Core i5-8400B vs Core i5-8257U

Primary details

Comparing Core i5-8257U and Core i5-8400B processor market type (desktop or notebook), architecture, sales start time and price.

Place in performance ranking	1183	not rated
Place by popularity	not in top-100	not in top-100
Market segment	Laptop	Laptop
Series	Intel Core i5	Intel Core i5
Architecture codename	Coffee Lake-U (2018−2019)	Coffee Lake (2017−2019)
Release date	10 July 2019 (4 years ago)	2 April 2018 (6 years ago)
Launch price (MSRP)	no data	$182
Current price	no data	$54 (0.3x MSRP)

Detailed specifications

Core i5-8257U and Core i5-8400B 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	6
Base clock speed	1.4 GHz	2.8 GHz
Boost clock speed	3.9 GHz	4 GHz
Bus support	no data	4 × 8 GT/s
L1 cache	256 KB	384 KB
L2 cache	1 MB	1.5 MB
L3 cache	6 MB	9 MB
Chip lithography	14 nm	14 nm
Die size	no data	126 mm2
Maximum core temperature	100 °C	100 °C
64 bit support	+	+
Windows 11 compatibility	+	+
Unlocked multiplier	No	No

Compatibility

Information on Core i5-8257U and Core i5-8400B 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	1
Socket	FCBGA1528	FCBGA1440
Power consumption (TDP)	15 Watt	65 Watt

Technologies and extensions

Technological solutions and additional instructions supported by Core i5-8257U and Core i5-8400B. 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	+	+
Enhanced SpeedStep (EIST)	+	+
eDRAM	128 MB	no data
Speed Shift	+	no data
My WiFi	+	no data
Turbo Boost Technology	2.0	2.0
Hyper-Threading Technology	+	-
TSX	-	-
Idle States	+	+
Thermal Monitoring	+	+
Flex Memory Access	+	no data
SIPP	-	-
Status	Discontinued	Discontinued

Security technologies

Core i5-8257U and Core i5-8400B 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 i5-8257U and Core i5-8400B are enumerated here.

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

Memory specs

Types, maximum amount and channel quantity of RAM supported by Core i5-8257U and Core i5-8400B. Depending on the motherboard, higher memory frequencies may be supported.

Supported memory types	DDR4	DDR4-2666
Maximum memory size	32 GB	64 GB
Max memory channels	2	2
Maximum memory bandwidth	37.5 GB/s	42.671 GB/s
ECC memory support	-	-

Graphics specifications

General parameters of integrated GPUs, if any.

Integrated graphics card Compare	Intel Iris Plus Graphics 645	Intel UHD Graphics 630
Max video memory	32 GB	64 GB
Quick Sync Video	+	+
Clear Video	+	+
Clear Video HD	+	+
Graphics max frequency	1.05 GHz	1.05 GHz
InTru 3D	+	+

Graphics interfaces

Available interfaces and connections of Core i5-8257U and Core i5-8400B integrated GPUs.

Number of displays supported	3	3
eDP	+	no data
DisplayPort	+	no data
HDMI	+	no data
DVI	+	no data

Graphics image quality

Maximum display resolutions supported by Core i5-8257U and Core i5-8400B integrated GPUs, including resolutions over different interfaces.

4K resolution support	+	+
Max resolution over HDMI 1.4	4096x2304@30Hz	4096x2304@30Hz
Max resolution over eDP	4096x2304@60Hz	4096x2304@60Hz
Max resolution over DisplayPort	4096x2304@60Hz	4096x2304@60Hz

Graphics API support

APIs supported by Core i5-8257U and Core i5-8400B integrated GPUs, sometimes API versions are included.

DirectX	12	12
OpenGL	4.5	4.5

Peripherals

Specifications and connection of peripherals supported by Core i5-8257U and Core i5-8400B.

PCIe version	3.0	3.0
PCI Express lanes	16	16

Pros & cons summary

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Integrated graphics card	3.99	3.09
Recency	10 July 2019	2 April 2018
Physical cores	4	6
Threads	8	6
Power consumption (TDP)	15 Watt	65 Watt

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Should you still have questions on choice between Core i5-8257U and Core i5-8400B, ask them in Comments section, and we shall answer.

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