Core i7-1255U vs Core 2 Quad Q8400s

Primary details

Comparing Core 2 Quad Q8400s and Core i7-1255U processor market type (desktop or notebook), architecture, sales start time and price.

Place in the ranking	not rated	882
Place by popularity	not in top-100	37
Market segment	Desktop processor	Laptop
Series	no data	Intel Alder Lake-M
Power efficiency	no data	53.88
Architecture codename	Yorkfield (2007−2009)	Alder Lake-U (2022)
Release date	19 April 2009 (15 years ago)	23 February 2022 (2 years ago)

Detailed specifications

Core 2 Quad Q8400s and Core i7-1255U 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)	10 (Deca-Core)
Threads	4	12
Base clock speed	2.66 GHz	1.7 GHz
Boost clock speed	0.67 GHz	4.7 GHz
Bus rate	1333 MHz	no data
L1 cache	64 KB (per core)	80K (per core)
L2 cache	4 MB (shared)	1.25 MB (per core)
L3 cache	0 KB	12 MB (shared)
Chip lithography	45 nm	Intel 7 nm
Die size	2x 82 mm2	no data
Maximum core temperature	no data	100 °C
Maximum case temperature (TCase)	76 °C	no data
Number of transistors	456 million	no data
64 bit support	+	+
Windows 11 compatibility	-	+
VID voltage range	0.85V-1.3625V	no data

Compatibility

Information on Core 2 Quad Q8400s and Core i7-1255U 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	FCLGA775,LGA775	FCBGA1744
Power consumption (TDP)	65 Watt	15 Watt

Technologies and extensions

Technological solutions and additional instructions supported by Core 2 Quad Q8400s and Core i7-1255U. You'll probably need this information if you require some particular technology.

Instruction set extensions	no data	Intel® SSE4.1, Intel® SSE4.2, Intel® AVX2
AES-NI	-	+
FMA	-	+
AVX	-	+
Enhanced SpeedStep (EIST)	+	+
Speed Shift	no data	+
Turbo Boost Technology	-	no data
Hyper-Threading Technology	-	+
TSX	-	+
Idle States	+	no data
Thermal Monitoring	+	+
Flex Memory Access	no data	+
Demand Based Switching	-	no data
Deep Learning Boost	-	+

Security technologies

Core 2 Quad Q8400s and Core i7-1255U technologies aimed at improving security, for example, by protecting against hacks.

TXT	-	+
EDB	+	+
Secure Key	no data	+
OS Guard	no data	+

Virtualization technologies

Virtual machine speed-up technologies supported by Core 2 Quad Q8400s and Core i7-1255U are enumerated here.

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

Memory specs

Types, maximum amount and channel quantity of RAM supported by Core 2 Quad Q8400s and Core i7-1255U. Depending on the motherboard, higher memory frequencies may be supported.

Supported memory types	DDR1, DDR2, DDR3	DDR4, DDR5
Maximum memory size	no data	64 GB
Max memory channels	no data	2

Graphics specifications

General parameters of integrated GPUs, if any.

Integrated graphics card	On certain motherboards (Chipset feature)	Intel® Iris® Xe Graphics eligible
Quick Sync Video	-	+
Graphics max frequency	no data	1.25 GHz
Execution Units	no data	96

Graphics interfaces

Available interfaces and connections of Core 2 Quad Q8400s and Core i7-1255U integrated GPUs.

Number of displays supported

no data

4

Graphics image quality

Maximum display resolutions supported by Core 2 Quad Q8400s and Core i7-1255U integrated GPUs, including resolutions over different interfaces.

Max resolution over HDMI 1.4	no data	4096 x 2304 @ 60Hz
Max resolution over eDP	no data	4096 x 2304 @ 120Hz
Max resolution over DisplayPort	no data	7680 x 4320 @ 60Hz

Graphics API support

APIs supported by Core 2 Quad Q8400s and Core i7-1255U integrated GPUs, sometimes API versions are included.

DirectX	no data	12.1
OpenGL	no data	4.6

Peripherals

Specifications and connection of peripherals supported by Core 2 Quad Q8400s and Core i7-1255U.

PCIe version	2.0	4.0
PCI Express lanes	no data	20

Pros & cons summary

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Recency	19 April 2009	23 February 2022
Physical cores	4	10
Threads	4	12
Power consumption (TDP)	65 Watt	15 Watt

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Should you still have questions on choice between Core 2 Quad Q8400s and Core i7-1255U, ask them in Comments section, and we shall answer.

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