Does your motherboard state PCIe M.2 support with your lowest end Athlon processor? Most do not, or limit them to SATA mode only. Look at your motherboard specification page under Storage, you will see something like this
Ok so if I see read this correct:
In order for pci 3.0 x4 to work, I would need a 2nd or 1st gen ryzen etc.
And in that setup I can still have other sata storage or no?
It is not as simple as that.
At least, it is on my Gigabyte A320M-H motherboard.
The manual states:
"Supports only M.2 SATA SSDs when using an AMD 7th Generation A-series or Athlon™ processor."
That said, The M.2 NVMe SSD works fine if this board is equiped with an Athlon 200GE or a Ryzen 3 3200G.
The first one is an Athlon, the second a last generation Ryzen and both are "G".
The ONLY processor which leaves the NVMe SSD unrecognized is the Athlon 3000G.
Where is the logic?
My MoBo is an Asrock A320M-HDV R4.0 and the specs says the following:
1 x Ultra M.2 Socket, supports M Key type 2242/2260/2280 M.2 SATA3 6.0 Gb/s module and M.2 PCI Express module up to Gen3 x4 (32 Gb/s) (with Matisse, Picasso, Summit Ridge, Raven Ridge and Pinnacle Ridge) or Gen3 x2 (16 Gb/s) (with A-Series APU and Athlon 2xxGE series APU)*
So now you need to be smart to find out which applies here. 3000G is told to be in the Picasso family, but it is also close to Athlon 2xxGE series. So I connected a PCIE3x2 module that suitable to both.
I bought a NGFF M.2 NVMe to PCIe 4x adaptor board and put that with the NVMe SSD in the PCIe x16 slot which anyhow doesn't make much sense when you are using an APU.
In this setup, the Athlon 3000G adresses the NVMe in PCIe 3.0 x4 mode and the SSD reaches full speed (even up to 6000 Mb/s in sequential read when the Momentum Cache is activated, see attached images).
And this setup also works with an old 7th generation Athlon A6-9500. In fact, it works with all AMD processors.
Conclusion: The problem of the Athlon 3000G not recognizing any NVMe when directly attached to the M.2 slot on the motherboard really seems to be specific to this processor or, perhaps better expressed, the way this processor is discovered by the various brands of motherboards through the AGESA code.
I asked Gigabyte for a BIOS update but it might be more a job for AMD to come up with some corrected AGESA code.
Interesting to notice, independently of what processor you have or what setup (NVMe on motherboard or add-in card), when the Momentum Cache is activated, the NVMe not only is MUCH faster, but also stays much cooler!
Below, same setup with Momentum Cache deactivated.
The low cost Athlon processors are more aimed at the low end of the market. They support SATA SSD products and they are available at low cost.
My R5 2400G is able to support PCIe SSD products which gives it a leg up on the earlier processors. It also supports a discrete card if it is installed.
My newer R5 3600 is more focused on a discrete video card with more cores and L3 cache etc.
The Athlon 3000 like the 200GE etc are designed as an entry level APU. You get what you pay for using a $50 processor.
This is not what the discussion is about.
The discussion is about the strange fact that the Athlon 200GE DOES support NGFF SSDs and the Athlon 3000G, its successor, DOESN'T.