Intel Core i7-1355U vs Intel Core i7-8700 Comparison

# Head-to-Head Benchmarks

The database pits the Intel Core i7-1355U against the Intel Core i7-8700 across 17 discrete workload tests, and the results show a decisive, though domain-dependent, split. The newer Raptor Lake part takes 13 of the 17 tests, often by a wide margin. The Coffee Lake chip, however, retains a clear lead in peak multi-core throughput and memory-bound workloads, where its higher core count and higher power envelope come into play.

The single largest win for the i7-1355U is in the Cinebench R15 multi-core test, where it scores 1393 against 1091 for the i7-8700: a 27.7% advantage. The Cinebench R20 multi-core result follows a similar pattern: 4949 for the i7-1355U versus 4548 for the i7-8700, an 8.8% lead. In single-threaded Cinebench R23, the 1355U extends its edge to 19.4% (1825 versus 1528). Its largest margin, 119.1%, comes in the PassMark data encryption test, where it scores 9831 to 4488. The i7-8700 only wins the PassMark random string sorting test (23963 vs 17631, a 26.4% lead) and the multi-threaded Cinebench tests: the R20 multicore test (4548 versus 4949, a 8.8% lead for the i7-8700) and the R23 multicore test (10829 versus 8286, a 23.5% lead for the i7-8700).

On the other side, the i7-8700 counters in the single-threaded PassMark tests where the i7-1355U leads by large margins: 31% in single thread (3444 versus 2629) and 31% in the identical single-thread test. The i7-8700 also wins the PassMark integer math test by 15.9% (52002 versus 44881) and the floating point math test by 25.6% (34965 versus 27839). The i7-1355U counters in the PassMark physics test (888 versus 732, a 21.3% lead) and the extended instruction test (8726 versus 12432, a 29.8% lead for the i7-8700).

Architecture Differences

The two CPUs diverge in nearly every fundamental architectural aspect. The i7-1355U is built on Intel's Raptor Lake-U architecture, a 10 nm class process node, and features 10 cores with 12 threads. The core configuration is split: 2 performance cores and 8 efficient cores, a hybrid layout designed for mobile power efficiency. The i7-8700 uses the older Coffee Lake architecture on a 14 nm process, with 6 cores and 12 threads, a homogeneous design.

The i7-1355U includes an L1 cache of 80 KB per core and an L2 cache of 1.25 MB per core, shared L3 cache of 12 MB. The i7-8700 has 64 KB of L1 cache per core, 256 KB of L2 per core and also a 12 MB shared L3. The i7-1355U integrates Iris Xe Graphics with 96 execution units; the i7-8700 ships with the UHD Graphics 630.

Memory support also differs: the i7-1355U supports both DDR4 and DDR5 across a dual-channel interface, while the i7-8700 is limited to DDR4. The i7-1355U uses the Intel BGA 1744 socket, while the i7-8700 uses the LGA 1151 socket. Both are mobile and desktop segments respectively, which aligns with their design targets. The i7-1355U is a mobile part with a 15 W TDP; the i7-8700 is a desktop processor with a 65 W TDP.

The Verdict

The data shows two very different processors aimed at different workloads. The Core i7-1355U is the clear winner in short-burst, lightly threaded and latency-sensitive workloads. Its 12 threads and high boost clocks, plus newer microarchitecture, deliver 9% to 31% faster results in the Cinebench single-core tests and most PassMark single-thread tests. It also dominates in the PassMark integer math (15.9% faster), floating point math (25.6% faster) and physics (21.3% faster) tests.

The i7-8700 is the better choice for all-core sustained workloads. Its six full-size cores and 65 W power class allow it to beat the i7-1355U in multi-core Cinebench R23: 10829 versus 8286, a 23.5% lead. It also wins the multi-thread PassMark test (14299 versus 12756, a 12.1% lead), data compression (187009 versus 155727, a 16.7% lead), extended instructions (12432 versus 8726, a 29.8% lead), and random string sorting (23963 versus 17631, a 26.4% lead).

Strictly from the benchmark data: pick the i7-1355U for single-thread, mobile-centric and latency-sensitive workloads. Pick the i7-8700 when the application shares the load across all cores, and its higher sustained power can be used.

FAQ

Q: How does the Core i7-1355U compare to the Core i7-8700 in single-threaded performance?

A: The i7-1355U leads in all single-core tests. The biggest gap is in Cinebench R23 single-core: 1825 versus 1528 for the i7-8700, a 19.4% advantage. They also lead 31% in PassMark single thread (3444 vs 2629).

Q: Where does the i7-8700 win?

A: The i7-8700 wins all multi-core tests. The largest is Cinebench R23 multi-core, 10830 vs 8286 for the i7-1355U, a 23.5% advantage. It also leads in PassMark multi-threaded tests (14299 vs 12756, or 12.1%) and data compression (187009 vs 155727, or 16.7%).

Q: Is the i7-1355U more efficient than the i7-8700?

A: In the measured tests, yes. The 1355U wins in Cinebench R20 single-core (698 vs 641 of the 8700, an 8.9% lead), and all PassMark single-thread tests. It also has a 119.2% lead in the PassMark data encryption test (9831 vs 4488). The 8700 only wins in multi-core tests and PassMark string sorting (23963 vs 17631) test, where it is 26.4% faster.

Q: What is the biggest benchmark win for the Core i7-1355U?

A: The biggest win is the PassMark data encryption test: 9831 vs 4488 for the Core i7-8700, a 119.2% lead. It also has a 67% lead in Cinebench R15 single-core (255.5 vs 153) and a 45.7% lead in PassMark prime number test (51 vs 35).

Q: What is the biggest win for Core i7-8700?

A: The Core i7-8700's biggest wins are the multi-core tests. It leads by 23.5% in Cinebench R23 multi-core (10830 vs 8286). It also leads by 26.4% in random string sorting (23963 vs 17631) and by 29.8% in extended instructions (12432 vs 8726).

Q: Are these CPUs comparable for gaming?

A: The data does not include gaming, but the results are clear. The i7-1355U is 31% faster in single-threaded tests. The i7-8700 is 12.1% faster in multi-threaded tests. For gaming, the i7-1355U would be the choice for framerate-sensitive titles, while the i7-8700 would be the choice for heavily multithreaded titles.

Where Each One Wins

Choose the Intel Core i7-1355U if your workload is short, latency-sensitive, or mobile. The i7-1355U wins all single-threaded tests and latency-sensitive tests. It wins in Cinebench R23 single (1825 vs 1528), PassMark single threaded (3444 vs 2629), data compression (155727 vs 187009, a 16.7% lead), and the integer math test (52002 vs 44881, a 15.9% lead). It also wins the floating point math test (34965 vs 27839, a 25.6% lead) and the physics test (888 vs 732, a 21.3% lead).

Choose the Intel Core i7-8700 for sustained multi-core workloads: the 8700 dominates in all multi-core tests. It wins the Cinebench R23 multi-core test (10830 vs 8286, a 23.5% lead), the Cinebench R20 multi-core (4949 vs 4549, an 8.8% lead), the PassMark multi-thread test (14299 vs 12756, a 12.1% lead). It also wins in the compression (187009 vs 155727, a 16.7% lead), the extended instruction test (12432 vs 8726, a 29.8% lead), and the random string sort (23963 vs 17631, a 26.4% lead). The 8700's higher base power and six full-size cores make the difference in sustained throughput.