3 is our recommended choice as it beats the Xeon E5645 in performance tests.
Should you still have questions on choice between Xeon E3-1271 v3 and Xeon E5645, ask them in Comments section, and we shall answer.
Similar processor comparisons
We picked several similar comparisons of processors in the same market segment and performance relatively close to those reviewed on this page.
