The AM4 board shortlist
The best AM4 motherboard in the UK, October 2026: ASUS ROG Strix B550-A Gaming, Gigabyte B550 Eagle WiFi6 and ASUS Prime boards, with Ryzen 5000 pairings.
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At a glance
The ASUS ROG Strix B550-A Gaming is the best AM4 motherboard in the UK, at £119.99 on Amazon UK at the time of writing (October 2026). ASUS lists a PCIe 4.0 x4 M.2 slot, six SATA ports, 2.5Gb Ethernet and BIOS FlashBack. The Gigabyte B550 Eagle WiFi6 at £88.99 is the value pick, and the ASUS Prime A520M-K at £48.98 is the cheapest board that runs a Ryzen 5000 chip. Buyers weighing AM4 against newer sockets will find the AM5 field in Best motherboard for gaming UK 2026.
What should an AM4 motherboard have in 2026?
A B550 chipset, a BIOS that supports Ryzen 5000 and enough memory slots for the build. Every AM4 board takes DDR4 only, so the AM4 motherboard choice is narrower than on newer sockets. Four checks matter:
- Chipset. B550 adds PCIe 4.0 to the first M.2 slot and the graphics slot when a Ryzen 5000 or 3000 chip is fitted. ASUS lists the A520-based Prime A520M-K at PCIe 3.0 x4 for its single M.2 slot.
- CPU support. Ryzen 5000 chips work on A520 and B550 boards, and ASUS lists Ryzen 5000 and 5000 G-Series on the Prime A520M-K.
- Memory. ASUS lists 128 GB across 4 DDR4 slots on the B550 boards here and 64 GB across 2 slots on the Prime A520M-K.
- BIOS recovery. BIOS FlashBack updates the firmware from a USB drive with no CPU installed. Only the ROG Strix B550-A Gaming carries it of the four boards.
Buyers upgrading a decade-old build should read How to upgrade an old gaming PC in 2026 first, since a board swap often needs a new CPU and memory. Graphics cards are covered in Best graphics card UK 2026.
1. ASUS ROG Strix B550-A Gaming - best overall
ASUS ROG Strix B550-A Gaming specifications (ASUS)
- Socket: AM4, Ryzen 5000, 4000 G-Series and 3000
- Memory: up to 128 GB DDR4, 4,600 MT/s overclocked for Ryzen 5000
- Storage: 2 M.2 slots (PCIe 4.0 x4 and PCIe 3.0 x4), 6 SATA 6Gb/s ports
- Network: Intel I225-V 2.5Gb Ethernet, no Wi-Fi
- USB: 1 USB 3.2 Gen 2 Type-C and 5 Type-A on the rear panel
- BIOS FlashBack: button and LED on the rear panel
The ROG Strix B550-A Gaming is the AM4 board to buy when the build must last. The Amazon listing states 12+1 power stages, the most on the list, and six SATA ports leave room for mechanical drives. The FlashBack button makes it the safest board for a Ryzen 5000 upgrade on an unknown BIOS.
Compromises: the board has no Wi-Fi, so buyers needing wireless must add a card, and £119.99 is £31.00 more than the Gigabyte B550 Eagle WiFi6.
ASUS ROG Strix B550-A Gaming - pros and cons
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2. Gigabyte B550 Eagle WiFi6 - best value
Gigabyte B550 Eagle WiFi6 specifications (Gigabyte listing)
- Socket: AM4, Ryzen 5000 G-Series and 5000 supported
- Power: 10+3+1 phase VRM
- Storage: 1 PCIe 4.0 M.2 slot and 1 PCIe 3.0 M.2 slot, 4 SATA ports
- Network: 1GbE LAN, Wi-Fi 6
- Memory: 4 DDR4 slots, up to 3,200 MHz listed
- Form factor: ATX
The Gigabyte B550 Eagle WiFi6 is the sensible middle of the AM4 market. It undercuts the ROG Strix B550-A Gaming by £31.00 and adds Wi-Fi 6, which the ROG board omits. The cost is 1Gb Ethernet in place of 2.5Gb and no FlashBack button on the listing.
Gigabyte B550 Eagle WiFi6 - pros and cons
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3. ASUS Prime B550M-A WiFi II - best micro-ATX
ASUS Prime B550M-A WiFi II specifications (ASUS)
- Socket: AM4, Ryzen 5000, 5000 G-Series and 3000
- Memory: 4 DIMM slots, up to 128 GB DDR4, 4,866 MT/s overclocked
- Storage: 2 M.2 slots, 4 SATA 6Gb/s ports
- Network: Realtek 1Gb Ethernet, Wi-Fi 6 with Bluetooth 5.2
- USB: 6 Type-A ports on the rear panel, no Type-C
- Form factor: micro-ATX, 24.4 x 24.4 cm
The Prime B550M-A WiFi II suits small cases and sits £1.01 above the Gigabyte B550 Eagle WiFi6. ASUS lists CrashFree BIOS 3 and EZ Flash 3 for recovery rather than BIOS FlashBack, and the rear panel has no USB-C port. The board suits a micro-ATX build that needs Wi-Fi 6 and four memory slots.
ASUS Prime B550M-A WiFi II - pros and cons
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4. ASUS Prime A520M-K - best budget
ASUS Prime A520M-K specifications (ASUS)
- Socket: AM4, Ryzen 5000 and 5000 G-Series supported
- Memory: 2 DIMM slots, up to 64 GB DDR4, 3,200 MT/s without overclocking
- Storage: 1 M.2 slot (PCIe 3.0 x4 or SATA), 4 SATA 6Gb/s ports
- Network: Realtek RTL8111H 1Gb Ethernet, no Wi-Fi
- USB: 4 USB 3.2 Gen 1 and 2 USB 2.0 Type-A on the rear panel
- Form factor: micro-ATX, 22.6 x 22.1 cm
The Prime A520M-K is the cheapest AM4 board here at £48.98, and £40.01 less than the Gigabyte B550 Eagle WiFi6. It suits a Ryzen 5 5500 or Ryzen 5 5600G office build or a first PC. Its limits are one M.2 slot, two memory slots and PCIe 3.0 storage, and ASUS points buyers to its site for the latest BIOS.
ASUS Prime A520M-K - pros and cons
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Radar · 0-100 scores
- ASUS ROG Strix B550-A Gaming
- Gigabyte B550 Eagle WiFi6
- ASUS Prime B550M-A WiFi II
- ASUS Prime A520M-K
Best AM4 motherboard: spec sheet
| Spec | ROG Strix B550-A | B550 Eagle WiFi6 | Prime B550M-A WiFi II | Prime A520M-K |
|---|---|---|---|---|
| Price (Amazon UK) | £119.99 | £88.99 | £89.99 | £48.98 |
| Chipset | B550 | B550 | B550 | A520 |
| Form factor | ATX | ATX | Micro-ATX | Micro-ATX |
| DIMM slots and limit | 4, 128 GB | 4, not stated | 4, 128 GB | 2, 64 GB |
| M.2 slots | 2 (one PCIe 4.0) | 2 (one PCIe 4.0) | 2 (one PCIe 4.0) | 1 (PCIe 3.0) |
| SATA ports | 6 | 4 | 4 | 4 |
| Ethernet | 2.5Gb | 1Gb | 1Gb | 1Gb |
| Wi-Fi | None | Wi-Fi 6 | Wi-Fi 6 | None |
| BIOS FlashBack | Yes | Not listed | Not listed | Not listed |
What does the extra money buy on an AM4 motherboard?
The first £40.01 buys the jump from A520 to B550, and that is the best money in the field. Compare Electronic set each board against the cheapest, the ASUS Prime A520M-K, at Amazon UK prices.
| Board | Price | Premium over cheapest | What the extra buys |
|---|---|---|---|
| ASUS Prime A520M-K | £48.98 | Baseline | Ryzen 5000 support, one PCIe 3.0 M.2 slot, 1Gb LAN |
| Gigabyte B550 Eagle WiFi6 | £88.99 | +£40.01 | B550, a PCIe 4.0 M.2 slot, a second M.2 slot, Wi-Fi 6, full ATX |
| ASUS Prime B550M-A WiFi II | £89.99 | +£41.01 | B550, two M.2 slots, 128 GB DDR4 limit, Wi-Fi 6 with Bluetooth 5.2 |
| ASUS ROG Strix B550-A Gaming | £119.99 | +£71.01 | BIOS FlashBack, 2.5Gb LAN, six SATA ports, USB-C, 12+1 power stages |
The next £31.00 from the Gigabyte B550 Eagle WiFi6 to the ASUS ROG Strix B550-A Gaming swaps Wi-Fi 6 for BIOS FlashBack, 2.5Gb Ethernet and two more SATA ports. Buyers who never plug in more than two drives gain little from the upgrade, while buyers who want a recovery path for a Ryzen 5000 swap gain a lot.
Which Ryzen 5000 chip suits an AM4 board? Ryzen 5 5500 and 5600G prices
The Ryzen 5 5600X is the pairing to beat: Amazon UK lists it at £146.99 with 6 cores, 12 threads, 65 W, 35 MB of cache and a 4.6 GHz boost. The Ryzen 5 5500 is £51.99 cheaper at £95.00 and lists 19 MB of cache and a 4.2 GHz boost, 16 MB and 0.4 GHz less. The Ryzen 5 5600G lists integrated Radeon graphics and a 4.4 GHz boost at £174.99, £28.00 above the 5600X, so it pays only for buyers who skip a graphics card.
| Pairing | Parts | Total | Suits |
|---|---|---|---|
| Ryzen 5 5500 + ASUS Prime A520M-K | £95.00 + £48.98 | £143.98 | Cheapest gaming base; needs a graphics card |
| Ryzen 5 5600G + ASUS Prime A520M-K | £174.99 + £48.98 | £223.97 | No graphics card needed for a first build |
| Ryzen 5 5600X + Gigabyte B550 Eagle WiFi6 | £146.99 + £88.99 | £235.98 | Best value gaming pairing |
| Ryzen 7 5700X + ASUS Prime B550M-A WiFi II | £169.99 + £89.99 | £259.98 | Eight cores in a small case |
| Ryzen 5 5600X + ASUS ROG Strix B550-A Gaming | £146.99 + £119.99 | £266.98 | Sturdiest board for a long-lived build |
One PCIe detail applies to the 5600G. ASUS lists the first M.2 slot of the Prime B550M-A WiFi II at PCIe 4.0 x4 with Ryzen 5000 and 3000 chips and PCIe 3.0 x4 with 5000 G-Series chips, so a 5600G build gets no PCIe 4.0 storage. Buyers adding a drive should see Best NVMe SSD for gaming UK 2026.
Does an AM4 board need a BIOS update, and what is BIOS FlashBack?
Boards released before Ryzen 5000 can need a newer BIOS before a 5000-series chip will start. BIOS FlashBack is the fix: a USB drive holding the new BIOS file is plugged into a marked port and a button on the rear panel is pressed, with no CPU or memory fitted. ASUS fits the button to the ROG Strix B550-A Gaming, and its spec pages for the Prime B550M-A WiFi II and Prime A520M-K list CrashFree BIOS 3 and EZ Flash 3 instead, which run from inside the BIOS and need a CPU that boots. The ASUS page for the Prime A520M-K tells buyers to check its site for the latest updates before fitting a newer chip.
A buyer with an older Ryzen 3000 chip in hand can update first and swap the CPU second. A buyer starting with a Ryzen 5000 chip should choose the FlashBack board or confirm the BIOS version with the seller. Power draw advice for the upgrade is in How many watts PSU do I need?
Who should skip an AM4 motherboard?
Buyers starting a new build with no DDR4 memory to reuse should skip AM4, because the socket takes DDR4 only and offers no newer processors. The AMD Ryzen 5 9600X lists on Amazon UK at £160.97, £13.98 above the Ryzen 5 5600X at £146.99, before the cost of an AM5 board and DDR5 memory. The AM4 route pays back for a buyer who already owns DDR4 or a Ryzen 3000 chip and wants a cheap lift in performance: a Ryzen 5 5600X on a £88.99 board costs £235.98 in total. Buyers choosing between the two can compare the AM5 field in Best CPU for gaming UK 2026.
Verdict
The ASUS ROG Strix B550-A Gaming at £119.99 is the best AM4 motherboard for a build that must last, and the Gigabyte B550 Eagle WiFi6 at £88.99 is the better buy for most gaming PCs. The ASUS Prime B550M-A WiFi II at £89.99 fits small cases, and the ASUS Prime A520M-K at £48.98 covers the cheapest Ryzen 5000 route. Buyers starting from scratch should compare against Best motherboard for gaming UK 2026 before committing to a socket with DDR4 only.
Frequently asked questions
What is the best AM4 motherboard?
The ASUS ROG Strix B550-A Gaming, at £119.99 on Amazon UK at the time of writing (October 2026). ASUS lists a PCIe 4.0 x4 M.2 slot, six SATA ports, 2.5Gb Ethernet and a back-panel BIOS FlashBack button. Buyers on a tighter budget get a B550 board with Wi-Fi 6 in the Gigabyte B550 Eagle WiFi6 at £88.99.
Is an AM4 motherboard still worth buying in 2026?
Yes, for an upgrade of an existing Ryzen build or a budget build on DDR4 memory. A Ryzen 5 5600X (£146.99) and a Gigabyte B550 Eagle WiFi6 (£88.99) cost £235.98 together on Amazon UK in October 2026. New builds that want a long upgrade path should look at AM5 boards instead.
Do AM4 motherboards need a BIOS update for Ryzen 5000?
Some do. Boards designed before Ryzen 5000 can need a newer BIOS, and ASUS tells buyers of the Prime A520M-K to check its site for the latest update. The ASUS ROG Strix B550-A Gaming has a BIOS FlashBack button on the rear panel, which updates the BIOS from a USB drive without a working CPU.
How much does a Ryzen 5 5600G cost?
Amazon UK listed the AMD Ryzen 5 5600G at £174.99 on 16 October 2026, which is £28.00 more than the Ryzen 5 5600X at £146.99. The 5600G has 6 cores, 12 threads, integrated Radeon graphics and a Wraith Stealth cooler, so it removes the need for a graphics card in a first build.
Is the Ryzen 5 5500 any good for an AM4 build?
It is the cheapest sensible AM4 gaming chip. The Amazon UK listing gives the Ryzen 5 5500 6 cores, 12 threads, 65 W, 19 MB of cache and a 4.2 GHz boost, at £95.00. The Ryzen 5 5600X lists 35 MB of cache and a 4.6 GHz boost for £51.99 more.
Does a B550 board have PCIe 4.0?
Yes, with a Ryzen 5000 or 3000 processor. ASUS lists the first M.2 slot of the Prime B550M-A WiFi II as PCIe 4.0 x4 with Ryzen 5000 and 3000 chips and PCIe 3.0 x4 with 5000 G-Series chips such as the Ryzen 5 5600G. A520 boards such as the ASUS Prime A520M-K stop at PCIe 3.0.
Can an AM4 motherboard use DDR5 memory?
No. AM4 boards take DDR4 only, and DDR5 needs an AM5 board. The ASUS Prime A520M-K has 2 DIMM slots and a 64 GB limit, the ASUS Prime B550M-A WiFi II 4 slots and 128 GB. ASUS lists DDR4 up to 3,200 MT/s without overclocking on the A520 board.