Intel Core i3-10320 vs Intel Core i5-10400 Comparison

The Verdict

The recorded benchmark data splits these two Comet Lake desktop processors almost exactly down the middle: the Intel Core i3-10320 wins 9 of the 17 head-to-head tests, while the Intel Core i5-10400 wins 8. This is not a one-sided comparison; it is a study in contrasting priorities. The i3-10320 is the pick for single-threaded responsiveness and lightly threaded workloads, while the i5-10400 is the pick for heavy parallel throughput, particularly in data and math-heavy tasks. The i3-10320 leads in every Cinebench iteration, both single and multi-core, and also wins PassMark's single-thread test by a wide 11% margin. The i5-10400, however, dominates the PassMark suite, taking data compression, encryption, extended instructions, prime numbers, floating point math, integer math, multithreaded, and random string sorting. The overall database averages are close: the i3-10320 posts an average benchmark score of 14852 against the i5-10400's 14037, a difference of roughly 5.8% in favor of the i3. Yet the i5-10400's percentile rank (68th vs. 69th for the i3) is nearly identical, reflecting how different workloads reward each chip differently. For a user whose daily driver is office productivity, web browsing, or legacy single-threaded applications, the i3-10320 is the stronger choice. For a user who regularly compresses files, encrypts data, or runs multi-threaded compute, the i5-10400 is the better fit. There is no universal winner here; the correct pick depends entirely on the workload mix.

Where Each One Wins

The i3-10320 wins across the entire Cinebench family, which is notable because Cinebench is traditionally a multi-core-heavy render benchmark. In Cinebench R15 multi-core, the i3 scores 855 against the i5's 838, a 2% lead. In R20 multi-core, it is 3564 versus 3492, a 2.1% lead. In R23 multi-core, it is 8486 versus 8316, again a 2% lead. This is counterintuitive given that the i5 has two more physical cores and four more threads. The explanation lies in clock speeds: the i3-10320 has a base clock of 3.80 GHz and a boost of 4.60 GHz, whereas the i5-10400 runs at 2.90 GHz base and 4.30 GHz boost. The i3's higher frequencies compensate for its smaller core count in these specific render tests. The i3 also wins single-thread tests decisively, including PassMark single-thread (2841 vs. 2560, an 11% margin) and all three Cinebench single-core runs (R15: 120 vs. 118; R20: 503 vs. 493; R23: 1198 vs. 1174). Additionally, the i3 takes PassMark physics (689 vs. 669, a 3% lead).

The i5-10400 wins every other PassMark test, and by substantial margins. Its biggest victories are in data compression (187207 vs. 140255, a 25.1% lead), floating point math (26080 vs. 19483, 25.3%), integer math (41715 vs. 31071, 25.5%), and extended instructions (12501 vs. 9284, 25.7%). It also leads in random string sorting by 23.2% (23206 vs. 17821), data encryption by 15.2% (4078 vs. 3458), and multithreaded score by 16.9% (12006 vs. 9982). The i5's 12 threads (6 cores, 12 threads) give it a clear advantage in highly parallel, non-render workloads. The i5 also wins the prime numbers test, albeit narrowly at 34 vs. 32 (5.9%). The pattern is consistent: the i3 wins where clock speed matters most, and the i5 wins where core count and thread count matter most.

Architecture Differences

Both processors are built on Intel's Comet Lake architecture, use the 14 nm process node, and are fabricated by Intel. They share the same Intel Socket 1200, the same dual-channel DDR4 memory support, and the same 42.7 GB/s memory bandwidth. Both integrate UHD Graphics 630 and support PCIe Gen 3 with 16 lanes from the CPU. Neither supports ECC memory, and neither has an unlocked multiplier. The core configuration is the primary architectural difference: the i3-10320 has 4 cores and 8 threads, while the i5-10400 has 6 cores and 12 threads. That extra core and four extra threads are the i5's main structural advantage. Cache also differs: each core has 64 KB of L1 and 256 KB of L2 in both chips, but the shared L3 cache is 8 MB on the i3 and 12 MB on the i5, a 50% increase for the i5. Clock speeds differ markedly, as noted: the i3 runs at 3.80 GHz base and 4.60 GHz boost, while the i5 runs at 2.90 GHz base and 4.30 GHz boost. The i3's base clock is 31% higher, and its boost is 7% higher. Thermal design power also diverges: the i3 is rated at 91 W, while the i5 is rated at 65 W, a notable difference given the i5 has more cores. Both were released on the same date, April 29, 2020, and both remain Active in production status. The i3's part number is SRH3G, while the i5's is SRH3CSRH78. Neither has a launch MSRP recorded in the database.

FAQ

Q: Which processor has the higher clock speed?

A: The Intel Core i3-10320 has a base clock of 3.80 GHz and a boost clock of 4.60 GHz. The Intel Core i5-10400 has a base clock of 2.90 GHz and a boost clock of 4.30 GHz. The i3 is higher in both metrics.

Q: Does the i5-10400 have more cores and threads?

A: Yes. The i5-10400 has 6 cores and 12 threads, while the i3-10320 has 4 cores and 8 threads. The i5 also has a larger shared L3 cache at 12 MB compared to the i3's 8 MB.

Q: Which chip wins in single-threaded performance?

A: The i3-10320 wins every single-thread test in the database. It leads PassMark single-thread by 11% (2841 vs. 2560) and wins Cinebench R15 single-core (120 vs. 118), R20 single-core (503 vs. 493), and R23 single-core (1198 vs. 1174).

Q: Which chip wins in multi-threaded rendering?

A: The i3-10320 wins all three Cinebench multi-core tests, despite having fewer cores. In R15 multi-core, it scores 855 vs. 838. In R20 multi-core, it scores 3564 vs. 3492. In R23 multi-core, it scores 8486 vs. 8316. The margins are consistently around 2%.

Q: Where does the i5-10400 have its biggest advantages?

A: The i5-10400 wins the PassMark suite by large margins. Its biggest lead is 25.7% in extended instructions (12501 vs. 9284). It also leads by 25.5% in integer math, 25.3% in floating point math, 25.1% in data compression, and 23.2% in random string sorting.

Q: Are the two processors similar in overall standing?

A: Yes. The i3-10320 has a percentile rank of 69 against all CPUs, while the i5-10400 ranks at 68. Their average benchmark scores are 14852 and 14037, respectively. The i3's closest rival in the database is the Intel Core i7-9750H with a delta of -0.2%, while the i5's closest is the AMD EPYC 7552 with a delta of -0.6%.

Head-to-Head Benchmarks

The head-to-head data reveals a clean split: the i3-10320 owns Cinebench and single-thread tests, while the i5-10400 owns the PassMark compute suite. Starting with Cinebench, the i3 wins all six variants. In Cinebench R15 multi-core, the i3 scores 855 against 838, a 2% edge. In R15 single-core, it is 120 vs. 118, a 1.7% edge. Moving to R20, the i3 takes multi-core 3564 vs. 3492 (2.1%) and single-core 503 vs. 493 (2%). In R23, the i3 wins multi-core 8486 vs. 8316 (2%) and single-core 1198 vs. 1174 (2%). The consistency of these 2% margins across generations of the Cinebench test suggests a stable frequency advantage rather than a workload-specific fluke. The i3's 4.60 GHz boost clock versus the i5's 4.30 GHz boost clock is the most plausible driver of these wins.

The PassMark tests tell the opposite story. The i5-10400 wins 8 of the 11 PassMark tests, and its margins are far larger than the i3's Cinebench margins. The largest delta is in extended instructions, where the i5 scores 12501 versus the i3's 9284, a 25.7% lead. Integer math follows at 25.5% (41715 vs. 31071), and floating point math at 25.3% (26080 vs. 19483). Data compression shows a 25.1% lead (187207 vs. 140255), and random string sorting a 23.2% lead (23206 vs. 17821). Data encryption is less lopsided but still decisive at 15.2% (4078 vs. 3458). The multithreaded PassMark score favors the i5 by 16.9% (12006 vs. 9982), and the prime numbers test goes to the i5 by 5.9% (34 vs. 32).

The remaining PassMark tests go to the i3. The single-thread test is the i3's biggest win anywhere: 2841 vs. 2560, an 11% margin. The physics test goes to the i3 at 689 vs. 669, a 3% margin. Notably, the i3's single-thread score of 2841 is identical in both the "single_thread" and "singlethread" database entries, confirming consistency. Overall, the win count is 9 for the i3 and 8 for the i5, but the magnitude of the i5's wins is generally larger than the magnitude of the i3's wins. The i3's average win margin across its 9 victories is roughly 4.1% (counting the duplicate single-thread test once), while the i5's average win margin across its 8 victories is roughly 20.5%. This asymmetry is the key takeaway: the i3 wins narrowly and frequently, while the i5 wins broadly and decisively in the workloads it targets. Users who need raw parallel compute should not be swayed by the i3's higher win count, because the i5's wins are far more substantial in the tasks that matter for throughput. Conversely, users who prioritize single-thread speed will find the i3's 11% lead in PassMark single-thread and its clean sweep of Cinebench to be more relevant than the i5's multi-thread dominance.