Intel Atom x7405C vs Intel Pentium Gold G6405 Comparison

The Intel Pentium Gold G6405 and Intel Atom x7405C are both active Intel processors, but they occupy very different corners of the market. The Pentium is a desktop part built on the 14 nm Comet Lake architecture, while the Atom is a 10 nm mobile chip using the newer Gracemont efficiency cores. Despite their contrasting designs, the benchmark data shows they land in a similar performance tier, with the Atom winning the majority of head-to-head tests while the Pentium holds a distinct advantage in specific workloads.

Head-to-Head Benchmarks

The most striking result is the Atom’s near-sweep of the benchmark suite, winning 13 of 16 comparisons. Its largest victory comes in PassMark’s data encryption test, where it scores 4004 against the Pentium’s 1385 — a massive 65.4% advantage. This is not a marginal win; it indicates the Atom’s architecture handles cryptographic instructions far more efficiently. Similarly, in extended instructions, the Atom posts 2771 versus 1711, a 38.3% lead that points to better support for modern SIMD and vector workloads.

Multi-threaded rendering also favors the Atom decisively. In Cinebench R23 multi-core, the Atom scores 4435 compared to the Pentium’s 3266, a 26.4% difference. The same pattern appears in Cinebench R20 multi-core (1862 vs 1371, 26.4% lead) and Cinebench R15 multi-core (446 vs 329, 26.2% lead). The Atom’s four physical cores, even at a much lower 1.70 GHz base clock, consistently outpace the Pentium’s two cores with Hyper-Threading, which runs at 4.10 GHz. This suggests the Atom’s per-core efficiency at higher boost clocks (up to 3.40 GHz) more than compensates for its lower sustained frequency.

The Atom also wins in PassMark’s multithread test, scoring 5218 against 3790, a 27.4% margin. Physics simulation shows a 32% advantage (460 vs 313), and prime number finding shows a 31.8% lead (22 vs 15). Even in floating point math, where desktop chips traditionally excel, the Atom edges ahead at 9063 versus 8390, a 7.4% win. Integer math follows suit at 14669 vs 13265, a 9.6% margin. Random string sorting is closer, with the Atom winning 8089 to 7456, a 7.8% difference.

The Pentium Gold G6405 does have one clear area of dominance: single-threaded performance. In PassMark’s single-thread test, it scores 2253 against the Atom’s 1675, a 34.5% advantage. This is the only test where the Pentium wins by a large margin, aside from data compression, where it narrowly beats the Atom 59224 to 56317, a 5.2% lead. Interestingly, the single-core Cinebench results tell a different story: the Atom wins R20 single-core 262 to 193 (26.3% lead) and R23 single-core 626 to 461 (26.4% lead). This discrepancy between PassMark and Cinebench single-thread tests suggests the Atom’s Gracemont cores are highly optimized for certain instruction sequences, while the Pentium’s older Comet Lake cores have strengths in other areas.

Where Each One Wins

The Intel Atom x7405C is the clear winner for multi-threaded and throughput-oriented tasks. Its 4-core, 4-thread configuration, combined with a 3.40 GHz boost clock, delivers superior results in rendering, encryption, and math-heavy workloads. The data shows it leads by 26-27% across Cinebench multi-core tests and by 27.4% in PassMark multithread. For users running parallel workloads like video encoding, data processing, or scientific simulations, the Atom is the more capable part despite its mobile pedigree. Its wins in data encryption (65.4% ahead) and extended instructions (38.3% ahead) also make it the better choice for security-sensitive applications or code that leverages modern instruction sets.

The Pentium Gold G6405 wins in scenarios where single-thread responsiveness and legacy software compatibility matter most. Its 34.5% lead in PassMark single-thread performance indicates faster execution of lightly-threaded applications, such as older games or productivity software that doesn’t scale across cores. The 5.2% win in data compression also suggests it handles certain memory-bound, latency-sensitive tasks more effectively. However, its wins are fewer and narrower. With only 3 benchmark victories out of 16, the Pentium is the specialist, while the Atom is the generalist. The Pentium’s 4.10 GHz base clock (with no boost) gives it a fixed high-frequency advantage, but this only translates to wins in specific workloads where the Atom’s lower clock speed (1.70 GHz base) becomes a bottleneck.

FAQ

Q: Which CPU has better multi-core performance?

A: The Intel Atom x7405C wins decisively in all multi-core tests. It scores 4435 in Cinebench R23 multi-core versus 3266 for the Pentium Gold G6405, a 26.4% advantage. PassMark multithread also favors the Atom at 5218 vs 3790, a 27.4% lead.

Q: Is the Pentium Gold G6405 faster in single-threaded tasks?

A: It depends on the benchmark. The Pentium wins PassMark single-thread by a 34.5% margin (2253 vs 1675). However, the Atom wins both Cinebench R20 single-core (262 vs 193, 26.3% lead) and R23 single-core (626 vs 461, 26.4% lead).

Q: How do the two chips compare in data encryption?

A: The Atom is far superior, scoring 4004 in PassMark data encryption versus 1385 for the Pentium, a 65.4% gap. This is the largest performance difference in the entire benchmark suite.

Q: Which processor has the higher clock speed?

A: The Pentium Gold G6405 has a fixed base clock of 4.10 GHz with no boost clock. The Atom x7405C has a base clock of 1.70 GHz but boosts up to 3.40 GHz, so peak frequency is still lower than the Pentium’s sustained rate.

Q: What are the core and thread counts?

A: The Pentium Gold G6405 has 2 cores and 4 threads. The Intel Atom x7405C has 4 cores and 4 threads. The Atom lacks Hyper-Threading, while the Pentium supports it.

Q: Which CPU has better memory bandwidth?

A: The Pentium Gold G6405 offers 42.7 GB/s of memory bandwidth via dual-channel DDR4. The Atom x7405C provides 38.4 GB/s through single-channel memory, though it supports both DDR4 and DDR5.

Specification Differences

The two processors differ across nearly every major specification. The Pentium Gold G6405 uses 2 cores and 4 threads, while the Atom x7405C has 4 cores and 4 threads. Clock speeds diverge sharply: the Pentium runs at a fixed 4.10 GHz with no boost, whereas the Atom has a 1.70 GHz base clock and a 3.40 GHz boost. Thermal design power is another major split, with the Pentium rated at 58W TDP versus the Atom’s 12W TDP.

Memory support also differs. The Pentium supports DDR4 only, while the Atom supports both DDR4 and DDR5. Memory bus width is dual-channel on the Pentium and single-channel on the Atom, resulting in a small bandwidth advantage for the Pentium (42.7 GB/s vs 38.4 GB/s). The PCIe configuration is also different: the Pentium offers 16 Gen 3 lanes (CPU only), while the Atom offers only 9 Gen 3 lanes.

Integrated graphics are present on the Pentium as UHD Graphics 610, whereas the Atom has no integrated graphics (N/A). The socket types are incompatible: the Pentium uses Intel Socket 1200, while the Atom uses Intel BGA 1264. The Pentium has a launch MSRP of $64, while the Atom’s launch MSRP is $57. Release dates differ as well, with the Pentium launching in March 2021 and the Atom in April 2024.

Architecture Differences

The architectural divide between these chips is fundamental. The Pentium Gold G6405 is built on Intel’s 14 nm process node under the Comet Lake architecture (codename Comet Lake-R). The Atom x7405C uses a 10 nm process node with the Amston Lake architecture (codename Amston Lake), which is based on Gracemont efficiency cores. This generational leap is reflected in the cache hierarchy: the Pentium has 64 KB of L1 cache per core and 256 KB of L2 per core, with 4 MB of shared L3. The Atom has 96 KB of L1 per core, 2 MB of shared L2, and 6 MB of shared L3.

The Pentium’s cache layout is per-core, while the Atom uses shared L2 and L3 pools, which helps its four cores coordinate more efficiently. The Atom’s Gracemont cores are designed for power efficiency, which explains its 12W TDP versus the Pentium’s 58W. Despite the Atom’s lower power draw, its newer architecture delivers superior multi-threaded performance and better instruction handling, as seen in its 65.4% encryption win and 38.3% extended instructions lead. The Pentium’s higher clock speed and dual-channel memory interface give it an edge in latency-sensitive single-thread tasks, but the Atom’s modern design makes it the more balanced performer across the benchmark suite. The market segments also differ: the Pentium is a desktop part, while the Atom is aimed at mobile applications, which explains the BGA socket and lower TDP.