There are two PCI-E 16x slots on ASRock B450M Pro4 motherboard. Which one is PCI-E 16x 3.0 and which one is PCI-E 16x 2.0 slot? - Quora
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Amazon.com: Asrock B450 PRO4 R2.0 AM4 AMD Promontory B450 SATA 6Gbps ATX AMD Motherboard : Electronics
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CMS 16GB (2X8GB) DDR4 19200 2400MHZ NON ECC DIMM Memory Ram Upgrade Compatible with Asrock® A320M Pro4, AB350 Pro4, AB350M Pro4, B250 Pro4, B250M Pro4, B450 Pro4, B450M Pro4 Motherboards - C112 -
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Amazon.com: ASRock B450M PRO4 AM4 AMD Promontory B450 SATA 6Gb/s USB 3.1 HDMI Micro ATX AMD Motherboard : Electronics
![Amazon.com: CMS 16GB (2X8GB) DDR4 19200 2400MHZ Non ECC DIMM Memory Ram Upgrade Compatible with Asrock® A320M Pro4, AB350 Pro4, AB350M Pro4, B250 Pro4, B250M Pro4, B450 Pro4, B450M Pro4 Motherboards - Amazon.com: CMS 16GB (2X8GB) DDR4 19200 2400MHZ Non ECC DIMM Memory Ram Upgrade Compatible with Asrock® A320M Pro4, AB350 Pro4, AB350M Pro4, B250 Pro4, B250M Pro4, B450 Pro4, B450M Pro4 Motherboards -](https://m.media-amazon.com/images/I/61Y-Zq6tepL._AC_UF1000,1000_QL80_.jpg)