i7-975 vs i5-6400

Primary details

Comparing Core i5-6400 and Core i7-975 processor market type (desktop or notebook), architecture, sales start time and price.

Place in the ranking	1551	1833
Place by popularity	not in top-100	not in top-100
Cost-effectiveness evaluation	0.66	0.10
Market segment	Desktop processor	Desktop processor
Series	Intel Core i5	Core i7 (Desktop)
Power efficiency	4.96	1.60
Architecture codename	Skylake (2015−2016)	Bloomfield (2008−2010)
Release date	2 July 2015 (9 years ago)	2 June 2009 (15 years ago)
Launch price (MSRP)	$187	$476

Cost-effectiveness evaluation

Performance per price, higher is better.

i5-6400 has 560% better value for money than i7-975.

Detailed specifications

Core i5-6400 and Core i7-975 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)	4 (Quad-Core)
Threads	4	8
Base clock speed	2.7 GHz	3.33 GHz
Boost clock speed	3.3 GHz	3.6 GHz
Bus type	DMI 3.0	no data
Bus rate	4 × 8 GT/s	1333 MHz
Multiplier	27	no data
L1 cache	64K (per core)	64 KB (per core)
L2 cache	256K (per core)	256 KB (per core)
L3 cache	6 MB (shared)	8 MB (shared)
Chip lithography	14 nm	45 nm
Die size	177 mm2	263 mm2
Maximum case temperature (TCase)	72 °C	68 °C
Number of transistors	no data	731 million
64 bit support	+	+
Windows 11 compatibility	-	-
Unlocked multiplier	-	+

Compatibility

Information on Core i5-6400 and Core i7-975 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
Socket	FCLGA1151	FCLGA1366
Power consumption (TDP)	65 Watt	130 Watt

Technologies and extensions

Technological solutions and additional instructions supported by Core i5-6400 and Core i7-975. You'll probably need this information if you require some particular technology.

Instruction set extensions	Intel® SSE4.1, Intel® SSE4.2, Intel® AVX2	Intel® SSE4.2
AES-NI	+	-
AVX	+	-
vPro	+	no data
Enhanced SpeedStep (EIST)	+	+
Turbo Boost Technology	2.0	1.0
Hyper-Threading Technology	-	+
Idle States	+	+
Thermal Monitoring	+	-
Demand Based Switching	no data	-
PAE	no data	36 Bit

Security technologies

Core i5-6400 and Core i7-975 technologies aimed at improving security, for example, by protecting against hacks.

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

Virtualization technologies

Virtual machine speed-up technologies supported by Core i5-6400 and Core i7-975 are enumerated here.

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

Memory specs

Types, maximum amount and channel quantity of RAM supported by Core i5-6400 and Core i7-975. Depending on the motherboard, higher memory frequencies may be supported.

Supported memory types	DDR3, DDR4	DDR3
Maximum memory size	64 GB	24 GB
Max memory channels	2	3
Maximum memory bandwidth	34.134 GB/s	25.6 GB/s

Graphics specifications

General parameters of integrated GPUs, if any.

Integrated graphics card	Intel HD Graphics 530	N/A
Max video memory	64 GB	no data
Quick Sync Video	+	-
Clear Video	+	no data
Clear Video HD	+	no data
Graphics max frequency	950 MHz	no data
InTru 3D	+	no data

Graphics interfaces

Available interfaces and connections of Core i5-6400 and Core i7-975 integrated GPUs.

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

Graphics image quality

Maximum display resolutions supported by Core i5-6400 and Core i7-975 integrated GPUs, including resolutions over different interfaces.

4K resolution support	+	no data
Max resolution over HDMI 1.4	4096x2304@24Hz	no data
Max resolution over eDP	4096x2304@60Hz	no data
Max resolution over DisplayPort	4096x2304@60Hz	no data
Max resolution over VGA	N/A	no data

Graphics API support

APIs supported by Core i5-6400 and Core i7-975 integrated GPUs, sometimes API versions are included.

DirectX	12	no data
OpenGL	4.5	no data

Peripherals

Specifications and connection of peripherals supported by Core i5-6400 and Core i7-975.

PCIe version	3.0	2.0
PCI Express lanes	16	no data

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	3.41	2.20
Recency	2 July 2015	2 June 2009
Threads	4	8
Chip lithography	14 nm	45 nm
Power consumption (TDP)	65 Watt	130 Watt

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Should you still have questions on choice between Core i5-6400 and Core i7-975, ask them in Comments section, and we shall answer.

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