There is no way to answer that because "B650" is not a motherboard model. It's a chipset family. And the question was asked, and answered by the manufacturer on the Best Buy page you linked to that WHICH B650 motherboard it comes with depends entirely on what they are able to obtain at the time they are building so the exact same prebuilt purchased one week might have an entirely different motherboard than the exact same one purchased a week, or a month later. But in general there is nothing wrong with motherboards that use the B650 chipset.
The B650 chipset is the "middle" ground when it comes to the motherboard chipset families for this generation of Ryzen, with the X670 and X670e boards being the premium series. B650 based boards are totally fine, but what matters, and what you are very unlikely to be able to find out from iBuypower (Also known as "iBuildCrap" to a lot of people) is exactly which board it would come with. You'd most likely have to literally buy the unit and take it out of the box and then look to see what board it came with in order to know. It's possible that if you buy it in person the store MIGHT allow it to be opened to see what board it was built with but I very much doubt it. And in general, iBuypower and Cyberpower PC both use the cheapest boards from whatever chipset family they are using for a given model, that they can get in bulk.
That isn't always a deal breaker, per se, but if you are going to spend the money on a build that uses a Ryzen 9 I would suggest that it is a VERY good idea that you KNOW it comes with at least a mid range board from the chipset family it uses or else it's very likely you will have issues due to the use of low quality VRMs or a lack of heatsinks on the VRMs. And just in general.
An 800w PSU should be plenty of capacity for an RTX 4070 ti, because the recommendation is a good 650-750w unit, but given the tendency for the 4000 series to have somewhat high power excursions, also known as power or transient spikes, it's a good idea to have a unit that can supply a moderately greater capacity for brief periods of time to handle such spikes. And if we're being honest, there are VERY few "800w" power supplies out there that are any good, at all. In fact, right now, the number of them that I can see is more like, none. Anything with decent or good quality, for the most part, is going to be using a platform that comes in increments more like 550w, 650w, 750w, 850w, 1000w, 1200w, etc. My guess, if I had to guess, is that this probably comes with some flavor of "High power electronic co Ltd." 800w power supply but in reality it could be just about anything because they do the same thing with graphics cards and power supplies that they do with motherboards, which is use whatever they can get in bulk that's cheap, so they can keep their profit margins high.
In any case, I've rarely seen an iBuypower PC system that came with any kind of decent power supply model. I've seen some that came with somewhat "ok" units, but generally they come with something cheap. I'm sure there are exceptions, I just don't know that I've seen any.
In reality though, depending on whether what's included is even acceptably ok quality hardware, the price probably isn't that terrible as it would cost a bit more to do approximately the same build yourself, besides which you'd have to build it. It would however, even using cheaper parts, probably result in a moderately higher quality build. Especially when you factor in things like the (probably) very low quality IPB (Whoever that is) AIO cooler that system comes with. I've never heard of them and they are not listed on PC Part picker, so they are likely an unknown knockoff type brand and when it comes to liquid coolers, I generally suggest avoiding cheap products if you value your hardware.
PCPartPicker Part List
CPU: AMD Ryzen 9 7900X 4.7 GHz 12-Core Processor ($394.80 @ Amazon)
CPU Cooler: ARCTIC Liquid Freezer II 280 72.8 CFM Liquid CPU Cooler ($106.44 @ Amazon)
Motherboard: Gigabyte B650 GAMING X AX ATX AM5 Motherboard ($159.99 @ Amazon)
Memory: G.Skill Flare X5 32 GB (2 x 16 GB) DDR5-6000 CL36 Memory ($95.99 @ Amazon)
Storage: Crucial MX500 1 TB 2.5" Solid State Drive ($48.53 @ Amazon)
Storage: Seagate BarraCuda Q5 1 TB M.2-2280 PCIe 3.0 X4 NVME Solid State Drive ($52.98 @ Amazon)
Video Card: Zotac GAMING Trinity OC GeForce RTX 4070 Ti 12 GB Video Card ($729.99 @ Newegg)
Case: HYTE Y60 ATX Mid Tower Case ($179.99 @ Amazon)
Power Supply: Thermaltake Toughpower GF1 PE 850 W 80+ Gold Certified Fully Modular ATX Power Supply ($99.99 @ Amazon)
Operating System: Microsoft Windows 11 Home Retail - Download 64-bit ($119.99 @ Newegg)
Total: $1988.69
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2023-11-19 18:45 EST-0500
Facebook
Twitter
Instagram