i7-1255U vs i9-9900X

Primary details

Comparing Core i9-9900X and Core i7-1255U processor market type (desktop or notebook), architecture, sales start time and price.

Place in the ranking	533	885
Place by popularity	not in top-100	37
Cost-effectiveness evaluation	4.93	no data
Market segment	Desktop processor	Laptop
Series	Intel Core i9	Intel Alder Lake-M
Power efficiency	7.89	53.88
Architecture codename	Skylake (server) (2017−2018)	Alder Lake-U (2022)
Release date	19 October 2018 (6 years ago)	23 February 2022 (2 years ago)
Launch price (MSRP)	$989	no data

Cost-effectiveness evaluation

Performance per price, higher is better.

Detailed specifications

Core i9-9900X 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	10 (Deca-Core)	10 (Deca-Core)
Threads	20	12
Base clock speed	3.5 GHz	1.7 GHz
Boost clock speed	4.5 GHz	4.7 GHz
Bus type	DMI 3.0	no data
Bus rate	4 × 8 GT/s	no data
Multiplier	35	no data
L1 cache	64 KB (per core)	80K (per core)
L2 cache	1 MB (per core)	1.25 MB (per core)
L3 cache	19.25 MB (shared)	12 MB (shared)
Chip lithography	14 nm	Intel 7 nm
Maximum core temperature	92 °C	100 °C
Maximum case temperature (TCase)	72 °C	no data
64 bit support	+	+
Windows 11 compatibility	+	+
Unlocked multiplier	+	-

Compatibility

Information on Core i9-9900X 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 (Uniprocessor)	1
Socket	FCLGA2066	FCBGA1744
Power consumption (TDP)	165 Watt	15 Watt

Technologies and extensions

Technological solutions and additional instructions supported by Core i9-9900X and Core i7-1255U. 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	+	+
FMA	-	+
AVX	+	+
Enhanced SpeedStep (EIST)	+	+
Speed Shift	no data	+
Turbo Boost Technology	2.0	no data
Hyper-Threading Technology	+	+
TSX	+	+
Thermal Monitoring	-	+
Flex Memory Access	no data	+
Turbo Boost Max 3.0	+	no data
Deep Learning Boost	-	+

Security technologies

Core i9-9900X and Core i7-1255U technologies aimed at improving security, for example, by protecting against hacks.

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

Virtualization technologies

Virtual machine speed-up technologies supported by Core i9-9900X and Core i7-1255U are enumerated here.

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

Memory specs

Types, maximum amount and channel quantity of RAM supported by Core i9-9900X and Core i7-1255U. Depending on the motherboard, higher memory frequencies may be supported.

Supported memory types	DDR4-2666	DDR4, DDR5
Maximum memory size	128 GB	64 GB
Max memory channels	4	2
Maximum memory bandwidth	85.33 GB/s	no data

Graphics specifications

General parameters of integrated GPUs, if any.

Integrated graphics card	N/A	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 i9-9900X and Core i7-1255U integrated GPUs.

Number of displays supported

no data

4

Graphics image quality

Maximum display resolutions supported by Core i9-9900X 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 i9-9900X 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 i9-9900X and Core i7-1255U.

PCIe version	3.0	4.0
PCI Express lanes	44	20

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	13.76	8.54
Recency	19 October 2018	23 February 2022
Threads	20	12
Power consumption (TDP)	165 Watt	15 Watt

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Should you still have questions on choice between Core i9-9900X and Core i7-1255U, ask them in Comments section, and we shall answer.

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