Intel Core i5-1235U vs Intel Core i7-1260U Comparison

The Intel Core i7-1260U and Intel Core i5-1235U are both Alder Lake-U mobile processors, but benchmark data shows they are not interchangeable. The i7-1260U wins 14 of 19 head-to-head tests, while the i5-1235U takes 5. However, the nature of those wins is decisive: the i7 dominates in single-threaded and mixed workloads, while the i5 pulls ahead in specific math-heavy and prime-number tests. The average benchmark score slightly favors the i5-1235U at 16770 versus 16320 for the i7, but this aggregate figure masks the i7’s clear superiority in most real-world responsive tasks.

Head-to-Head Benchmarks

The largest margin in the entire comparison belongs to the i5-1235U in the PassMark find prime numbers test, where it scores 954 against the i7’s 67, a staggering 93% advantage. This is an extreme outlier, not representative of typical performance. The i7-1260U counters with a 59.1% win in Cinebench R15 single-core, scoring 219.5 versus 138. That R15 single-core gap is the second-largest delta in the dataset, indicating the i7’s superior per-thread execution capability.

In multi-core Cinebench tests, the results are contradictory. The i7 wins Cinebench R15 multi-core (1203 vs 985, +22.1%) and Cinebench R20 multi-core (4736 vs 4105, +15.4%). Yet in Cinebench R23 multi-core, the i5 flips the script with 9774 versus 7912.5, a 19% advantage for the i5. This reversal suggests that the longer R23 render workload favors the i5’s sustained power delivery, despite its lower peak single-core performance.

The Geekbench suite is an unambiguous win for the i7. In single-core, the i7 scores 1936 against 1609, a 20.3% lead. Multi-core shows a similar story: 6320 versus 5308, a 19.1% advantage. These results align with the Cinebench R15 and R20 data, reinforcing that the i7’s core architecture is faster in most standard workloads.

PassMark tests reveal a split. The i7 wins data compression (152217 vs 147450, +3.2%), data encryption (9480 vs 9347, +1.4%), extended instructions (8280 vs 8176, +1.3%), multithread (14011 vs 12923, +8.4%), physics (1046 vs 686, +52.5%), and single-thread (3153 vs 3151, +0.1%). The i5 wins floating point math (43303 vs 31456, -27.4% for the i7), integer math (48553 vs 45887, -5.5%), and random string sorting (17050 vs 16726, -1.9%). The physics test is particularly telling: the i7 leads by over half, indicating far better simulation and constraint-solving performance.

Where Each One Wins

The i7-1260U is the clear choice for single-threaded responsiveness and general productivity. Its wins in Cinebench R15 single-core, R20 single-core, R23 single-core, and Geekbench single-core are consistent, with deltas ranging from 15.4% to 59.1%. This makes it better suited for applications that rely on fast per-core execution, such as office suites, web browsing, and light coding. The i7 also dominates in physics simulation, scoring 1046 versus 686 (+52.5%), which is critical for engineering software and older games that use rigid-body physics.

The i5-1235U’s wins are concentrated in raw computational throughput. Its 93% lead in prime number finding and 27.4% lead in floating point math suggest it has a more robust FPU pipeline or better sustained clock behavior under heavy AVX-512-style loads. The integer math win (+5.5%) and random string sorting win (+1.9%) are modest but indicate the i5 handles certain data manipulation tasks slightly faster. The Cinebench R23 multi-core win (9774 vs 7912.5) is the most significant real-world advantage, as this test reflects long-duration rendering workloads where the i5’s higher 15W TDP allows it to maintain performance over time, compared to the i7’s 9W TDP.

For mixed workloads, the i7’s PassMark multithread score (14011 vs 12923, +8.4%) shows it manages concurrent threads better in short bursts. However, the i5’s higher average benchmark score (16770 vs 16320) suggests that in a broad set of applications, the i5 might edge ahead on aggregate throughput, even if it loses on responsiveness.

Architecture Differences

Both processors share the same Alder Lake architecture and 10 nm process node, but they diverge in core configuration and power envelope. The i7-1260U and i5-1235U both have 10 cores and 12 threads, but the i7 has a base clock of 1100 MHz and a boost clock of 4.70 GHz, while the i5 runs higher at 1300 MHz base but lower at 4.40 GHz boost. The i7’s higher boost clock is the primary driver of its single-core wins, while the i5’s higher base clock helps sustain multi-core loads.

The TDP difference is stark: the i7 is rated at 9W, the i5 at 15W. This 6W gap explains the Cinebench R23 multi-core reversal—the i5 can draw more power for longer, avoiding thermal throttling in long renders. The i7 compensates with a lower power draw, making it more suitable for fanless or ultra-thin designs, though the data shows this comes at a cost in sustained multi-threaded performance.

Cache is identical: 80 KB L1 per core, 1.25 MB L2 per core, and 12 MB shared L3. Memory support is also the same (DDR4 and DDR5, dual-channel). The PCIe interface differs slightly: the i7 lists PCIe Gen 4, while the i5 specifies PCIe Gen 4 with 20 lanes (CPU only). The integrated graphics differ, with the i7 featuring Iris Xe 96EU versus the i5’s Iris Xe 80EU, though no graphics benchmarks are provided in the data. Both use different sockets—Intel BGA 1781 for the i7 and Intel BGA 1744 for the i5—which means they are not pin-compatible replacements in the same motherboard.

The Verdict

Pick the Intel Core i7-1260U if your priority is snappy single-threaded performance, physics simulation, or short-duration multi-threaded tasks. The data shows it leads in Cinebench R15/R20 multi-core, Geekbench, and PassMark multithread, with a 52.5% advantage in physics and 20.3% in Geekbench single-core. Its 9W TDP also makes it the better option for thermally constrained laptops where battery life and low heat are critical.

Pick the Intel Core i5-1235U if you run long, sustained workloads like video rendering or scientific computation. The Cinebench R23 multi-core score (9774 vs 7912.5, +19%) is the strongest evidence of this, complemented by a 27.4% lead in floating point math and a 93% lead in prime number finding. Its higher 15W TDP allows it to maintain performance over time, making it the better choice for a laptop with active cooling that will sit on a desk for extended compute sessions.

For general consumers who do a mix of tasks, the i7-1260U’s 14 wins out of 19 tests, including all standard single-core benchmarks, make it the safer recommendation. The i5’s wins are in narrow, computationally intensive niches that most users will not encounter daily. The i7’s 0.1% lead in PassMark single-thread (3153 vs 3151) is negligible, but its 59.1% lead in Cinebench R15 single-core is not.

FAQ

Q: Which CPU has the higher boost clock?

A: The Intel Core i7-1260U has a boost clock of 4.70 GHz, while the Intel Core i5-1235U has a boost clock of 4.40 GHz.

Q: Why does the i5-1235U win Cinebench R23 multi-core but lose R15 and R20 multi-core?

A: The i5-1235U scores 9774 in R23 multi-core versus the i7’s 7912.5 (a 19% lead for the i5), but the i7 wins R15 multi-core (1203 vs 985) and R20 multi-core (4736 vs 4105). The R23 test is longer, and the i5’s higher 15W TDP (versus the i7’s 9W) likely allows it to sustain performance over the extended workload.

Q: Do both CPUs have the same amount of L3 cache?

A: Yes, both the i7-1260U and i5-1235U have 12 MB of shared L3 cache, along with identical L1 (80 KB per core) and L2 (1.25 MB per core) caches.

Q: Which processor is better for physics simulations?

A: The i7-1260U is significantly better, scoring 1046 in PassMark physics versus the i5-1235U’s 686, a 52.5% advantage.

Q: Are the two CPUs socket-compatible?

A: No, the i7-1260U uses Intel BGA 1781, while the i5-1235U uses Intel BGA 1744, so they cannot be swapped in the same motherboard.

Q: What is the difference in integrated graphics execution units?

A: The i7-1260U has Iris Xe 96EU, while the i5-1235U has Iris Xe 80EU, though no graphics benchmarks are provided in the data to quantify the performance difference.