Quick Verdict
A highly efficient and popular 15W processor that powers a vast majority of mid-range premium ultrabooks, offering great daily responsiveness.
Overview
Launch
2022
Status
ActiveGeneration
12th Generation
Market
Mobile
The Intel Core i7-1255U is a 15W mobile processor featuring a 10-core hybrid design, tailored for standard ultrabooks balancing performance and battery life.
The Intel Core i7-1255U is the volume leader for 12th Gen i7 ultrabooks. Operating at 15W base power with a 55W turbo, it balances thermal constraints with performance. The 2 P-cores and 8 E-cores handle everyday multitasking flawlessly.
With support for both DDR4 and DDR5 memory, it is a versatile chip found in a wide variety of modern laptops.
Specifications
Performance
Highly responsive for daily office tasks, with plenty of E-cores to keep background apps from slowing down the system.
Good for light Docker containers, but 2 P-cores limit performance when running full Windows VMs.
Can run esports games like League of Legends smoothly, but struggles with modern AAA titles on integrated graphics.
Excellent power management ensures long battery life during typical office use.
- •Iris Xe 96EU handles 1080p low settings for older games
- •Throttles under sustained 3D loads
- •Best paired with a discrete GPU for serious gaming
- •No NPU
- •AI workloads handled by CPU/GPU
Architecture
10 nm
Process Node
Alder Lake-U
Codename
10C / 12T
Core Config
12 MB
L3 Cache
55 W
TDP
Architecture Overview
Alder Lake-U scales efficiently at 15W, using Intel's Thread Director to manage the 2 P-cores and 8 E-cores.
CPU Design
The 2 P-cores reach 4.7 GHz for burst performance, while 8 E-cores handle multitasking, totaling 12 threads.
Memory Subsystem
Supports an incredibly wide range of memory (DDR4, DDR5, LPDDR4X, LPDDR5) for maximum OEM flexibility.
PCIe & I/O
Provides 20 lanes of PCIe 4.0 for direct connection to high-speed storage and docks.
Overclocking
Locked multiplier; tuning is limited to OEM power profile adjustments.
- Added 8 E-cores over the 4-core 11th Gen
- Improved idle power consumption
- Support for DDR5 and LPDDR5
Key Highlights
- Excellent performance-per-watt
- Very flexible memory support
- Good single-core burst performance
- Plenty of PCIe lanes for an ultrabook chip
- Reliable Iris Xe integrated graphics
- Only 2 P-cores limit heavy multi-threading
- Soldered to the motherboard
- Can get warm during 55W turbo bursts
- Not suitable for gaming without a discrete GPU
History
The Core i7-1255U launched as the mainstream 15W i7 option for the 2022 laptop market. It effectively replaced the highly successful i7-1165G7. The most significant change was the transition from a 4-core monolithic design to a 10-core hybrid design.
This drastically improved multitasking capabilities, allowing ultrabooks to handle heavy browser loads and background applications without slowing down.</br>This processor became ubiquitous in the 2022-2023 laptop market, appearing in everything from mid-range Inspirons to premium ZenBooks. Its widespread adoption was due to its perfect balance of cost, performance, and power efficiency.
By supporting both older DDR4 and newer DDR5 memory, Intel allowed manufacturers to slowly transition their product lines without needing to redesign motherboards immediately, making the 1255U a cornerstone chip of the 12th Gen mobile rollout.
Improvements over Previous Generation
- Added 8 E-cores over the 4-core 11th Gen
- Improved idle power consumption
- Support for DDR5 and LPDDR5
Alternatives & Competitors
Should You Buy It?
Recommended for the right buyer
Buying a standard ultrabook for school or office work where you need strong battery life and snappy daily performance.
Avoid if…
- You need to run heavy rendering software
- You plan to play demanding games
- You require an upgradeable platform
Use Cases
Interesting Facts
The Core i7-1255U has a base clock of 1.7 GHz.
The specific part number is SRLFP.
It supports four different memory types: DDR4, DDR5, LPDDR4X, and LPDDR5.
The base TDP is 15W with a 55W turbo ceiling.
It uses the Intel BGA 1744 socket.
The E-cores run at a base frequency of 1200 MHz.
It was released on February 23rd, 2022.
The L3 cache is 12 MB.
The base multiplier is 17.0x.
The integrated graphics boost up to 1250 MHz.
People Also Ask
What is the TDP of the Intel Core i7-1255U?
The base TDP is 15 watts, and the maximum turbo power is 55 watts.
Is the i7-1255U good for gaming?
It is okay for light 1080p gaming on low settings, but not recommended for serious gaming.
What is the difference between i7-1255U and i7-1265U?
The i7-1265U has slightly higher P-core and E-core base clocks, as well as a higher max turbo frequency.
Does the Core i7-1255U support DDR5?
Yes, it supports DDR5-4800, as well as DDR4, LPDDR4X, and LPDDR5.
How many cores does the i7-1255U have?
It has 10 cores: 2 Performance cores and 8 Efficient cores.
Can the i7-1255U be overclocked?
No, the multiplier is locked.
What socket does the i7-1255U use?
It uses the Intel BGA 1744 socket.
Does the i7-1255U have good battery life?
Yes, the 15W TDP provides excellent battery life in modern ultrabooks.
When was the i7-1255U released?
It was released on February 23rd, 2022.
Is the i7-1255U good for video editing?
It handles 1080p video editing well, but 4K editing will cause thermal throttling.
Frequently Asked Questions
Does the Core i7-1255U support ECC memory?
No, it does not support ECC memory.
What is the max turbo frequency of the i7-1255U?
The maximum turbo frequency is 4.7 GHz.
How much L3 cache does the i7-1255U have?
It has 12 MB of L3 cache.
What is the base clock of the i7-1255U E-cores?
The E-cores have a base clock of 1.2 GHz.
What PCIe version does the i7-1255U support?
It supports PCIe 4.0 with 20 lanes.
Does the i7-1255U support virtualization?
Yes, it supports VT-x and VT-d.
What is the part number for the i7-1255U?
The part number is SRLFP.
What is the maximum operating temperature of the i7-1255U?
The maximum junction temperature is 100°C.
What memory speeds does the i7-1255U support?
It supports DDR4-3200, DDR5-4800, LPDDR4X-4267, and LPDDR5-5200.
Is the i7-1255U good for students?
Yes, it is an excellent processor for students due to its balance of performance and battery life.