CPU Comparison

The Intel Core i5-9400T and Intel Atom C5125 occupy different corners of the Intel lineup, but the benchmark data places them in a surprisingly close overall performance class. The Core i5-9400T is a 6-core, 6-thread Coffee Lake desktop part with a 35 W TDP, while the Atom C5125 is an 8-core, 8-thread Parker Ridge server/workstation chip with a 50 W TDP. Across six Cinebench tests, the Atom wins every single one, yet the margins are consistently narrow, and the aggregate scores differ by less than 1%. This creates a fascinating comparison where the "server" Atom outperforms the "desktop" Core i5 in raw compute, but the architectural and platform trade-offs tell a more nuanced story.

Head-to-Head Benchmarks

The Intel Atom C5125 claims a clean sweep in the head-to-head Cinebench results, but the victories are modest in percentage terms. In Cinebench R15 multicore, the Atom scores 739 against the Core i5-9400T's 695, a 6% advantage. The single-core R15 result shows a similar pattern: 104 for the Atom versus 97 for the Core i5, a 6.7% lead. Moving to Cinebench R20, the Atom posts 3081 in multicore versus 2896, again a 6% gap; single-core is 434 versus 408, another 6% difference. The R23 results mirror this exactly: 7336 versus 6896 in multicore and 1035 versus 973 in single-core, both at a 6% delta.

The consistency of the 6% margin across nearly every test is notable. It suggests the Atom's advantage is systematic rather than workload-specific. The largest relative win comes in Cinebench R15 single-core, where the 6.7% delta stands out slightly from the rest. The Core i5-9400T does not win a single benchmark in this pair, recording 0 wins against the Atom's 6. The scores are close enough that the data implies these processors are in the same performance tier, but the Atom's higher base clock of 2.80 GHz versus 1.80 GHz for the Core i5 likely contributes to its consistent edge, even without a boost clock listed for the Atom. The Core i5 does have a 3.40 GHz boost clock, but the Atom's sustained 2.80 GHz appears to be the deciding factor in these multi-threaded and single-threaded renders.

Where Each One Wins

The Intel Atom C5125 wins every benchmark in this comparison, so the use-case split is not about which processor is faster, but about what the benchmark scores mean in context. The Atom's wins in Cinebench R15, R20, and R23, both multicore and single-core, indicate that it is the better choice for sustained CPU rendering workloads. Its 8 cores and 8 threads, combined with a 2.80 GHz base clock, deliver higher throughput in threaded tasks; the data shows a 6% lead in R23 multicore, translating to 6896 points versus 7336. For single-threaded responsiveness, the Atom also leads, with a 6% advantage in R23 single-core (1035 versus 973).

The Core i5-9400T, despite losing every benchmark, still has a role based on its platform characteristics rather than its scores. With a 35 W TDP, it draws less power than the Atom's 50 W TDP, making it suitable for systems where thermal and power budgets are tight. It also features integrated UHD 630 graphics, which the Atom lacks entirely (integrated graphics listed as N/A). This means the Core i5 can handle display output without a discrete GPU, while the Atom requires a separate graphics solution. The Core i5's desktop socket (Intel Socket 1151) is also a different ecosystem from the Atom's BGA 2106, which is soldered and more common in embedded or server boards. So while the Atom wins on raw compute, the Core i5 wins on power efficiency and integrated graphics capability, as inferred from the specification data.

FAQ

Q: Which processor has a higher single-core score in Cinebench R23?

A: The Intel Atom C5125 scores 1035 in Cinebench R23 single-core, while the Intel Core i5-9400T scores 973, giving the Atom a 6% lead.

Q: How do the two processors compare in multi-core performance?

A: The Atom C5125 wins all multi-core tests, with a 6% advantage in Cinebench R15 (739 versus 695), R20 (3081 versus 2896), and R23 (7336 versus 6896).

Q: Does the Intel Core i5-9400T have integrated graphics?

A: Yes, the Core i5-9400T includes Intel UHD 630 integrated graphics, whereas the Atom C5125 has no integrated graphics (listed as N/A).

Q: What is the TDP difference between the two processors?

A: The Intel Core i5-9400T has a TDP of 35 W, while the Intel Atom C5125 has a TDP of 50 W, making the Core i5 the lower-power part.

Q: Which processor supports ECC memory?

A: The Intel Atom C5125 supports ECC memory, while the Intel Core i5-9400T does not.

Q: What is the release date of each processor?

A: The Intel Core i5-9400T was released on 2018-08-31, and the Intel Atom C5125 was released on 2022-06-05.

Specification Differences

The two processors differ in several core specifications. The Core i5-9400T has 6 cores and 6 threads, while the Atom C5125 has 8 cores and 8 threads. The base clock is 1.80 GHz for the Core i5 and 2.80 GHz for the Atom; the Core i5 also lists a boost clock of 3.40 GHz, while the Atom has no boost clock listed. TDP differs significantly: 35 W for the Core i5 versus 50 W for the Atom. The socket is also different, with the Core i5 using Intel Socket 1151 and the Atom using Intel BGA 2106. Memory bandwidth is close but not identical, at 42.7 GB/s for the Core i5 and 46.9 GB/s for the Atom. ECC memory support is absent on the Core i5 but present on the Atom. The Core i5 includes UHD 630 integrated graphics; the Atom has N/A for integrated graphics. The Core i5 is marked as end-of-life, while the Atom is active. The process node is 14 nm for the Core i5 and 10 nm for the Atom. Release dates are 2018-08-31 for the Core i5 and 2022-06-05 for the Atom.

Architecture Differences

The architectural split between these two parts is fundamental. The Core i5-9400T is built on Coffee Lake architecture with the Coffee Lake codename, part of the Core i5 (Coffee Lake Refresh) generation, using a 14 nm process node from Intel. Its cache hierarchy includes 64 KB of L1 per core, 256 KB of L2 per core, and 9 MB of shared L3 cache. The Atom C5125, in contrast, is based on Parker Ridge codename, part of the Atom (Tremont) generation, using a 10 nm process node. Its cache structure is notably different: 64 KB of L1 per core, but a much larger 4.5 MB of L2 per module, with no L3 cache listed. The L2 cache design reflects the Atom's modular architecture, where cores are grouped and share L2 within a module. The Core i5's larger shared L3 cache (9 MB) is absent on the Atom, which relies on its generous per-module L2 instead. Both support DDR4 memory with dual-channel buses, but the Atom's memory bandwidth is slightly higher at 46.9 GB/s versus 42.7 GB/s. The Atom also supports ECC memory, a feature not available on the Core i5, which aligns with its server/workstation market segment. The Core i5 targets the desktop segment, while the Atom is aimed at server/workstation use, and this is reflected in the feature set.

The Verdict

The data points to a clear, if narrow, performance winner: the Intel Atom C5125. It outperforms the Core i5-9400T in every Cinebench test, with a consistent 6% margin in most cases and a 6.7% edge in R15 single-core. The Atom's 8 cores and 2.80 GHz base clock give it a sustained advantage that the Core i5's 3.40 GHz boost cannot overcome in these workloads. The Atom also brings ECC memory support and a newer 10 nm process node, which are meaningful for reliability and efficiency in server contexts. Its launch MSRP is $335, and it is an active product.

The Core i5-9400T, however, is not without its merits. Its 35 W TDP is lower than the Atom's 50 W, making it a better fit for passively cooled or power-constrained desktop builds. The integrated UHD 630 graphics mean it can serve as a complete desktop solution without a discrete GPU, something the Atom cannot do. It also uses a socketed platform (LGA 1151), which offers upgrade flexibility compared to the Atom's soldered BGA 2106. For users who need a low-power desktop CPU with graphics, the Core i5 is the pragmatic choice. For users who need raw multi-threaded compute in a server or workstation role, with ECC support, the Atom C5125 is the better option based on the benchmark results. The aggregate scores reinforce this: the Atom's average benchmark score of 2122 sits just below the Core i5's 2136, but the head-to-head wins are what matter. If the workload is Cinebench-style rendering, the Atom wins. If the workload is general desktop use with integrated graphics and low power draw, the Core i5 is the sensible pick. The verdict is not about which is "better" overall, but which fits the platform and use-case, and the data clearly favors the Atom for raw compute.