Intel Core i3-7300T vs Intel Core i3-8121U Comparison

The Intel Core i3-7300T and Intel Core i3-8121U are both dual-core, four-thread processors, but they represent two very different design philosophies from Intel. The 7300T is a 35-watt desktop part built on the mature 14 nm Kaby Lake node, while the 8121U is a 15-watt mobile chip from the short-lived 10 nm Cannon Lake generation. Despite their architectural and platform differences, the benchmark data reveals a surprisingly close contest, with the mobile part holding a consistent, if narrow, edge across every measured workload.

Head-to-Head Benchmarks

The data is unambiguous: the Intel Core i3-8121U wins all five head-to-head comparisons, though by a remarkably slim margin. In Cinebench R15 multi-core, the 8121U scores 366 against the 7300T’s 354, a 3.3% advantage. That same 3.3% delta appears in Cinebench R20 multi-core, where the 8121U posts 1527 versus 1477. The pattern holds in single-core tests as well; in Cinebench R20 single-core, the 8121U manages 215 points, edging out the 7300T’s 208. The newest Cinebench R23 test tells the same story: multi-core results show 3637 for the 8121U and 3519 for the 7300T, while single-core results show 513 and 496, respectively.

Every deltaPct in the head-to-head table is exactly -3.3% (or -3.2% for R23 multi-core), which indicates the 8121U’s lead is remarkably consistent across both single-threaded and multi-threaded workloads. This uniformity is striking because the two chips have very different clock profiles — the 7300T runs at a fixed 3.50 GHz with no boost, while the 8121U has a 2.20 GHz base clock that boosts to 3.20 GHz. The fact that the lower-clocked mobile chip wins every test suggests the architectural efficiency of Cannon Lake’s 10 nm process more than compensates for the raw clock deficit.

Looking at the aggregate picture, the average benchmark score for the 8121U is 1209, while the 7300T sits at 1211. This puts the 7300T a hair ahead in the overall average, but that figure includes Geekbench results that only exist for the 8121U. In the directly comparable Cinebench suite, the 8121U leads every single test. The two chips also occupy the same 34th percentile among all CPUs, meaning they land in essentially the same performance tier, despite the mobile part’s lower TDP.

Architecture Differences

The most fundamental difference lies in the manufacturing process and microarchitecture. The Core i3-7300T is built on Intel’s 14 nm process using the Kaby Lake architecture, a refined version of the Skylake design. The Core i3-8121U, by contrast, uses the 10 nm Cannon Lake architecture, which was Intel’s first attempt at 10 nm production. The die size for the 8121U is listed at 70.52 mm², while no die size is provided for the 7300T, making direct comparison difficult. The 8121U’s production status is “End-of-life,” reflecting Cannon Lake’s short and troubled lifespan, whereas the 7300T remains “Active.”

Both chips share identical cache hierarchies: 64 KB of L1 per core, 256 KB of L2 per core, and 4 MB of shared L3. They also share the same dual-channel DDR4 memory support with 38.4 GB/s of bandwidth. However, the integrated graphics situation diverges sharply. The 7300T includes an Intel HD 630 iGPU, while the 8121U lists no integrated graphics at all — a notable omission for a mobile processor that might otherwise be expected to handle display output without a discrete GPU.

The sockets are completely different, reflecting their intended markets: the 7300T uses Intel Socket 1151 for desktop motherboards, while the 8121U uses Intel BGA 1440, meaning it is soldered directly to the board and not upgradeable. The TDP gap is substantial — 35 watts for the desktop part versus 15 watts for the mobile part — which makes the 8121U’s benchmark wins all the more impressive from an efficiency standpoint. The 7300T also has no boost clock, running at a fixed 3.50 GHz, while the 8121U can ramp from 2.20 GHz up to 3.20 GHz. Neither chip has an unlocked multiplier, and both use PCIe Gen 3 with 16 CPU lanes.

Where Each One Wins

The Core i3-8121U wins every benchmark where both chips were tested, making its case straightforward: it is the faster processor in pure computational terms. The Cinebench R23 multi-core score of 3637 versus 3519 shows a 3.2% lead, and the single-core score of 513 versus 496 shows a 3.3% lead. This means the 8121U is the better choice for any workload that relies on CPU throughput, whether that is rendering, encoding, or general productivity. Its wins are consistent across both single-threaded and multi-threaded tests, so there is no scenario in the data where the 7300T pulls ahead.

However, the 7300T has its own advantages that do not show up in the Cinebench scores. It includes an integrated GPU, the Intel HD 630, making it a self-contained solution for a desktop build without a discrete graphics card. The 8121U has no iGPU, so it requires a separate GPU for any display output. The 7300T is also a socketed desktop processor, meaning it can be installed, removed, and upgraded in a standard Socket 1151 motherboard. The 8121U is BGA-only, permanently attached to the board. For a user building a low-power desktop system, the 7300T’s 35-watt TDP is still modest, and its active production status means it remains available.

The 8121U’s domain is clearly mobile and embedded systems where the 15-watt TDP is a critical advantage. Its 10 nm process and smaller die size (70.52 mm²) suggest better power efficiency per unit of work, even though the exact power draw is not directly measured in the benchmark data. It is also the only one of the two with a boost clock, allowing it to reach 3.20 GHz when thermal headroom permits. The 8121U’s Geekbench results — 2215 multi-core and 1149 single-core — are not available for the 7300T, so they cannot be directly compared, but they do show the 8121U is a capable performer in a low-power envelope.

FAQ

Q: Which processor is faster in multi-core workloads?

A: The Intel Core i3-8121U wins every multi-core benchmark in the comparison. It scores 366 in Cinebench R15, 1527 in R20, and 3637 in R23, compared to 354, 1477, and 3519 for the Core i3-7300T, respectively.

Q: Does the Core i3-8121U have integrated graphics?

A: No. The 8121U lists no integrated graphics at all, while the Core i3-7300T includes an Intel HD 630. This means the 8121U requires a discrete GPU for display output.

Q: What is the TDP difference between these two chips?

A: The Core i3-7300T has a TDP of 35 watts, while the Core i3-8121U has a TDP of 15 watts. The 8121U still manages to outperform the 7300T in every shared benchmark despite the lower power envelope.

Q: Are these processors the same generation?

A: No. The 7300T is based on Kaby Lake (14 nm process), released in January 2017, while the 8121U is based on Cannon Lake (10 nm process), released in May 2018. The 8121U is listed as end-of-life, while the 7300T remains active.

Q: Do both processors support the same memory?

A: Yes. Both support dual-channel DDR4 memory with a bandwidth of 38.4 GB/s, and both use PCIe Gen 3 with 16 CPU lanes. Neither supports ECC memory.

Q: Which processor has a higher clock speed?

A: The Core i3-7300T runs at a fixed 3.50 GHz with no boost clock. The Core i3-8121U has a 2.20 GHz base clock but can boost up to 3.20 GHz. Despite the 7300T’s higher base clock, the 8121U wins all benchmark comparisons.

Specification Differences

| Specification | Intel Core i3-7300T | Intel Core i3-8121U |

|---|---|---|

| Base Clock | 3.50 GHz | 2.20 GHz |

| Boost Clock | None | 3.20 GHz |

| TDP | 35 W | 15 W |

| Socket | Intel Socket 1151 | Intel BGA 1440 |

| Architecture | Kaby Lake | Cannon Lake |

| Process Node | 14 nm | 10 nm |

| Die Size | Not specified | 70.52 mm² |

| Integrated Graphics | Intel HD 630 | None |

| Market Segment | Desktop | Mobile |

| Production Status | Active | End-of-life |

| Release Date | 2017-01-02 | 2018-05-04 |

| Part Number | SR35M | SRCVC |

The two processors share identical core counts (2 cores, 4 threads), L1/L2/L3 cache sizes (64 KB per core, 256 KB per core, 4 MB shared), memory support (DDR4, dual-channel, 38.4 GB/s), PCIe configuration (Gen 3, 16 lanes), and ECC support (none). Neither has an unlocked multiplier. The generation field lists both under “Core i3,” though the 8121U notes “Kaby Lake-U Refresh” as its generation label.