According to a report by HardwareLuxx, one of its forum members managed to dig information surrounding seven newly unreleased B650 and B650E motherboards from Asus. These boards range from a single Prime model to several TUF Gaming variants and two ROG Strix models. All the motherboards support PCIe 5.0, with one supporting up to four M.2 SSDs.
These boards will include the Prime B650-Plus, TUF Gaming B650M-Plus, TUF Gaming B650M-Plus WiFi, TUF Gaming B650-Plus, TUF Gaming B650-Plus WiFi, ROG Strix B650-A Gaming WiFi, and ROG Strix B650E-E Gaming WiFi. The two TUF SKUs featuring the "B650M" nomenclature are Micro ATX motherboards, while the rest are standard ATX.
It's worth noting this data is not official, so take it with a grain of salt. Any of these specifications or model name numbers are subject to change until Asus officially announce them.
B650 is AMD's new mid-range chipset option for its first generation of AM5 motherboards. The chipset has been downgraded from X670 to supporting PCI-E 5.0 on a single M.2 slot, while B650E will support PCIe 5.0 on the primary PCIe x16 slot and one M.2 slot - at a minimum.
AMD says the performance between the B650 series of chipsets and the X670 series will be the same, so the only differences are related to PCIe connectivity and potentially I/O connectivity as well -- depending on the motherboard manufacturers.
According to the source of the motherboard model data, the Prime B650-Plus and twin TUF gaming B650M motherboards will feature the least amount of storage connectivity, limited to just two M.2 slots, with one of those being Gen 5 supported.
The ATX variants of the TUF Gaming boards, plus the ROG Strix B650-A crank this up a notch by adding a third M.2 slot for a total of two PCIe 4.0 M.2 slots and a single Gen 5 slot.
However, the ROG Strix B650E-E sees the most drastic upgrades - due to the chipset change to B650E. Apparently, Asus has wired this board to feature not only a single PCIe Gen 5 x16 slot but two x16 slots wired for Gen 5. Plus, M.2 storage has been upgraded to four slots in total, with three of those being Gen 4 compatible and one being Gen 5 compatible.
This is all that we know about these new motherboards right now; we'll know more soon once B650 and B650E motherboards start shipping later this year.
I wonder how expensive these will be though... Ugh...
From what I've seen every B series board has 1 PCIe 5.0 M.2 slot no matter the PCIe x16 configuration. I'd imagine it's a lot cheaper to wire that than a full length slot.
I don't see any point in anything above PCIe 3.0 for NAND SSDs on consumer platforms as they stand though. They all have absolutely dismal random performance and nothing can actually take advantage of the read/write performance. Optane is dead (P5800X will likely be the best SSD for years to come sadly) and Kioxia's XL-Flash is non existent on the market (though the first tests I saw had it pretty close to Optane). Hopefully DirectStorage will change things on the consumer side to at least take advantage, but only time will tell.
Honestly I would rather have PCIe 5.0 x16 for the GPU and M.2 storage can all be PCIe 4.0. As a gamer SSD PCIe connectivity has yet to hold me back.
No graphics card is even close to saturating a gen4 bus. I have to agree with Fran, the faster data transfer speeds are better, than the nothing you will see GPU side, unless AMD pulls out a gpu with an x4 gen5 slot. They seem to have a habit of such weirdness, as of late.
Also, as mentioned above, considering that some Ada cards are rumored to be x8 PCIe 5.0, this is much better than the other way round since going 5.0 for the M.2 and 4.0 for the GPU would then lead to the same situation we currently have with the RX6500XT and 6400, just worse because it would affect higher-end cards as well. I seriously doubt AMD and their partner would want that backlash...
For the higher end of the spectrum (GPUs, that is), it's a non-issue though. PCIe4 vs PCIe5 for a full X16 slot, I'll venture a guess and say it's a marginal difference and, more than likely, imperceptible. So a lower end board with a higher end GPU should be a non issue for a PCIe4 X16 slot.
That's all fine if you buy whole PC and stay with it. But if you buy new GPU in 2 years, hm, maybe that x16 4.0 starts hampering your GPU. Or if you go with split x8 for slot and M.2 (well 8+4) maybe your future GPU is full x16 5.0 and again gets a perf hit. I always look at MBO as the most important component, everything else is easily upgradeable. So yeah, call me delusional ;D but when I think about new system I want at least one full x16 5.0 slot and at least one M .2 x4 5.0. That's possible with B650"E", certainly with X670E but probably an overkill for me, and so far impossible with Intel. Now, if those B650E boards start at 300$ they'll get "hell-NO!" from me. If they manage a rough 150-200$ range, I'm there. Don't need WiFi, 2.5GbE, RGB bling, or 4 M.2 slots. So hopefully after initial avalanche of premium boards we get somewhat more sensible models.