Xeon E5-2666 V3 vs i9-7940X

Primary details

Comparing Core i9-7940X and Xeon E5-2666 V3 processor market type (desktop or notebook), architecture, sales start time and price.

Place in the ranking	402	854
Place by popularity	not in top-100	not in top-100
Cost-effectiveness evaluation	2.94	no data
Market segment	Desktop processor	Server
Series	Intel Core i9	no data
Power efficiency	9.37	6.29
Architecture codename	Skylake (server) (2017−2019)	Haswell-EP (2014−2015)
Release date	30 May 2017 (7 years ago)	13 November 2014 (10 years ago)
Launch price (MSRP)	$1,399	no data

Cost-effectiveness evaluation

Performance per price, higher is better.

Detailed specifications

Core i9-7940X and Xeon E5-2666 V3 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	14 (Tetradeca-Core)	10 (Deca-Core)
Threads	28	20
Base clock speed	3.1 GHz	2.9 GHz
Boost clock speed	4.4 GHz	3.5 GHz
Bus type	DMI 3.0	no data
Bus rate	4 × 8 GT/s	no data
L1 cache	896 KB	64K (per core)
L2 cache	14 MB	256K (per core)
L3 cache	19.25 MB (shared)	25 MB (shared)
Chip lithography	14 nm	22 nm
Die size	484 mm2	356 mm2
Maximum core temperature	102 °C	no data
Number of transistors	no data	2,600 million
64 bit support	+	+
Windows 11 compatibility	+	no data
Unlocked multiplier	+	-

Compatibility

Information on Core i9-7940X and Xeon E5-2666 V3 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 (Uniprocessor)	2
Socket	FCLGA2066	2011-3
Power consumption (TDP)	165 Watt	135 Watt

Technologies and extensions

Technological solutions and additional instructions supported by Core i9-7940X and Xeon E5-2666 V3. You'll probably need this information if you require some particular technology.

Instruction set extensions	Intel® SSE4.1, Intel® SSE4.2, Intel® AVX2, Intel® AVX-512	no data
AES-NI	+	+
AVX	+	+
vPro	no data	+
Enhanced SpeedStep (EIST)	+	+
Turbo Boost Technology	2.0	no data
Hyper-Threading Technology	+	no data
TSX	+	+
Turbo Boost Max 3.0	+	no data

Security technologies

Core i9-7940X and Xeon E5-2666 V3 technologies aimed at improving security, for example, by protecting against hacks.

TXT	no data	+
EDB	+	no data

Virtualization technologies

Virtual machine speed-up technologies supported by Core i9-7940X and Xeon E5-2666 V3 are enumerated here.

VT-d	+	+
VT-x	+	+

Memory specs

Types, maximum amount and channel quantity of RAM supported by Core i9-7940X and Xeon E5-2666 V3. Depending on the motherboard, higher memory frequencies may be supported.

Supported memory types	DDR4-2666	DDR3, DDR4 2133 MHz Quad-channel
Maximum memory size	128 GB	no data
Max memory channels	4	no data
Maximum memory bandwidth	85.33 GB/s	no data

Graphics specifications

General parameters of integrated GPUs, if any.

Integrated graphics card

N/A

no data

Peripherals

Specifications and connection of peripherals supported by Core i9-7940X and Xeon E5-2666 V3.

PCIe version	3.0	3.0
PCI Express lanes	44	40

Synthetic benchmark performance

Various benchmark results of the processors in comparison. Overall score is measured in points in 0-100 range, higher is better.

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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.

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Pros & cons summary

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Performance score	16.65	9.14
Recency	30 May 2017	13 November 2014
Physical cores	14	10
Threads	28	20
Chip lithography	14 nm	22 nm
Power consumption (TDP)	165 Watt	135 Watt

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Should you still have questions on choice between Core i9-7940X and Xeon E5-2666 V3, ask them in Comments section, and we shall answer.

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