AMD EPYC 7551 vs Intel Atom x7405C Comparison

Where Each One Wins

The benchmark data splits cleanly along workload type, but not in the way the core counts might suggest. The AMD EPYC 7551 wins every single head-to-head benchmark recorded between these two processors. The Intel Atom x7405C does not record a single win in the shared test suite. That said, the two chips are built for entirely different environments, and the data reflects that positioning rather than any kind of close competition.

The Atom x7405C is a 4-core, 4-thread mobile processor with a 12 W TDP. Its entire design philosophy centers on efficiency and modest workloads. The recorded scores show it is fully capable of handling lightweight tasks, but its performance envelope sits far below the EPYC 7551. In the PassMark suite, which is not part of the head-to-head comparison but is recorded for the Atom, the chip posts scores like 14,669 in integer math and 9,063 in floating point math. Those are respectable numbers for a low-power part, but they exist in a different performance class entirely from the EPYC.

The EPYC 7551 is a 32-core, 64-thread server processor with a 180 W TDP. It is designed for heavy parallel workloads, virtualization, database work, and anything that can spread across many threads. The Cinebench results demonstrate this clearly. In Cinebench R23 multicore, the EPYC scores 22,096 against the Atom's 4,435. That is a roughly 80% advantage. The single-core results also favor the EPYC, which is notable because single-thread performance is often where smaller, newer chips can close the gap. Here, the EPYC's older Zen architecture still manages to outrun the Atom's Gracemont cores in every recorded single-thread test.

The use-case split is therefore straightforward. The Atom x7405C wins in scenarios where power draw, physical footprint, and thermal output are the primary constraints. The EPYC 7551 wins in scenarios where raw throughput matters more than efficiency. If the workload is a lightweight container, an edge gateway, or a fanless embedded system, the Atom is the appropriate choice. If the workload is a dense virtualization host, a database server, or a batch processing node, the EPYC is the only sensible option. The 62nd percentile ranking for both chips in the database's global CPU standings reinforces this: they are not competing for the same socket, the same platform, or the same buyer.

FAQ

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

A: The AMD EPYC 7551 wins all multi-threaded Cinebench tests by a wide margin. In Cinebench R23 multicore, it scores 22,096 compared to the Atom x7405C's 4,435, a difference of roughly 80%.

Q: Does the Intel Atom x7405C win any benchmark in the head-to-head comparison?

A: No. The recorded head-to-head data shows zero wins for the Atom x7405C. The EPYC 7551 wins all six Cinebench tests, both single-core and multi-core.

Q: Is the EPYC 7551 also faster in single-core performance?

A: Yes. Despite being an older architecture, the EPYC 7551 scores 3,119 in Cinebench R23 single-core against the Atom's 626. The margin is approximately 80% in favor of the EPYC in every single-core test.

Q: What is the memory configuration difference?

A: The Atom x7405C uses single-channel memory with a maximum bandwidth of 38.4 GB/s and supports both DDR4 and DDR5. The EPYC 7551 uses eight-channel memory with a maximum bandwidth of 170.6 GB/s and supports DDR4 only.

Q: Which processor supports ECC memory?

A: Only the AMD EPYC 7551 supports ECC memory. The Intel Atom x7405C does not have ECC support.

Q: How do their global performance percentiles compare?

A: Both processors sit at the 62nd percentile in the database's ranking of all CPUs. The Atom has an average benchmark score of 6,568, while the EPYC has an average benchmark score of 6,391.

Head-to-Head Benchmarks

The head-to-head results are one-sided, and the margins are consistent across every test. In Cinebench R15 multicore, the EPYC 7551 scores 2,227 against the Atom's 446, a delta of -80%. The single-core R15 test shows the same pattern: 314 for the EPYC versus 62 for the Atom, a delta of -80.3%.

Moving to Cinebench R20, the EPYC scores 9,280 in multicore against the Atom's 1,862, a delta of -79.9%. The single-core R20 result is 1,309 against 262, a delta of -80%. Cinebench R23 follows the identical trend. The EPYC posts 22,096 in multicore versus the Atom's 4,435, and 3,119 in single-core versus 626. Both deltas sit at -79.9%.

The consistency of these margins is remarkable. Every single test, regardless of whether it stresses one core or all available cores, lands at approximately an 80% deficit for the Atom. This suggests the performance gap is not a matter of scaling or thread count, but rather a fundamental difference in per-core throughput and clock behavior. The EPYC has a base clock of 2.00 GHz and a boost of 3.00 GHz. The Atom has a base of 1.70 GHz and a boost of 3.40 GHz. The Atom's higher boost clock does not translate into a single-core advantage. The EPYC's Zen cores simply deliver more instructions per clock in these workloads.

The only additional data available for the Atom comes from the PassMark suite, where it records scores that are not part of the head-to-head table. Those include 56,317 in data compression, 4,004 in data encryption, and 5,218 in multithreaded performance. These numbers give a sense of the Atom's standalone capabilities, but they cannot be compared directly to the EPYC because the EPYC has no recorded PassMark results in the database.

For anyone evaluating these two chips, the head-to-head data is unambiguous. The EPYC 7551 is faster in every measured category, and the margin is consistently around 80%. The Atom x7405C is not competitive in raw performance, and it was never designed to be. Its role is defined by power efficiency and platform integration, not by winning benchmark comparisons against server-class silicon.

Specification Differences

The specification gap between these two processors is as wide as the benchmark gap. The Atom x7405C has 4 cores and 4 threads. The EPYC 7551 has 32 cores and 64 threads. That is an 8x difference in core count and a 16x difference in thread count, and it explains the bulk of the multicore performance delta.

Clock speeds differ in both directions. The Atom has a base clock of 1.70 GHz and a boost clock of 3.40 GHz. The EPYC has a base clock of 2.00 GHz and a boost clock of 3.00 GHz. The Atom boosts higher, but the EPYC starts from a higher base. In practice, the EPYC still wins single-core tests, which indicates that raw clock speed is not the deciding factor.

Thermal design power is another major differentiator. The Atom is rated at 12 W, while the EPYC is rated at 180 W. That is a 15x difference in power envelope, and it reflects the fundamental design goals of each chip. The Atom is built for low-power mobile and embedded environments. The EPYC is built for server racks with robust cooling and power delivery.

The sockets are incompatible. The Atom uses Intel BGA 1264, a soldered mobile socket. The EPYC uses AMD Socket SP3, a server socket designed for replaceable processors. The Atom is a mobile part, while the EPYC is a server and workstation part. The market segments confirm this: the Atom is listed under Mobile, and the EPYC under Server/Workstation.

Memory support also diverges sharply. The Atom supports DDR4 and DDR5 in a single-channel configuration, with a maximum memory bandwidth of 38.4 GB/s. The EPYC supports DDR4 only, but in an eight-channel configuration, with a maximum memory bandwidth of 170.6 GB/s. The EPYC also supports ECC memory; the Atom does not.

PCIe support differs as well. The Atom offers PCIe Gen 3 with 9 lanes (CPU only). The EPYC offers PCIe Gen 3 without a lane count listed in the database. The EPYC has an unlocked multiplier, while the Atom does not. The Atom has no integrated graphics, and the EPYC's integrated graphics field is null.

The release dates are separated by nearly seven years. The EPYC 7551 was released on June 28, 2017. The Atom x7405C was released on April 7, 2024. The Atom's launch MSRP is $57, but the EPYC has no recorded launch MSRP in the database.

Architecture Differences

The architectural story is a clash of two very different design philosophies separated by several process generations. The Intel Atom x7405C uses the Amston Lake architecture, built on a 10 nm process at Intel. Its cores are Gracemont, which are Intel's efficiency-focused core design. The chip is part of the Atom generation and carries the Gracemont microarchitecture label. The process node is 10 nm, and the foundry is Intel itself.

The AMD EPYC 7551 uses the Zen architecture, built on a 14 nm process at GlobalFoundries. The codename is Naples, and it belongs to the EPYC 7001 series. The chip is part of the EPYC generation with the Zen (Naples) microarchitecture. The process node is 14 nm, which is older and less dense than Intel's 10 nm node. The EPYC does have recorded transistor and die size data: 4,800 million transistors on a 213 mm² die. The Atom has no recorded transistor count or die size in the database.

Cache configurations differ in structure and capacity. Both chips have 96 KB of L1 cache per core. The L2 cache is where the designs diverge. The Atom has 2 MB of shared L2 cache, while the EPYC has 512 KB of L2 cache per core. With 32 cores, the EPYC's total L2 cache is substantially larger, but it is distributed per core rather than shared. The L3 cache shows an even bigger gap. The Atom has 6 MB of shared L3 cache. The EPYC has 64 MB of shared L3 cache, more than ten times the Atom's total.

The memory controllers reflect the target markets. The Atom's single-channel memory bus and 38.4 GB/s bandwidth are adequate for low-power mobile workloads. The EPYC's eight-channel memory bus and 170.6 GB/s bandwidth are designed for memory-intensive server workloads. The lack of ECC support on the Atom further separates it from the EPYC, which includes ECC as a standard feature.

The transistor and process differences tell a story of time and purpose. The EPYC was built on a mature 14 nm process with a massive transistor budget devoted to 32 high-performance Zen cores. The Atom was built on Intel's 10 nm process with a far smaller transistor budget, devoted to 4 efficiency-focused Gracemont cores. The 10 nm process gives the Atom a density advantage per transistor, but the EPYC's sheer scale overwhelms that advantage in every recorded benchmark.

The production status for both chips is listed as Active, meaning both remain in production. The Atom's part number is SRNEM, and the EPYC's part number is PS7551BDVIHAF. Neither chip has a 3D V-Cache variant recorded in the database.

In summary, the Atom x7405C is a modern, efficient, low-power processor built for mobile and embedded roles. The EPYC 7551 is an older, power-hungry, massively parallel server processor. The architecture gap is not close, and the benchmark data reflects it. The Atom's newer process node and higher boost clock cannot compensate for the EPYC's enormous advantage in cores, cache, memory bandwidth, and per-core Zen performance.