Intel Core i3-8121U vs Intel Core i7-3632QM Comparison

The Verdict

The Intel Core i7-3632QM and Intel Core i3-8121U occupy the same overall performance tier, both landing at the 34th percentile of all CPUs with nearly identical average benchmark scores — 1219 for the i7 versus 1209 for the i3. The i7-3632QM wins six of eight head-to-head tests, dominating every Cinebench workload by roughly 11% across the board. The i3-8121U strikes back decisively in Geekbench, where its single-core score of 1149 crushes the i7's 613 by a massive 46.6% margin, and its multi-core score of 2215 edges out the i7's 2142 by 3.3%.

The practical verdict splits cleanly. If your workloads are render-centric or heavily threaded — Cinebench-style tasks that scale with cores and threads — the i7-3632QM is the clear choice, delivering a consistent ~10.9% advantage in every Cinebench test from R15 through R23. If your software leans on single-thread responsiveness or uses workloads similar to Geekbench's mixed integer and floating-point suite, the i3-8121U's modern architecture gives it a commanding lead that makes the older chip feel dated. The i3 also does all this at less than half the TDP: 15 watts versus 35 watts, which matters in thin-and-light laptops where thermals and battery life trump raw render performance.

Neither chip is a powerhouse by current standards — both sit at the same 34th percentile — but they fail in opposite directions. The i7 is a mobile workhorse from 2012 with four cores and eight threads, while the i3 is a 2018 dual-core with four threads that leans on architectural efficiency. Pick the i7 for sustained multi-threaded grunt, pick the i3 for single-core speed and efficiency.

Architecture Differences

The architectural gap here spans six years and a full process-node jump. The i7-3632QM is built on Intel's 22 nm Ivy Bridge process, packing 1,480 million transistors into a 160 mm² die. The i3-8121U uses Intel's 10 nm Cannon Lake process, with a much smaller 70.52 mm² die. That node shrink explains why the i3 can deliver competitive multi-core scores with only two physical cores while consuming 15 watts against the i7's 35 watts.

Core counts tell the structural story: the i7 has 4 cores and 8 threads, the i3 has 2 cores and 4 threads. Despite the i3 having half the cores, it nearly matches the i7 in multi-threaded Cinebench scores, which speaks to the generational efficiency gain of Cannon Lake over Ivy Bridge. The i7's larger 6 MB shared L3 cache versus the i3's 4 MB shared L3 partially compensates for its older architecture, but the i3's newer memory pipeline with DDR4 support and 38.4 GB/s memory bandwidth gives it a data-feeding advantage the i7 cannot match. The i7 lists dual-channel memory support without a bandwidth figure, while the i3 explicitly supports DDR4 at 38.4 GB/s.

A critical difference is integrated graphics: the i7 includes Intel HD 4000, while the i3 has no integrated graphics listed. That means the i3 requires a discrete GPU for any display output, whereas the i7 can drive a display on its own. The i3 compensates elsewhere, with PCIe Gen 3 across 16 lanes (CPU only), while the i7's PCIe configuration is unspecified. Both use dual-channel memory buses, both lack ECC support, and neither is multiplier-unlocked. The i7 uses the Intel Socket G2 (988B), the i3 uses Intel BGA 1440 — sockets that are not interchangeable.

Head-to-Head Benchmarks

The Cinebench results are strikingly uniform. Across all six Cinebench tests — R15, R20, and R23, each in single-core and multi-core variants — the i7-3632QM wins by almost exactly the same margin. In Cinebench R15 multi-core, the i7 scores 406 against the i3's 366, a 10.9% advantage. The single-core R15 test shows 57 versus 51, an 11.8% edge. R20 multi-core: 1693 versus 1527, again 10.9%. R20 single-core: 238 versus 215, a 10.7% lead. R23 multi-core: 4033 versus 3637, 10.9%. R23 single-core: 569 versus 513, 10.9%. The consistency is remarkable — the i7 is essentially 11% faster in every Cinebench scenario regardless of core count or test version. This pattern suggests a fundamental per-thread performance advantage in this workload, likely from the i7's higher thread count scaling well in render tasks.

Geekbench flips the script entirely. The i3-8121U wins single-core with a score of 1149 versus the i7's 613 — a 46.6% blowout that dwarfs any of the i7's Cinebench wins. The i3 also takes multi-core Geekbench at 2215 versus 2142, a 3.3% margin. This is a workload-dependent reversal: Geekbench's mixed integer, floating-point, and memory tests clearly favor the i3's modern architecture, while Cinebench's render loop favors the i7's extra cores and larger cache. The i3's single-core score is nearly double the i7's, meaning that for any single-threaded task with Geekbench-like characteristics, the i3 is in a different performance class.

FAQ

Q: Which CPU wins more benchmarks overall?

A: The Intel Core i7-3632QM wins 6 of 8 head-to-head tests, taking every Cinebench R15, R20, and R23 workload. The Intel Core i3-8121U wins 2 tests, both in Geekbench.

Q: How much faster is the i7 in Cinebench multi-core?

A: The i7-3632QM leads by 10.9% in Cinebench R15 multi-core (406 vs 366), Cinebench R20 multi-core (1693 vs 1527), and Cinebench R23 multi-core (4033 vs 3637).

Q: Why does the i3 win Geekbench single-core by such a large margin?

A: The i3-8121U scores 1149 in Geekbench single-core versus the i7-3632QM's 613, a 46.6% advantage. This likely stems from the i3's newer 10 nm Cannon Lake architecture and DDR4 memory support, which improve per-clock efficiency in mixed workloads.

Q: Do both CPUs have the same average benchmark score?

A: Almost. The i7-3632QM averages 1219 across all benchmarks, while the i3-8121U averages 1209. Both sit at the 34th percentile of all CPUs.

Q: Which CPU consumes less power?

A: The i3-8121U has a 15 watt TDP, while the i7-3632QM has a 35 watt TDP. The i3 uses less than half the power budget.

Q: Does either CPU have integrated graphics?

A: The i7-3632QM includes Intel HD 4000 integrated graphics. The i3-8121U has no integrated graphics listed, so it requires a discrete GPU for display output.

Where Each One Wins

The i7-3632QM wins in every Cinebench workload, making it the choice for render farms, video encoding pipelines, or any batch processing that uses Cinebench-like algorithms. Its 4 cores and 8 threads, combined with 6 MB of L3 cache, give it a consistent ~11% edge across all render tests. The data shows this is not a marginal or test-specific win — the i7 is uniformly faster in every Cinebench variant, from single-core R15 to multi-core R23. If your software is built around Cinebench's rendering engine, the i7 is the safer bet despite its age.

The i3-8121U wins in Geekbench, particularly single-core where its 1149 score nearly doubles the i7's 613. This makes it the pick for general desktop responsiveness, office productivity, web browsing, and any application where single-threaded burst performance dominates. The i3's 2215 Geekbench multi-core score also tops the i7's 2142, meaning even in multi-threaded Geekbench loads, the newer architecture holds a slight edge. The i3's 15 watt TDP versus the i7's 35 watts also makes it the obvious choice for battery-powered ultraportables, provided the system has a discrete GPU for display.

Specification Differences

The two CPUs differ on nearly every core specification. The i7-3632QM has 4 cores and 8 threads, while the i3-8121U has 2 cores and 4 threads. Both run at identical base clocks of 2.20 GHz and boost clocks of 3.20 GHz. The i7's TDP is 35 watts, the i3's is 15 watts. The i7 uses Intel Socket G2 (988B), the i3 uses Intel BGA 1440.

Architecture separates them: the i7 is Ivy Bridge on a 22 nm process with 1,480 million transistors and a 160 mm² die; the i3 is Cannon Lake on a 10 nm process with a 70.52 mm² die and no listed transistor count. The i7's codename is Ivy Bridge, the i3's is Cannon Lake. Their generations are listed as Core i7 (Ivy Bridge) and Core i3 (Kaby Lake-U Refresh) respectively.

Cache configurations differ in L3 only: the i7 has 6 MB shared L3, the i3 has 4 MB shared L3. Both have 64 KB L1 and 256 KB L2 per core. Memory support differs: the i3 explicitly supports DDR4 with 38.4 GB/s bandwidth, while the i7 lists dual-channel support with no specific memory type or bandwidth figure. The i3 has PCIe Gen 3 with 16 lanes (CPU only); the i7's PCIe configuration is not specified.

Graphics and availability differ: the i7 includes Intel HD 4000 integrated graphics, the i3 has none. The i3 is marked as end-of-life production status, while the i7's production status is not listed. The i3's part number is SRCVC. The i7 was released in 2012, the i3 in 2018. Neither has a launch MSRP listed. Both lack ECC support and neither has an unlocked multiplier.