i5-8400T vs i9-9900K

Primary details

Comparing Core i9-9900K and Core i5-8400T processor market type (desktop or notebook), architecture, sales start time and price.

Place in the ranking	686	1282
Place by popularity	not in top-100	not in top-100
Cost-effectiveness evaluation	7.93	4.94
Market segment	Desktop processor	Desktop processor
Series	Core i9 (Desktop)	Intel Core i5
Power efficiency	11.45	12.69
Architecture codename	Coffee Lake-R (2018−2019)	Coffee Lake (2017−2019)
Release date	19 October 2018 (6 years ago)	2 April 2018 (6 years ago)
Launch price (MSRP)	$488	$182

Cost-effectiveness evaluation

Performance per price, higher is better.

i9-9900K has 61% better value for money than i5-8400T.

Detailed specifications

Core i9-9900K and Core i5-8400T 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	8 (Octa-Core)	6 (Hexa-Core)
Threads	16	6
Base clock speed	3.6 GHz	1.7 GHz
Boost clock speed	5 GHz	3.3 GHz
Bus type	DMI 3.0	DMI 3.0
Bus rate	4 × 8 GT/s	4 × 8 GT/s
Multiplier	no data	17
L1 cache	64K (per core)	64K (per core)
L2 cache	256K (per core)	256K (per core)
L3 cache	16 MB (shared)	9 MB (shared)
Chip lithography	14 nm	14 nm
Die size	178 mm2	149 mm2
Maximum core temperature	100 °C	100 °C
Maximum case temperature (TCase)	72 °C	72 °C
64 bit support	+	+
Windows 11 compatibility	+	+
Unlocked multiplier	+	-

Compatibility

Information on Core i9-9900K and Core i5-8400T 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	LGA-1151	FCLGA1151
Power consumption (TDP)	95 Watt	35 Watt

Technologies and extensions

Technological solutions and additional instructions supported by Core i9-9900K and Core i5-8400T. You'll probably need this information if you require some particular technology.

Instruction set extensions	Intel® SSE4.1, Intel® SSE4.2, Intel® AVX2	Intel® SSE4.1, Intel® SSE4.2, Intel® AVX2
AES-NI	+	+
AVX	+	+
vPro	+	no data
Enhanced SpeedStep (EIST)	+	+
Turbo Boost Technology	2.0	2.0
Hyper-Threading Technology	+	-
TSX	+	-
Idle States	+	+
Thermal Monitoring	+	+
SIPP	+	-

Security technologies

Core i9-9900K and Core i5-8400T technologies aimed at improving security, for example, by protecting against hacks.

TXT	+	-
EDB	+	+
Secure Key	+	+
MPX	+	+
Identity Protection	+	+
SGX	Yes with Intel® ME	Yes with Intel® ME
OS Guard	+	+

Virtualization technologies

Virtual machine speed-up technologies supported by Core i9-9900K and Core i5-8400T are enumerated here.

AMD-V	+	-
VT-d	+	+
VT-x	+	+
EPT	+	+

Memory specs

Types, maximum amount and channel quantity of RAM supported by Core i9-9900K and Core i5-8400T. Depending on the motherboard, higher memory frequencies may be supported.

Supported memory types	DDR4	DDR4-2666
Maximum memory size	128 GB	128 GB
Max memory channels	2	2
Maximum memory bandwidth	44.668 GB/s	42.671 GB/s

Graphics specifications

General parameters of integrated GPUs, if any.

Integrated graphics card	Intel UHD Graphics 630	Intel UHD Graphics 630
Max video memory	64 GB	64 GB
Quick Sync Video	+	+
Clear Video	+	+
Clear Video HD	+	+
Graphics max frequency	1.2 GHz	1.05 GHz
InTru 3D	+	+

Graphics interfaces

Available interfaces and connections of Core i9-9900K and Core i5-8400T integrated GPUs.

Number of displays supported

3

3

Graphics image quality

Maximum display resolutions supported by Core i9-9900K and Core i5-8400T integrated GPUs, including resolutions over different interfaces.

4K resolution support	+	+
Max resolution over HDMI 1.4	4096 x 2304@24Hz	4096x2304@24Hz
Max resolution over eDP	4096 x 2304@60Hz	4096x2304@60Hz
Max resolution over DisplayPort	4096 x 2304@60Hz	4096x2304@60Hz

Graphics API support

APIs supported by Core i9-9900K and Core i5-8400T integrated GPUs, sometimes API versions are included.

DirectX	12	12
OpenGL	4.5	4.5

Peripherals

Specifications and connection of peripherals supported by Core i9-9900K and Core i5-8400T.

PCIe version	3.0	3.0
PCI Express lanes	16	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	11.49	4.69
Recency	19 October 2018	2 April 2018
Physical cores	8	6
Threads	16	6
Power consumption (TDP)	95 Watt	35 Watt

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Should you still have questions on choice between Core i9-9900K and Core i5-8400T, ask them in Comments section, and we shall answer.

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