Best B450 Motherboards: Top AM4 Value Picks
B450 remains a staple of ultra-budget PC building. We break down the best B450 motherboards worth buying on the used market and clearance racks.
The Best B450 Motherboards: Quick Picks
If you are buying a B450 motherboard today, you are hunting for an ultra-budget secondhand deal or building a low-cost rig around a used Ryzen 3000 or 5000 chip. Never spend over $80 on a brand-new B450 board when modern B550 options often sit right next to them in price.
- Best Overall: MSI B450 Tomahawk Max
- Best Features & Wi-Fi: MSI B450 Gaming Pro Carbon AC
- Best Micro-ATX: ASRock B450M Pro4
- Best Ultra-Budget: Gigabyte B450M DS3H V2
- Best Mini-ITX: ASUS ROG Strix B450-I Gaming
Does a B450 Board Still Make Sense?
AMD launched the B450 chipset back in 2018 alongside Zen+ (Ryzen 2000). Thanks to AMD's long-term AM4 support, nearly every B450 board received BIOS updates to run Ryzen 3000 and Ryzen 5000 CPUs, including the Ryzen 7 5700X3D and 5800X3D. That extended lifespan turned B450 into one of the best budget platforms in DIY PC history.
That said, B450 is strictly a PCIe 3.0 platform. You will not get PCIe 4.0 storage speeds or the full bandwidth for modern budget GPUs wired with only x4 or x8 lanes (like the RX 6500 XT or RTX 4060). On the used market for $40 to $65, a solid B450 board paired with a cheap Ryzen 5 3600 or 5600 makes absolute financial sense. If retailers try charging you $90 or more, walk away and grab a B550 board instead.
B450 Motherboard Comparison
| Motherboard | Form Factor | VRM Layout | M.2 Slots | Ideal CPU Pairing |
|---|---|---|---|---|
| MSI B450 Tomahawk Max | ATX | 4+2 (Doubled components) | 1x PCIe 3.0 x4 | Ryzen 5 5600 / Ryzen 7 5700X3D |
| MSI B450 Gaming Pro Carbon AC | ATX | 4+2 (Doubled components) | 2 (1x Gen3 x4, 1x Gen2 x4) | Ryzen 7 5700X / 5800X |
| ASRock B450M Pro4 | Micro-ATX | 3+3 (6-phase core) | 2 (1x Gen3 x4, 1x SATA) | Ryzen 5 3600 / 5500 / 5600 |
| Gigabyte B450M DS3H V2 | Micro-ATX | 4+2 (Basic discrete) | 1x PCIe 3.0 x4 | Ryzen 3 3100 / Ryzen 5 3600 / 5500 |
| ASUS ROG Strix B450-I Gaming | Mini-ITX | 6+1 (Integrated power stages) | 2 (Dual M.2 via riser/back) | Ryzen 5 5600 / 5700X |
Top 5 B450 Motherboards Tested & Ranked
1. MSI B450 Tomahawk Max — Best Overall B450 Board
The MSI B450 Tomahawk Max is the defining AM4 motherboard of its generation. MSI nailed the fundamentals: massive heatsinks, capable power delivery, and a clean layout. The "Max" revision upgraded the BIOS ROM from 16MB to 32MB, ensuring full support for Ryzen 5000 CPUs without stripping away the graphical Click BIOS 5 interface.
Its 4+2 phase VRM with doubled components easily handles 65W and 105W CPUs without thermal throttling. You also get MSI's Flash BIOS Button on the rear I/O, allowing you to update firmware with just a USB drive and power supply—no old CPU required. The only real limitation is storage: you get only one M.2 NVMe slot.
2. MSI B450 Gaming Pro Carbon AC — Best Feature Set
If you want a B450 board that feels closer to an X470 flagship, the B450 Gaming Pro Carbon AC is the one to target on the used market. It shares the Tomahawk's excellent VRM design but adds an Intel Dual Band Wireless-AC 9260 card, Intel Gigabit LAN, upgraded Realtek ALC1220 audio, and a secondary M.2 slot.
The secondary M.2 slot runs at PCIe 2.0 x4 speeds, which cuts throughput in half compared to Gen3, but it gives you extra storage flexibility that the Tomahawk lacks. If you find one used for under $75, it is an outstanding anchor for a budget gaming setup.
3. ASRock B450M Pro4 — Best Budget Micro-ATX
For compact builds, the ASRock B450M Pro4 remains our favorite budget workhorse. Unlike many entry-level micro-ATX boards that cut corners, ASRock included four DDR4 RAM slots, two M.2 slots (one PCIe 3.0 x4, one SATA-only), USB Type-C on the rear panel, and proper VRM heatsinks across both the VCore and SoC phases.
Don't try running an overclocked 12-core chip on it, but for a 65W Ryzen 5 3600 or Ryzen 5 5600, it stays cool and stable. Used units routinely sell for $45 to $55, making it an incredible bargain for sub-$400 gaming rigs.
4. Gigabyte B450M DS3H V2 — Best Ultra-Low-Budget Board
The Gigabyte B450M DS3H V2 is built for one purpose: keeping component costs as low as humanly possible while still running standard desktop hardware. The V2 revision slightly improved the VRM controller, but the board remains barebones. The heatsink over the VCore is small, and the SoC rail is completely uncooled.
We recommend sticking to 65W 6-core processors like the Ryzen 5 3600 or Ryzen 5 5500. Avoid putting a high-wattage chip like the 5800X or 5900X in this board, as VRM temperatures will climb under heavy multi-threaded workloads. If every dollar counts, it gets the job done.
5. ASUS ROG Strix B450-I Gaming — Best Mini-ITX
Small form factor builds often carry a steep price tag, but the ASUS ROG Strix B450-I Gaming proved that Mini-ITX AM4 builds did not require expensive X-series chipsets. It features high-quality integrated power stages (6+1 phase using 50A Vishay MOSFETs) capable of powering higher-tier 8-core CPUs comfortably.
ASUS implemented an innovative audio/M.2 combo daughtercard on the front of the board, paired with a second M.2 slot on the back. It also includes onboard Intel Wi-Fi and SupremeFX S1220A audio. It remains one of the best choices for compact budget builds if you find one secondhand.
Buying a B450 Board Used? Watch Out for These 3 Traps
Buying legacy hardware requires caution. Keep these points in mind before handing over cash:
- Check the BIOS chip size: Non-"MAX" MSI boards and early B450 revisions used 16MB BIOS chips. While they support Ryzen 5000 via beta "GSE-Lite" BIOS updates, they lose RAID support and visual UI polish. Boards with 32MB chips provide a smoother experience.
- Look for BIOS Flashback: If you buy a B450 board that has been sitting in a closet since 2019, it won't boot with a Ryzen 5000 CPU installed until you update the firmware. Boards with a physical rear Flashback button let you update without borrowing an older Ryzen 1000/2000 CPU.
- PCIe Lane Sharing: B450 has limited chipset PCIe lanes. On many boards, populating a second M.2 slot or specific PCIe x1 slots will disable two of your SATA ports. Always double-check the motherboard manual before hooking up multiple hard drives.
FAQ
Does a B450 motherboard support AMD Ryzen 5000 processors?
Yes. Almost all major B450 motherboards received AGESA ComboV2 1.2.0.7 (or newer) BIOS updates to support Ryzen 5000 series processors, including the 5600, 5700X, and 5700X3D. You must ensure the board has an updated BIOS installed before it will post with a 5000-series chip.
Is PCIe 3.0 on B450 fast enough for modern gaming?
For most graphics cards running over full x16 lanes (like the RTX 3060, RTX 3070, or RX 6700 XT), PCIe 3.0 results in less than a 2-3% performance loss compared to PCIe 4.0. However, budget GPUs that are limited to PCIe 4.0 x4 lanes (such as the RX 6500 XT) will suffer noticeable frame drops on PCIe 3.0 slots.
What is the difference between B450 and B450M?
The "M" designates the Micro-ATX form factor (e.g., B450M Pro4 vs. B450 Tomahawk). Micro-ATX boards are shorter (244mm x 244mm vs. 305mm x 244mm), usually have fewer PCIe expansion slots, and occasionally offer fewer M.2 or fan headers. Chipset performance and CPU compatibility remain identical.