Knowledge

tkaiser has some additional information from his initial testing at https://github.com/ThomasKaiser/Knowledge/blob/master/articl... if people are curious to know more, though it should be noted these were early release samples and as such, software/firmware isn't exactly perfect at the moment

One thing worth noting is that basically, even now (almost 10 months post announcement), almost no one has a 6000U laptop outs (a search on Amazon and Best Buy shows two 6800U laptop models total, one Asus and one Lenovo). Two niche vendors, XMG and Star Labs, have both publicly stated that they would have loved to have offered Ryzen 6000 laptops, but couldn't get any allotments. There are were also well documented chipset issues - even into the summer Lenovo and Asus talked about requiring firmware updates to enable their USB4 ports. That being said, starting w/ Rembrandt, AMD now has full 40Gbps USB4 controllers built on-chip. I'm really looking forward to Ryzen 7040 because Phoenix looks great (Zen4 + RDNA3 on TSMC N4 - yes please) and hopefully USB4 support has matured enough on the AMD side that Framework is able to release something

A2 needs support in the Linux kernel. It's not there, yet. https://github.com/ThomasKaiser/Knowledge/blob/master/articl... "A2 promises even better performance with 4000/2000 read/write IOPS minimum but there's a problem since as outlined by the SD Association A2 cards show "much higher performance than A1 performance by using functions of Command Queuing and Cache". Cache and Command Queuing require host (driver) support since the host needs to activate those new features first. The cache feature on A2 rated cards makes use of volatile RAM on the card requiring the host to learn new commands to issue flushing the cache (involving the risk of data losses -- for details see especially chapter 4.17 in Physical Layer Simplified Specification 6.0)"

My understanding is that A2 cards are generally slower than A1 cards IF you don't have host-side support for managing the volatile-RAM caching that A2 requires. So if the Pi 4 only allows you to run in A1 mode anyway, you're better off buying the A1 card and both saving money and getting a faster card. I don't know if that lack of support is true of the Pi 4, but it does seem to be true of most other SBCs according to https://github.com/ThomasKaiser/Knowledge/blob/master/articl...

IIRC, SATA over USB3 can offer competitive performance for sequential I/O, but PCIe will give better random I/O performance and lower CPU usage. tkaiser of the armbian project has a lot to say about this stuff. I find his posts in the cnx-software.com comments and armbian forums very helpful. https://forum.armbian.com/topic/8097-nanopi-m4-performance-a... https://github.com/ThomasKaiser/Knowledge