i9-9900KF vs i9-9940X

Primary details

Comparing Core i9-9940X and Core i9-9900KF processor market type (desktop or notebook), architecture, sales start time and price.

Place in the ranking	356	688
Place by popularity	not in top-100	not in top-100
Cost-effectiveness evaluation	5.29	8.45
Market segment	Desktop processor	Desktop processor
Series	Intel Core i9	Intel Core i9
Power efficiency	10.11	11.43
Architecture codename	Skylake (server) (2017−2018)	Coffee Lake-R (2018−2019)
Release date	19 October 2018 (6 years ago)	8 January 2019 (5 years ago)
Launch price (MSRP)	$1,387	$488

Cost-effectiveness evaluation

Performance per price, higher is better.

i9-9900KF has 60% better value for money than i9-9940X.

Detailed specifications

Core i9-9940X and Core i9-9900KF 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)	8 (Octa-Core)
Threads	28	16
Base clock speed	3.3 GHz	3.6 GHz
Boost clock speed	4.5 GHz	5 GHz
Bus type	DMI 3.0	DMI 3.0
Bus rate	4 × 8 GT/s	4 × 8 GT/s
Multiplier	33	no data
L1 cache	64 KB (per core)	64K (per core)
L2 cache	1 MB (per core)	256K (per core)
L3 cache	19.25 MB (shared)	16 MB (shared)
Chip lithography	14 nm	14 nm
Die size	484 mm2	no data
Maximum core temperature	88 °C	100 °C
Maximum case temperature (TCase)	no data	72 °C
64 bit support	+	+
Windows 11 compatibility	+	+
Unlocked multiplier	+	+

Compatibility

Information on Core i9-9940X and Core i9-9900KF 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)	1 (Uniprocessor)
Socket	FCLGA2066	FCLGA1151
Power consumption (TDP)	165 Watt	95 Watt

Technologies and extensions

Technological solutions and additional instructions supported by Core i9-9940X and Core i9-9900KF. 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	Intel® SSE4.1, Intel® SSE4.2, Intel® AVX2
AES-NI	+	+
AVX	+	+
Enhanced SpeedStep (EIST)	+	+
Turbo Boost Technology	2.0	2.0
Hyper-Threading Technology	+	+
TSX	+	+
Idle States	no data	+
Thermal Monitoring	-	+
Turbo Boost Max 3.0	+	no data

Security technologies

Core i9-9940X and Core i9-9900KF technologies aimed at improving security, for example, by protecting against hacks.

TXT	no data	-
EDB	+	+
Secure Key	no data	+
MPX	-	+
Identity Protection	-	+
SGX	no data	Yes with Intel® ME
OS Guard	no data	+

Virtualization technologies

Virtual machine speed-up technologies supported by Core i9-9940X and Core i9-9900KF are enumerated here.

VT-d	+	+
VT-x	+	+
EPT	no data	+

Memory specs

Types, maximum amount and channel quantity of RAM supported by Core i9-9940X and Core i9-9900KF. Depending on the motherboard, higher memory frequencies may be supported.

Supported memory types	DDR4-2666	DDR4-2666
Maximum memory size	128 GB	128 GB
Max memory channels	4	2
Maximum memory bandwidth	85.33 GB/s	42.671 GB/s

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 i9-9940X and Core i9-9900KF.

PCIe version	3.0	3.0
PCI Express lanes	44	16

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	17.62	11.47
Recency	19 October 2018	8 January 2019
Physical cores	14	8
Threads	28	16
Power consumption (TDP)	165 Watt	95 Watt

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Should you still have questions on choice between Core i9-9940X and Core i9-9900KF, ask them in Comments section, and we shall answer.

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