There’s no such thing as too many ports on a desktop computer. ASRock seems to be embracing that philosophy, because its latest motherboard has more than any we’ve ever seen. The z790 LiveMixer (what?) includes 23 USB ports — you can count every one of them in Keith May’s live CES coverage in your latest YouTube video. The board is an attention-grabber even before you see the rear panel, thanks to a purple graffiti-inspired paint job plastered across its various shields and heatsinks. (The AMD B550 version will be orange, by the way.) But take a look at the back, and you’ll see two USB 3.2 Gen…