GuidesComparisonsCore i7-1255U Vs Core i5-1235U: Detailed Comparison

Core i7-1255U Vs Core i5-1235U: Detailed Comparison

In this article, we will be taking a closer look at the price, specifications and performance of the Core i7-1255U and Core i5-1235U

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At launch, Intel’s Alder Lake CPUs became the primary choice of PC gamers and casual consumers alike, as they blew AMD’s Ryzen 5000 CPUs out of the water. Today, I’ll compare two mobile CPUs from this Alder Lake lineup in Core i7-1255U vs Core i5-1235U. Read on to find which CPU is worth the dollar.

Key Takeaways

  • The Core i7-1255U proved 12.4% faster in multi-core applications and 5.2% in single-core applications than the Core i5-1235U.
  • Regarding power consumption, the Core i7-1255U consumed 5.9% more power under load than the Core i5-1235U.
  • Price-wise, Core i7-1255U laptops cost between $419 and $2168, while Core i5-1235U laptops range from $289 to $1199.
  • Talking value, the Core i5-1235U is much better as it costs much less for a small performance difference.

Comparison Table

Mobile CPU Core i7-1255U Core i5-1235U
Architecture Hybrid Core Hybrid Core
Codename Alder Lake-U Alder Lake-U
Instruction Set x86-64 x86-64
Processing Node Intel 7 (10nm) Intel 7 (10nm)
Socket BGA-1744 BGA-1744
No. of Cores 10 (2P + 8E) 10 (2P + 8E)
No. of Threads 12 (4 + 8) 12 (4 + 8)
Base Clock
  • 1.7GHz (P-cores)
  • 1.2GHz (E-cores)
  • 1.3GHz (P-cores)
  • 0.9GHz (E-cores)
Boost Clock
  • 4.7GHz (P-cores)
  • 3.5GHz (E-cores)
  • 4.4GHz (P-cores)
  • 3.3GHz (E-cores)
L1 Cache 80KB per core 80KB per core
L2 Cache 1280KB per core 1280KB per core
L3 Cache 12MB (shared) 18MB (shared)
Memory Support
  • DDR5 up to 4800 MT/s
  • DDR4 up to 3200 MT/s
  •   LPDDR5 up to 5200 MT/s
  •    LPDDR4x up to 4267 MT/s
  •  DDR5 up to 4800 MT/s
  • DDR4 up to 3200 MT/s
  •   LPDDR5 up to 5200 MT/s
  •    LPDDR4x up to 4267 MT/s
Memory Size Up to 64GB Up to 64GB
PCIe Revision 4.0 4.0 
No. of PCIe Lanes 20 20
Overclocking Support No No
Integrated Graphics Intel Iris Xe graphics Intel Iris Xe Graphics
GPU Base Clock 300MHz 300MHz
GPU Boost Clock 1250MHz 1200MHz
No. of Shaders 768 640
No. of TMUs 48 40
No. of ROPs 24 20
No. of Execution Units  96 80
iGPU Theoretical 
Performance
1.69 TFLOPs 1.41 TFLOPs
Total Graphics Power 15W 15W
CPU Max Operating Temperature  100°C  100°C
CPU Base Power 12-15W (configurable) 12-15W (configurable)
CPU Boost Power 55W 55W
Price Range (July 2023) $419 to $2068 $289-$1199
Launch Date February 23, 2022 February 23, 2022

Architectural Differences

  1. Clock SpeedsThe Core i7-1255U boasts faster speeds, clocking 1.7GHz on the P-cores and 1.2GHz on the E-cores at the base. In contrast, the Core i5-1235U P-cores run at 1.3GHz while the E-cores run at 0.9GHz regarding base frequencies. As for boost speeds, the Core i7-1255U clocks 4.7GHz (P-cores) and 3.5GHz (E-cores) over 4.4GHz (P-cores) and 3.3GHz (E-cores) of the Core i5-1235U.
  2. iGPU: The Core i7-1255U adds 50MHz to the boost core clock speeds. In addition, it beats the Core i5-1235U regarding the number of core rendering units, including shading units, TMUs, ROPs, and EUs. All in all, this gives it better performance, at 1.69 TFLOPs over 1.41 TFLOPs of the Core i5-1235U.

Also Read: Core i7-1255U Vs Core i5-1335U

Core i7-1255U Vs Core i5-1235U: Performance Benchmarks

Cinebench R23

Cinebench R23 multi-core and single-core
Cinebench R23 (Image by Tech4Gamers)
  • Kicking things off with the Cinebench R23 multi-core test, the Core i7-1255U scores 8342 points. In comparison, the Core i5-1235U trailed with 6618 points.
  • In the single-core test, the Core i7-1255U has a very narrow lead with 1665 points over 1654 of the Core i5-1235U.

Geekbench 5

Geekbench 5 multi-core and single-core 
Geekbench 5 (Image by Tech4Gamers)
  • Moving on to Geekbench 5, the Core i7-1255U managed 7402 points in the multi-core test. In reply, the Intel Core i5-1235U’s figures read 6333 points.
  • Regarding the single-core result, the Core i7-1255U scored 1655 points over 1580 points of the Core i5-1235U. 

Geekbench 6

Geekbench 6 multi-core and single-core 
Geekbench 6 (Image by Tech4Gamers)
  • The next benchmark is Geekbench 6, where the Intel Core i7-1255U racked up 6662 multi-core points. Its Core i5 competitor scored 5677 points, trailing by 17.3%.
  • As for the single-core scores, the Core i7-1255U recorded 1993 points, while the Core i5-1235U recorded 1688 points

Related: Core i7-12700H Vs Core i7-1255U

Passmark

Passmark multi-core and single-core 
Passmark (Image by Tech4Gamers)
  • In Passmark, the Core i7-1255U bagged 13905 points, leading the Core i5-1235U (3334 points) by 1.7%.
  • The Core i7-1255U (3382 points) also has an insignificant lead in the single-core test, at 1.4%.

Summing Up The Multi-Core And Single-Core Performance

Before reviewing the remaining benchmarks, here’s a look at the average multi-core and single-core scores across the four tests. 

Average multi-core and single-core scores
Overall performance (Image by Tech4Gamers) 
  • Multi-core Performance: The Core i7-1255U notched up 9077 points on average compared to 8073 points the Intel Core i5-1235U scored. In conclusion, the Core i7-1255U is, on average, 12.4% faster than the Core i5-1235U in multi-core applications.
  • Single-core Performance: The Core i7-1255U averaged 2173 points in single-core applications. Meanwhile, the Core i5-1235U’s average is 2064 points. Thus, the Core i7-1255U leads the Core i5-1235U by 5.2% in single-core performance.

Also Check: Core i7-1255U Vs Core i7-1165G7

3DMark Time Spy CPU Benchmark

3DMark Time Spy CPU benchmark
3DMark Time Spy (Image by Tech4Gamers)
  • The Intel Core i7-1255U scored 6140 points in this test over 5647 of the Core i5-1235U. 
  • Here, the Core i7-1255U has an 8.7% lead over the Core i5-1235U.

Blender 3.3 Classroom

Blender 3.3 Classroom render 
Blender 3.3 Classroom (Image by Tech4Gamers)
  • In Blender 3.3, the Core i7-1255U leads again, rendering the scene in 723 seconds. Conversely, the Core i5-1235U took 846 seconds to render the scene.
  • The Core i7-1255U rendered the scene 17% faster than the Intel Core i5-1235U.

Similar Comparison: Intel Core i5-1235U Vs AMD Ryzen 5 7520U

Power Consumption

Both CPUs have the same base (12-15W) and boost TDP ratings (55W). Let’s see if there is any difference in their power consumption numbers.

Power consumption, stress and idle 
Power consumption (Image by Tech4Gamers) 
  • Idle power consumption: Both CPUs averaged 6.2 watts of power draw when idle.
  • Load power consumption: Under load (using the Cinebench R15 multi-core test), the Core i7-1255U averaged 55.6 watts of power consumption. In response, the Core i5-1235U averaged 52.5 watts. So, the Core i5-1235U is 5.9%, approximately more power-efficient under loads.

Related: Core i5 1235U Vs Ryzen 5 7530U

Laptop Prices 

Let’s look at the prices for Core i7-1255U and Core i7-1235U laptops.

Note: The prices have been estimated from Amazon US and are valid as of July 2023

  • Core i7-1255U: Entry-level laptops using this mobile CPU cost at least $419, while the best-selling options are in the $619-$1100 price bracket. The most premium Core i7-1255U laptops can cost up to $2068.
  • Core i5-1235U: The Core i5-1235U laptops start from $289, and the best-selling laptops can cost anywhere between $479 and $799. Additionally, the most expensive Core i5-1235U laptop can set you back by $1199.

Also Read: How Much Is My Gaming PC Worth?

Better Value: Core i7-1255U Vs Core i5-1235U

To summarize the performance and price discussion, let’s figure out which CPU has more value for money. The Core i7-1255U performed 12.4% and 5.2% faster in the multi-core and single-core tests, respectively. It also outperformed the Core i5-1235U in the Blender and 3DMark Time Spy benchmarks.

When it comes to the prices, though, you’ll be paying 44% more for an entry-level Core i7-1255U laptop compared to a Core i5-1235U laptop. The price difference is much greater than the performance difference.

Also, the Core i7-1255U consumed 5.9% more power during the Cinebench R15 stress test. 

All these factors favor the Core i5-1235U, giving it much more value than the Intel Core i7-1255U.

Which One To Go For? 

Let’s conclude this Core i7-1255U vs Core i5-1235U comparison.

While the Core i7-1255U certainly performs better in all the benchmarks, it’s the Core i5-1235U that has more value for money. The two laptop CPUs hardly differ in specifications, yet the Core i7-1255U laptops cost significantly more than the Core i5-1255U ones. 

If you only care about performance, the Core i7-1255U is the better choice, but if you want to save money while sacrificing little performance, the Core i5-1235U is the CPU for you. 

Also Check: Core i7-1255U Vs Core i5-1335U

Pros And Cons 

CPU Pros Cons
Core i7-1255U
  • Better overall performance
  • Faster iGPU
  • Better clock speeds
  • More power-consuming
  • Relatively bad value
Core i5-1235U
  • Much better value 
  • More power efficient
  • Lags behind in overall
    performance

Pros And Cons: Core i7-1255U vs Core i5-1235U

Frequently Asked Questions

Does the Core i7-1255U have more cores than the Core i5-1235U?

No. You wouldn’t be wrong for thinking the Core i7 CPU has more cores, but both CPUs share the same 10-core count in this case.

Is the Core i5-1235U more power-efficient than the Core i7-1255U?

While both CPUs share the same base and boost TDP ratings, the Core i5-1235U proved 5.9% more power efficient during the Cinebench R15 stress test.

What are the architectural differences between the Core i5-1235U and Core i7-1255U?

The Core i7-1255U possesses faster base and boost clock speeds and a more powerful iGPU than the Core i5-1235U.

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