Atom x5-E3940 vs Xeon E5-2666 V3
Aggregate performance score
Xeon E5-2666 V3 outperforms Atom x5-E3940 by a whopping 625% based on our aggregate benchmark results.
Primary details
Comparing Xeon E5-2666 V3 and Atom x5-E3940 processor market type (desktop or notebook), architecture, sales start time and price.
| Place in the ranking | 866 | 2324 |
| Place by popularity | not in top-100 | not in top-100 |
| Market segment | Server | Laptop |
| Series | no data | 5x Intel Atom |
| Power efficiency | 6.25 | 11.63 |
| Architecture codename | Haswell-EP (2014−2015) | Apollo Lake (2014−2016) |
| Release date | 13 November 2014 (10 years ago) | 30 August 2014 (10 years ago) |
Detailed specifications
Xeon E5-2666 V3 and Atom x5-E3940 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 | 10 (Deca-Core) | 4 (Quad-Core) |
| Threads | 20 | 4 |
| Base clock speed | 2.9 GHz | 1.6 GHz |
| Boost clock speed | 3.5 GHz | 1.8 GHz |
| L1 cache | 64K (per core) | 56K (per core) |
| L2 cache | 256K (per core) | 2 MB (shared) |
| L3 cache | 25 MB (shared) | 0 KB |
| Chip lithography | 22 nm | 14 nm |
| Die size | 356 mm2 | no data |
| Maximum case temperature (TCase) | no data | 103 °C |
| Number of transistors | 2,600 million | no data |
| 64 bit support | + | + |
| Windows 11 compatibility | no data | - |
Compatibility
Information on Xeon E5-2666 V3 and Atom x5-E3940 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 | 2 | 1 (Uniprocessor) |
| Socket | 2011-3 | Intel BGA 1296 |
| Power consumption (TDP) | 135 Watt | 10 Watt |
Technologies and extensions
Technological solutions and additional instructions supported by Xeon E5-2666 V3 and Atom x5-E3940. You'll probably need this information if you require some particular technology.
| AES-NI | + | + |
| AVX | + | - |
| vPro | + | no data |
| Enhanced SpeedStep (EIST) | + | + |
| TSX | + | - |
Security technologies
Xeon E5-2666 V3 and Atom x5-E3940 technologies aimed at improving security, for example, by protecting against hacks.
| TXT | + | + |
Virtualization technologies
Virtual machine speed-up technologies supported by Xeon E5-2666 V3 and Atom x5-E3940 are enumerated here.
| VT-d | + | + |
| VT-x | + | + |
Memory specs
Types, maximum amount and channel quantity of RAM supported by Xeon E5-2666 V3 and Atom x5-E3940. Depending on the motherboard, higher memory frequencies may be supported.
| Supported memory types | DDR3, DDR4 2133 MHz Quad-channel | DDR3-1866 |
| Maximum memory size | no data | 8 GB |
Graphics specifications
General parameters of integrated GPUs, if any.
| Integrated graphics card | no data | Intel HD Graphics 500 |
Peripherals
Specifications and connection of peripherals supported by Xeon E5-2666 V3 and Atom x5-E3940.
| PCIe version | 3.0 | 2.0 |
| PCI Express lanes | 40 | 4 |
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.
Pros & cons summary
| Performance score | 8.92 | 1.23 |
| Recency | 13 November 2014 | 30 August 2014 |
| Physical cores | 10 | 4 |
| Threads | 20 | 4 |
| Chip lithography | 22 nm | 14 nm |
| Power consumption (TDP) | 135 Watt | 10 Watt |
Xeon E5-2666 V3 has a 625.2% higher aggregate performance score, an age advantage of 2 months, and 150% more physical cores and 400% more threads.
Atom x5-E3940, on the other hand, has a 57.1% more advanced lithography process, and 1250% lower power consumption.
The Xeon E5-2666 V3 is our recommended choice as it beats the Atom x5-E3940 in performance tests.
Be aware that Xeon E5-2666 V3 is a server/workstation processor while Atom x5-E3940 is a notebook one.
Should you still have questions on choice between Xeon E5-2666 V3 and Atom x5-E3940, ask them in Comments section, and we shall answer.
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