Quick verdict
The AMD FX-8350 is the right upgrade target for most AM3+ boards - its 125W TDP is widely supported, its eight-core performance handles modern light workloads, and used units are inexpensive. For AM3 non-plus motherboards, the Phenom II X6 1100T remains the definitive top chip. Before spending on an AM3+ upgrade, evaluate whether a used Ryzen platform would serve you better for the same cost.
Top 5 Picks
| CPU | Cores/Threads | Base/Boost Clock | TDP | Best For | |---|---|---|---|---| | [AMD FX-8350](https://www.amazon.com/s?k=AMD+FX-8350&tag=thetestedhub-20) | 8C/8T | 4.0 / 4.2 GHz | 125W | Best overall AM3+ CPU | | [AMD FX-8320](https://www.amazon.com/s?k=AMD+FX-8320&tag=thetestedhub-20) | 8C/8T | 3.5 / 4.0 GHz | 125W | Best value 8-core AM3+ | | [AMD FX-6350](https://www.amazon.com/s?k=AMD+FX-6350&tag=thetestedhub-20) | 6C/6T | 3.9 / 4.2 GHz | 125W | Best mid-range AM3+ | | [AMD Phenom II X6 1100T](https://www.amazon.com/s?k=AMD+Phenom+II+X6+1100T&tag=thetestedhub-20) | 6C/6T | 3.3 / 3.7 GHz | 125W | Best AM3 (non-plus) CPU | | [AMD FX-9590](https://www.amazon.com/s?k=AMD+FX-9590&tag=thetestedhub-20) | 8C/8T | 4.7 / 5.0 GHz | 220W | Fastest AM3+ at any cost |
Check price on Amazon →Best CPUs for AM3 and AM3+ socket builds in 2026. If you are upgrading an older AMD platform, these processors deliver the best performance your board can support without a full rebuild.
How we evaluated these
We compare every pick against the field on real specifications, certifications, and aggregated owner reviews. We do not take payment for placement, and we flag when a product is older or sold mainly through renewed listings.
The shortlist
| Pick | Best for | Score | |
|---|---|---|---|
| Top 5 Picks | Check price |
Each pick, examined
Top 5 Picks
| CPU | Cores/Threads | Base/Boost Clock | TDP | Best For | |---|---|---|---|---| | [AMD FX-8350](https://www.amazon.com/s?k=AMD+FX-8350&tag=thetestedhub-20) | 8C/8T | 4.0 / 4.2 GHz | 125W | Best overall AM3+ CPU | | [AMD FX-8320](https://www.amazon.com/s?k=AMD+FX-8320&tag=thetestedhub-20) | 8C/8T | 3.5 / 4.0 GHz | 125W | Best value 8-core AM3+ | | [AMD FX-6350](https://www.amazon.com/s?k=AMD+FX-6350&tag=thetestedhub-20) | 6C/6T | 3.9 / 4.2 GHz | 125W | Best mid-range AM3+ | | [AMD Phenom II X6 1100T](https://www.amazon.com/s?k=AMD+Phenom+II+X6+1100T&tag=thetestedhub-20) | 6C/6T | 3.3 / 3.7 GHz | 125W | Best AM3 (non-plus) CPU | | [AMD FX-9590](https://www.amazon.com/s?k=AMD+FX-9590&tag=thetestedhub-20) | 8C/8T | 4.7 / 5.0 GHz | 220W | Fastest AM3+ at any cost |
Buying considerations
What to consider
Check your motherboard's CPU support list first. Not all AM3+ boards support all FX-series chips - some 970 chipset boards cap out at 95W TDP CPUs, which excludes the FX-8350, FX-8320, and FX-9590. Only 990FX boards reliably support 125W and 220W processors.
What to consider
Buy used for AM3+ upgrades. These CPUs are no longer in production, but the used market on eBay and local marketplaces offers clean FX-8350 and Phenom II X6 units at low prices. Verify the chip has no bent pins and inspect photos carefully before purchasing.
What to consider
Consider a cooler upgrade alongside the CPU. The stock AMD coolers shipped with FX-series chips are inadequate for sustained loads on 125W TDP processors. A budget air cooler from Cooler Master or be quiet! will significantly improve stability and longevity.
Final word
The AMD FX-8350 is the right upgrade target for most AM3+ boards - its 125W TDP is widely supported, its eight-core performance handles modern light workloads, and used units are inexpensive. For AM3 non-plus motherboards, the Phenom II X6 1100T remains the definitive top chip. Before spending on an AM3+ upgrade, evaluate whether a used Ryzen platform would serve you better for the same cost.
Questions answered
The AMD FX-8350 and FX-9590 are the highest-performing CPUs available for AM3+ motherboards. The FX-8350 offers the best balance of performance and power consumption at 125W TDP. The FX-9590 is the fastest AM3+ chip but requires a motherboard rated for its 220W TDP and a robust CPU cooler. For AM3 non-plus boards, the Phenom II X6 1100T remains the fastest compatible option and runs cooler than FX-series chips.
For light tasks like web browsing, media playback, and office work, upgrading an AM3+ build is worthwhile if the rest of the system is functional. For gaming, the AM3+ platform is significantly behind modern equivalents - even a used Ryzen 5 3600 on B450 will deliver dramatically better gaming performance. If budget allows, a platform upgrade to AM4 or AM5 is the better long-term move. AM3+ upgrades make most sense when a complete rebuild is not financially feasible.
AM3 CPUs are backward compatible with AM3+ motherboards in most cases, though performance may be limited by the board's voltage delivery capabilities. AM3+ CPUs are not compatible with AM3 motherboards due to power delivery and signalling differences. Always verify compatibility using your motherboard manufacturer's CPU support list before purchasing. Some AM3+ boards require a BIOS update to support FX-series chips, which may require temporarily installing an older AM3 CPU to perform the update.
Tom Reeves has reviewed consumer electronics for over a decade, with a focus on televisions, monitors, laptops, and smart home devices. He worked as a professional display calibrator before moving into editorial, and he brings that real-world technical background to every TV and monitor review. At TheTestedHub, Tom covers display calibration, computer monitors, laptops and 2-in-1s, smart home platforms, home theater setups, and HDR performance.
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