The ASRock Phantom Gaming B850I Lightning Wi-Fi turned out to be a bit of a rollercoaster. Is it affordable and good value? Yes. It's the cheapest 800-series chipset board we've tested by a long way and still does a good enough job in handling AMD's current flagship desktop processor. As a comparatively cheap way of going Mini-ITX with Socket AM5 it ticks most boxes. The VRMs were cool enough, although we'd definitely check temperatures there in your own system as Mini-ITX cases can vary massively in terms of airflow. Still, it wasn't much warmer here than the ATX boards we've tested with this processor, so unless you're regularly throwing multithreaded workloads at a 16-core CPU, you'll likely be fine.

In terms of aesthetics, you'll be disappointed if you want inbuilt RGB lighting, but it's clear that ASRock was trying to hit as low a price point here as possible, so cuts have to be made to the non-essential features. What's classed as non-essential is subjective, though, so it's worth re-stating what you don't get here. Wi-Fi 7 has been ditched and there's no USB4, coupled with the fact it's not capable of cooling PCIe Gen 5 SSDs, you'd be right in questioning why you're opting for this particular B850 chipset motherboard and not one of its predecessors. Its B650 predecessor, for example, also supports PCIe Gen 5 SSDs and like this board would require a third party heatsink, and has the same Wi-Fi standard and a similar USB port configuration. The key differences are a more capable audio codec—ALC1220 here over ALC892 on the old board, a couple of extra higher amperage vCore power phases and a PCIe x16 slot that's PCIe Gen 5 capable.

The price difference varies, though, and in the US you'll likely only be saving $10-20 at most. If that's the case it's definitely worth getting the B850 option for those enhanced features. Other manufacturers' boards are also worth watching out for as the release of the B850 chipset has seen price cuts for the likes of the MSI MPG B650I Edge Wi-Fi at $190 and GIGABYTE B650I AORUS Ultra at $240. These have more substantial heatsinks and the Gigabyte board even has a trio of M.2 ports and a slightly better USB configuration, but lacks PCIe Gen 5 support on M.2 or x16 slot support, or both.

In short, just because there's B850 on the box, doesn't necessarily mean this board is better than B650 options. In fact in some areas its slightly inferior or at least doesn't offer any chipset-related benefits. For a mid-range system and PCIe Gen 4 SSD, this board would be absolutely fine, so the only real questions are whether you'd benefit from the likes of USB4 or Wi-Fi 7 in the long run. However, even the likes of the ASUS ROG Strix B850-I Gaming Wi-Fi, which costs $100 more, still lacks USB4, so it likely means spending twice as much to get those features. If you're happy with Wi-Fi 6E, 10 Gbps limit on rear USB ports, USB 3.0 on the front panel Type-C port and getting a third party heatsink if you want to use a PCIe Gen 5 SSD, then it's about as good an option as any other Socket AM5 Mini-ITX motherboards for around $200. Only spending significantly more will get you something noticeably better. The relatively spartan PCB also means it should have no compatibility issues with large heatsinks or AIO liquid cooler pumps, which can't be said for some of the double height M.2 heatsinks present on other boards.

There are things we'd change about the board to perhaps lower the price still further, too. The 2-pin thermistor header would be a welcome feature on more expensive boards, especially if your system is watercooled as you could tie in coolant temperature to fans speeds or keep an eye on it if you're using PETG rigid tubing that can deform at relatively low temperatures. The chances of this board encountering a custom watercooling system are probably near zero so honestly, on a budget-focussed board it feels a bit excessive. There's also an argument for ditching one of the 3-pin RGB headers and even the SATA ports given most Mini-ITX users will be using M.2 SSDs these days to save space and cut down on cables. Thankfully, most of ASRock's cuts have been in the right areas. You still get a decent audio codec, the VRMs and heatsinks are capable enough as is the M.2 heatsink, at least for PCIe Gen 4 SSDs, so while it doesn't stand out for reasons other than its low price and ability to deal with 16-core CPUs, if you have around $200 to spend on a Socket AM5 Mini-ITX board, it will do the job fairly well.