AM4 · Micro-ATX · DDR4 · board-only configuration · MSI global specification
A compact Micro-ATX AM4 motherboard with AMD A520: two DDR4 slots (up to 64 GB, DDR4-4600+ OC), a PCIe 3.0 x16 graphics slot, one M.2 slot and Realtek 1 Gb Ethernet.
Specifications checked 21 Sept 2026.
Amazon links open search results. Check the exact variant, current price and availability with the retailer.
Manufacturer specificationsAM4 · Micro-ATX · DDR4 · board-only configuration · MSI global specification
A compact Micro-ATX AM4 motherboard with AMD B450: two DDR4 slots (up to 64 GB, DDR4-4133 OC), a PCIe 3.0 x16 graphics slot, one M.2 slot and Realtek 8125BG 2.5 Gb Ethernet.
Specifications checked 21 Sept 2026.
Amazon links open search results. Check the exact variant, current price and availability with the retailer.
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Differences first. Select a topic for its graphic, sources and conditions.
Different hardware. A chip name or generation does not quantify real-world performance.
Plan the complete platform. Check the exact CPU-support list, required BIOS and memory validation before buying. PCIe generations and lane allocations can change with the processor. A socket match or slot count is not a guarantee that every component works together at its highest advertised setting.
11 verified differences, most decision-relevant first. 7 are also drawn in Visual facts above. Missing information stays separate.
Manufacturer specification
MSI B450M-A PRO MAX II — manufacturer specificationsDifferent hardware. A chip name or generation does not quantify real-world performance.
The overclocked speed is MSI's 1DPC 1R maximum; MSI lists 1DPC 2R up to 3866 MHz. JEDEC speeds run up to DDR4-3200. · Manufacturer specification · CPU, BIOS and validated DIMM population determine supported capacity and speeds. DDR4 and DDR5 are not interchangeable.
MSI A520M-A PRO — manufacturer specificationsManufacturer specification · CPU, BIOS and validated DIMM population determine supported capacity and speeds. DDR4 and DDR5 are not interchangeable.
MSI B450M-A PRO MAX II — manufacturer specificationsCheck the exact configuration and source conditions for your use.
The M.2 slot connects to the CPU. · Manufacturer specification · With Athlon processors with Radeon Vega Graphics the M.2 slot works in SATA mode only. It accepts 2242/2260/2280 drives.
MSI A520M-A PRO — manufacturer specificationsM2_1 connects to the CPU. · Manufacturer specification · M2_1 accepts 2280/2260/2242 drives.
MSI B450M-A PRO MAX II — manufacturer specificationsCheck the exact configuration and source conditions for your use.
Manufacturer specification · Electrical links and physical connectors are separate; no measured performance is inferred.
MSI B450M-A PRO MAX II — manufacturer specificationsCheck the exact configuration and source conditions for your use.
Manufacturer specification · Wired Ethernet only; MSI lists no Wi-Fi or Bluetooth hardware for this board.
MSI A520M-A PRO — manufacturer specificationsMSI's specification page lists a Realtek 8125 2.5 Gbps LAN controller and a 2.5G LAN rear port, and the model datasheet names the Realtek 8125BG. An older section of MSI's page that listed a Realtek 8111H Gigabit controller conflicts with both and no longer appears on the page. · Manufacturer specification · Wired Ethernet only; no Wi-Fi or Bluetooth module is listed for this board.
MSI B450M-A PRO MAX II — manufacturer specificationsMSI B450M-A PRO MAX II — exact model datasheetCheck the exact configuration and source conditions for your use.
Manufacturer specification · Manufacturer-listed onboard audio hardware, not a measured sound-quality result. Where alternatives are listed, no particular unseen controller revision is promised.
MSI A520M-A PRO — manufacturer specificationsManufacturer specification · Manufacturer-listed onboard audio hardware, not a measured sound-quality result. Where alternatives are listed, no particular unseen controller revision is promised.
MSI B450M-A PRO MAX II — manufacturer specificationsCheck the exact configuration and source conditions for your use.
Manufacturer specification · ECC modules run in non-ECC mode, so error correction is not active.
MSI A520M-A PRO — manufacturer specificationsManufacturer specification · ECC modules run in non-ECC mode, so error correction is not active.
MSI B450M-A PRO MAX II — manufacturer specificationsCheck the exact configuration and source conditions for your use.
Manufacturer specification · Requires a processor with integrated graphics; supported modes depend on the CPU.
MSI A520M-A PRO — manufacturer specificationsManufacturer specification · Requires integrated CPU graphics; supported modes depend on processor.
MSI B450M-A PRO MAX II — manufacturer specificationsCheck the exact configuration and source conditions for your use.
MSI labels these memory speeds in MHz (manufacturer notation); they are the rated data rates. · Manufacturer specification · Manufacturer A-XMP/OC limits, not guaranteed stability or measured performance. CPU, BIOS and memory-module compatibility apply.
MSI A520M-A PRO — manufacturer specificationsManufacturer specification · Manufacturer OC configurations, not guaranteed kit speed or measured application performance. CPU, BIOS, memory rank and DIMMs per channel determine support.
MSI B450M-A PRO MAX II — manufacturer specificationsCheck the exact configuration and source conditions for your use.
Manufacturer specification · x16 with Ryzen 5000/5000G/4000G/3000; x8 with Ryzen 3000G; x4 with Athlon with Radeon Graphics processors. Check the CPU support list for the exact processor.
MSI A520M-A PRO — manufacturer specificationsManufacturer specification · Not a measured graphics performance result.
MSI B450M-A PRO MAX II — manufacturer specificationsCheck the exact configuration and source conditions for your use.
Manufacturer specification · Internal-header capacity; requires compatible case ports and wiring. Not rear-panel sockets.
MSI A520M-A PRO — manufacturer specificationsManufacturer specification · Requires compatible case ports and cabling; not rear sockets.
MSI B450M-A PRO MAX II — manufacturer specificationsCheck the exact configuration and source conditions for your use.
Manufacturer specification · Check MSI's exact CPU support list and its required BIOS. Family support does not confirm the firmware installed on a retail board.
MSI A520M-A PRO — manufacturer specificationsManufacturer specification · Check MSI's exact CPU support list and its required BIOS. Family support does not confirm the firmware installed on a retail board.
MSI B450M-A PRO MAX II — manufacturer specificationsMSI B450M-A PRO MAX II — exact model datasheetThese descriptions or measurements differ. Wording alone does not establish a different capability; check the exact configuration.
MSI's rear-panel list for this board does not mention a Flash BIOS button; check the manual if you need BIOS flashback. · Manufacturer specification
MSI A520M-A PRO — manufacturer specificationsMSI's rear-panel list for this board does not mention a Flash BIOS button; check the manual if you need BIOS flashback. · Manufacturer specification
MSI B450M-A PRO MAX II — manufacturer specificationsEvidence is missing or conflicting on at least one side. This is not a verified difference.
Manufacturer specification · MSI's datasheet lists EZ Debug LED without the LED count; it is not a numeric POST code display.
MSI A520M-A PRO — exact model datasheetNo source recorded for this side.
Evidence is missing or conflicting on at least one side. This is not a verified difference.
MSI lists RAID modes for SATA drives only; NVMe RAID support is not stated. · Manufacturer specification
MSI A520M-A PRO — manufacturer specificationsMSI lists RAID modes for SATA drives only; NVMe RAID support is not stated. · Manufacturer specification
MSI B450M-A PRO MAX II — manufacturer specificationsEvidence is missing or conflicting on at least one side. This is not a verified difference.
9 shared fields have the same recorded value.
| Specification | MSI A520M-A PRO | MSI B450M-A PRO MAX II |
|---|---|---|
CPU socket SourcesMSI A520M-A PRO Manufacturer specification · Match the exact CPU and required BIOS as well as the physical socket. MSI A520M-A PRO — manufacturer specificationsMSI B450M-A PRO MAX II Manufacturer specification · Match the exact CPU and required BIOS as well as the physical socket. MSI B450M-A PRO MAX II — manufacturer specifications | AM4 | AM4 |
ChipsetDifferent SourcesMSI B450M-A PRO MAX II Manufacturer specification MSI B450M-A PRO MAX II — manufacturer specifications | AMD A520 | AMD B450 |
Form factor SourcesMSI A520M-A PRO Manufacturer specification · Board dimensions, not retail packaging. Check case mounting positions, clearance and cable routing. MSI A520M-A PRO — manufacturer specificationsMSI B450M-A PRO MAX II Manufacturer specification · Board dimensions, not retail packaging. Check case mounting positions, clearance and cable routing. MSI B450M-A PRO MAX II — manufacturer specifications | Micro-ATX; 236 × 200 mm | Micro-ATX; 236 × 200 mm |
CPU support / BIOS sourceDifferent SourcesMSI A520M-A PRO Manufacturer specification · Check MSI's exact CPU support list and its required BIOS. Family support does not confirm the firmware installed on a retail board. MSI A520M-A PRO — manufacturer specificationsMSI B450M-A PRO MAX II Manufacturer specification · Check MSI's exact CPU support list and its required BIOS. Family support does not confirm the firmware installed on a retail board. MSI B450M-A PRO MAX II — manufacturer specificationsMSI B450M-A PRO MAX II — exact model datasheet | AMD Ryzen 5000 / 5000 G-Series / 4000 G-Series / 3000 / 3000 G-Series | AMD Ryzen 5000 / 5000 G-Series / 4000 G-Series / 3000 / 3000 G-Series / 2000 / 2000 G-Series / 1000 Series and Athlon with Radeon Vega Graphics |
Memory type, slots and limitDifferent SourcesMSI A520M-A PRO The overclocked speed is MSI's 1DPC 1R maximum; MSI lists 1DPC 2R up to 3866 MHz. JEDEC speeds run up to DDR4-3200. · Manufacturer specification · CPU, BIOS and validated DIMM population determine supported capacity and speeds. DDR4 and DDR5 are not interchangeable. MSI A520M-A PRO — manufacturer specificationsMSI B450M-A PRO MAX II Manufacturer specification · CPU, BIOS and validated DIMM population determine supported capacity and speeds. DDR4 and DDR5 are not interchangeable. MSI B450M-A PRO MAX II — manufacturer specifications | 2 DDR4 DIMM slots; dual channel; up to 64 GB; up to DDR4-4600+ (OC); A-XMP; non-ECC unbuffered | 2 DDR4 DIMM slots; dual channel; up to 64 GB; up to DDR4-4133 (OC); A-XMP; non-ECC unbuffered |
Maximum listed memory SourcesMSI A520M-A PRO Manufacturer specification · Manufacturer capacity ceiling for this exact board, not included memory or a performance measurement. CPU, BIOS, DIMM population and the validated-module list determine support. DDR4 slots require DDR4 modules; DDR4 and DDR5 are not interchangeable. MSI A520M-A PRO — manufacturer specificationsMSI B450M-A PRO MAX II Manufacturer specification · Manufacturer capacity ceiling for this exact board, not included memory or a performance measurement. CPU, BIOS, DIMM population and the validated-module list determine support. DDR4 slots require DDR4 modules; DDR4 and DDR5 are not interchangeable. MSI B450M-A PRO MAX II — manufacturer specifications | 64 GB | 64 GB |
DIMM slots SourcesMSI A520M-A PRO Manufacturer specification · Physical DDR4 module positions, not included modules. Consult the board manual for population order and compatible capacities. MSI A520M-A PRO — manufacturer specificationsMSI B450M-A PRO MAX II Manufacturer specification · Physical DDR4 module positions, not included modules. Consult the board manual for population order and compatible capacities. MSI B450M-A PRO MAX II — manufacturer specifications | 2 | 2 |
Memory population OC limitsDifferent SourcesMSI A520M-A PRO MSI labels these memory speeds in MHz (manufacturer notation); they are the rated data rates. · Manufacturer specification · Manufacturer A-XMP/OC limits, not guaranteed stability or measured performance. CPU, BIOS and memory-module compatibility apply. MSI A520M-A PRO — manufacturer specificationsMSI B450M-A PRO MAX II Manufacturer specification · Manufacturer OC configurations, not guaranteed kit speed or measured application performance. CPU, BIOS, memory rank and DIMMs per channel determine support. MSI B450M-A PRO MAX II — manufacturer specifications | 1DPC 1R: 4600 MHz; 1DPC 2R: 3866 MHz | A-XMP OC settings listed through DDR4-4133 |
ECC memory operating modeDifferent SourcesMSI A520M-A PRO Manufacturer specification · ECC modules run in non-ECC mode, so error correction is not active. MSI A520M-A PRO — manufacturer specificationsMSI B450M-A PRO MAX II Manufacturer specification · ECC modules run in non-ECC mode, so error correction is not active. MSI B450M-A PRO MAX II — manufacturer specifications | ECC UDIMM accepted in non-ECC mode | ECC UDIMM supported in non-ECC mode |
Storage interfacesDifferent SourcesMSI A520M-A PRO The M.2 slot connects to the CPU. · Manufacturer specification · With Athlon processors with Radeon Vega Graphics the M.2 slot works in SATA mode only. It accepts 2242/2260/2280 drives. MSI A520M-A PRO — manufacturer specificationsMSI B450M-A PRO MAX II M2_1 connects to the CPU. · Manufacturer specification · M2_1 accepts 2280/2260/2242 drives. MSI B450M-A PRO MAX II — manufacturer specifications | 1 × M.2 PCIe 3.0 x4; M.2 slot also supports SATA; 4 × SATA 6 Gb/s | 1 × M.2 PCIe 3.0 x4; M2_1 also supports SATA; 4 × SATA 6 Gb/s |
Onboard M.2 storage slots SourcesMSI A520M-A PRO Manufacturer specification · Onboard M.2 storage positions only. With Athlon processors with Radeon Vega Graphics, MSI lists SATA mode only for M.2. Supported M.2 lengths are 2242/2260/2280; verify the exact processor support list. MSI A520M-A PRO — manufacturer specificationsMSI B450M-A PRO MAX II Manufacturer specification · Onboard M.2 storage positions only. Verify drive type and CPU support for the M.2 slot. No additional storage slot is inferred from a PCIe expansion connector. MSI B450M-A PRO MAX II — manufacturer specifications | 1 | 1 |
SATA storage ports SourcesMSI A520M-A PRO Manufacturer specification · SATA 6 Gb/s connectors, not supplied drives or power cables. With Athlon processors with Radeon Vega Graphics, MSI lists SATA mode only for M.2. Supported M.2 lengths are 2242/2260/2280; verify the exact processor support list. MSI A520M-A PRO — manufacturer specificationsMSI B450M-A PRO MAX II Manufacturer specification · SATA 6 Gb/s connectors, not supplied drives or power cables. Verify drive type and CPU support for the M.2 slot. No additional storage slot is inferred from a PCIe expansion connector. MSI B450M-A PRO MAX II — manufacturer specifications | 4 | 4 |
SATA RAID modes SourcesMSI B450M-A PRO MAX II Manufacturer specification · Requires compatible drives and array configuration; no data protection guarantee. MSI B450M-A PRO MAX II — manufacturer specifications | RAID 0/1/10 | RAID 0/1/10 |
Primary PCIe linkDifferent SourcesMSI A520M-A PRO Manufacturer specification · x16 with Ryzen 5000/5000G/4000G/3000; x8 with Ryzen 3000G; x4 with Athlon with Radeon Graphics processors. Check the CPU support list for the exact processor. MSI A520M-A PRO — manufacturer specificationsMSI B450M-A PRO MAX II Manufacturer specification · Not a measured graphics performance result. MSI B450M-A PRO MAX II — manufacturer specifications | x16 slot: CPU PCIe 3.0 up to x16 | PCI_E1: CPU PCIe 3.0 up to x16 |
Secondary expansion linksDifferent SourcesMSI B450M-A PRO MAX II Manufacturer specification · Electrical links and physical connectors are separate; no measured performance is inferred. MSI B450M-A PRO MAX II — manufacturer specifications | 1 PCIe 3.0 x1 slot | 1 PCIe 2.0 x1 slot |
Onboard audio hardwareDifferent SourcesMSI A520M-A PRO Manufacturer specification · Manufacturer-listed onboard audio hardware, not a measured sound-quality result. Where alternatives are listed, no particular unseen controller revision is promised. MSI A520M-A PRO — manufacturer specificationsMSI B450M-A PRO MAX II Manufacturer specification · Manufacturer-listed onboard audio hardware, not a measured sound-quality result. Where alternatives are listed, no particular unseen controller revision is promised. MSI B450M-A PRO MAX II — manufacturer specifications | Realtek ALC892 or ALC897 codec; 7.1-channel | Realtek ALC897 codec; 7.1-channel |
Processor-dependent display outputsDifferent SourcesMSI A520M-A PRO Manufacturer specification · Requires a processor with integrated graphics; supported modes depend on the CPU. MSI A520M-A PRO — manufacturer specificationsMSI B450M-A PRO MAX II Manufacturer specification · Requires integrated CPU graphics; supported modes depend on processor. MSI B450M-A PRO MAX II — manufacturer specifications | HDMI 2.1: up to 4096×2160 at 60 Hz; DVI-D: up to 1920×1200 at 60 Hz | HDMI 2.0b: up to 4K 60 Hz; DVI-D: 1920×1200 at 60 Hz |
Rear USB ports SourcesMSI A520M-A PRO Manufacturer specification · The detailed specification identifies the two rear USB 2.0 ports as Type-A. MSI A520M-A PRO — manufacturer specificationsMSI B450M-A PRO MAX II Manufacturer specification · Port inventory and interface ratings, not simultaneous measured throughput or charging power. MSI B450M-A PRO MAX II — manufacturer specifications | 2 USB 2.0; 4 USB 5 Gb/s Type-A | 2 USB 2.0; 4 USB 5 Gb/s Type-A |
Front USB header capacityDifferent SourcesMSI A520M-A PRO Manufacturer specification · Internal-header capacity; requires compatible case ports and wiring. Not rear-panel sockets. MSI A520M-A PRO — manufacturer specificationsMSI B450M-A PRO MAX II Manufacturer specification · Requires compatible case ports and cabling; not rear sockets. MSI B450M-A PRO MAX II — manufacturer specifications | 4 USB 2.0; 2 USB 5 Gb/s | 4 USB 2.0; 2 USB 5 Gb/s Type-A |
Network interfacesDifferent SourcesMSI A520M-A PRO Manufacturer specification · Wired Ethernet only; MSI lists no Wi-Fi or Bluetooth hardware for this board. MSI A520M-A PRO — manufacturer specificationsMSI B450M-A PRO MAX II MSI's specification page lists a Realtek 8125 2.5 Gbps LAN controller and a 2.5G LAN rear port, and the model datasheet names the Realtek 8125BG. An older section of MSI's page that listed a Realtek 8111H Gigabit controller conflicts with both and no longer appears on the page. · Manufacturer specification · Wired Ethernet only; no Wi-Fi or Bluetooth module is listed for this board. MSI B450M-A PRO MAX II — manufacturer specificationsMSI B450M-A PRO MAX II — exact model datasheet | Realtek 8111H 1 Gb Ethernet | Realtek 8125BG 2.5 Gb Ethernet |
Fan and pump headers SourcesMSI A520M-A PRO Manufacturer specification · Counts do not establish connector current limits. MSI A520M-A PRO — manufacturer specificationsMSI B450M-A PRO MAX II Manufacturer specification · Board headers, not supplied fans or an assertion of current limits. MSI B450M-A PRO MAX II — manufacturer specifications | 1 CPU; 1 system fan header | 1 CPU; 1 system fan header |
Diagnostic indicators SourcesMSI A520M-A PRO Manufacturer specification · MSI's datasheet lists EZ Debug LED without the LED count; it is not a numeric POST code display. MSI A520M-A PRO — exact model datasheetMSI B450M-A PRO MAX II No source recorded. | EZ Debug LED | Not provided |
NVMe RAID modes SourcesMSI A520M-A PRO MSI lists RAID modes for SATA drives only; NVMe RAID support is not stated. · Manufacturer specification MSI A520M-A PRO — manufacturer specificationsMSI B450M-A PRO MAX II MSI lists RAID modes for SATA drives only; NVMe RAID support is not stated. · Manufacturer specification MSI B450M-A PRO MAX II — manufacturer specifications | Not provided | Not listed by the manufacturer |
|---|---|---|
Rear Flash BIOS button SourcesMSI A520M-A PRO MSI's rear-panel list for this board does not mention a Flash BIOS button; check the manual if you need BIOS flashback. · Manufacturer specification MSI A520M-A PRO — manufacturer specificationsMSI B450M-A PRO MAX II MSI's rear-panel list for this board does not mention a Flash BIOS button; check the manual if you need BIOS flashback. · Manufacturer specification MSI B450M-A PRO MAX II — manufacturer specifications | Not provided | Not listed by the manufacturer |
Closest motherboards to this pair by shared key specifications. Not a popularity ranking.
Each record represents an explicitly checked model and configuration. Original import: 5 Sept 2026; this is not its verification date. This is not a list of current offers or a popularity ranking.
