AMD Athlon PRO 3045B vs AMD Athlon X4 840

For users prioritizing power efficiency and modern integration, the AMD Athlon PRO 3045B stands out as a compelling choice, while the Athlon X4 840 remains relevant for budget desktops where raw single-core performance is still valued. As of April 2026, the Athlon PRO 3045B is a relatively recent processor, released in the early 2020s, whereas the Athlon X4 840 dates back to 2014, making it a nearly decade-old design. Despite its age, the X4 840 still holds a place in entry-level builds due to its higher clock speed, but its outdated 28 nm manufacturing process and lack of modern features limit its long-term viability.

The Athlon PRO 3045B is built on a 14 nm process, which allows for a significantly lower 15 W TDP compared to the X4 840’s 65 W. This makes the PRO 3045B ideal for thin-and-light systems or small form-factor PCs where thermal constraints are critical. In contrast, the X4 840’s higher power draw reflects its older design and lack of energy-efficient optimizations, making it better suited for desktops with robust cooling and consistent power delivery.

In terms of core count, both processors are quad-core, but the Athlon PRO 3045B benefits from a more advanced microarchitecture—Dali—compared to the Kaveri architecture used in the X4 840. The PRO 3045B also features a larger L3 cache at 3.815 MiB versus the X4 840’s undisclosed but likely smaller cache, which contributes to its superior overall performance. The PRO 3045B achieves an overall Passmark score of 4580, ranking #1207 of 2060, while the X4 840 scores 4431, placing it at #1358.

Despite the PRO 3045B’s higher overall score, the Athlon X4 840 performs slightly better in single-core tasks, with a single-core score of 4429 versus the PRO 3045B’s 4677. However, the PRO 3045B’s multicore score of 4434 matches the X4 840’s 4435, indicating that while the X4 840 holds a slight edge in single-threaded workloads due to its higher clock speed, the PRO 3045B compensates with more efficient core design and better cache utilization.

For users needing modern instruction set support, the PRO 3045B offers a broader range of extensions, including AVX2, BMI2, and FMA3, which are essential for modern software and virtualization tasks. The X4 840, while supporting many older instruction sets like SSE4.2 and AVX, lacks the newer features and includes legacy technologies such as 3DNow! and XOP, which are no longer widely used.

In conclusion, the Athlon PRO 3045B excels in efficiency, modern compatibility, and overall balanced performance, making it suitable for light productivity, web browsing, and virtualization. The Athlon X4 840, while outdated, remains a viable option for basic computing tasks in older systems, but its high power consumption and lack of modern features limit its appeal. For most users in 2026, the PRO 3045B is the more forward-thinking and capable choice.