Because, wouldn't that still be the case when a 3900X is paired up with a supported B450 mobo too? Hmm. Or maybe 4 and 2.Įdit: The more I think about it, I think my theory about the half write bandwidth is wrong. There are six chipset SATA and two SoC SATA, I think. Is the author un-aware that not all SATA ports are provided by the chipset, on some boards, they fan-out the SoC SATA ports too, as some of the onboard SATA ports? My B450-F ROG STRIX does that, I believe. Couldn't be a hit-piece, could it? Nah.Įdit: I also find it really curious, how he didn't check the SoC SATA ports for some reason. This can of course be tested, if someone has a 3600 and a 3900X CPU, and an X570 board or two.Įdit: I noticed that no-where in that Reddit "article", does the author state WHICH AMD CPU he was using, even though he mentions owning "several". I'm not saying that this IS the reason for the "AMD X570 chipset SATA performance anomaly", but only that it COULD be just a side-effect of having half the write bandwidth with a lesser CPU. (Edit: I do believe that chipset memory writes, since the memory-controller is on the CPU, are affected by this issue likewise.) And again, still, it has the limitation that it is shared over DMI bus, which means that a heavily-loaded system with an NVMe SSD is going to perform worse, compared to AMD, even with AMD's supposedly-inferior chipset SATA ports, simply because AMD's AM4 platform has dedicated x4 PCI-E lanes for the primary NVMe slot.Ĭlick to expand.Because AHCI ports DMA data to / from main memory, AFAIK. It has only been with Skylake and newer Intel chipset / platforms, that their SATA performance, across all ports, was basically top-notch. thinking of boards with Intel SATA6G ports and SATAII ports on the same board, additional chipset Marvell or ASMedia ports, etc. (*) Having SATA ports on a board, with varying SATA performance profiles / capabilities, is nothing new for Intel owners, they've had to deal with it for years. (Didn't Intel "invent" AHCI?) I would personally find that explanation "enough".īut they really need to test the SoC SATA ports too, on both B450 and X570 boards, and compare all around. Just that the Intel ones has been known for some time, whereas, the AMD SATA limitation may be kind of out of the blue here.īut knowing AMD's "history", with implementing their own AHCI ports, I wonder if it's simply that, an AMD implementation that was in some way lacking compared to Intel. They're both chipset limitations (if the AMD chipset SATA issue is true, which I suspect that it probably is). I would rather have full-speed dual NVMe 4.0 slots, and slightly-gimped SATA ports, than full-speed SATA ports, and really gimped NVMe slots.Ĭlick to expand.Not really. Who uses SATA for anything but large spinners these days anyways, with most higher-end X570 boards having TWO PCI-E 4.0 x4 NVMe slots for primary storage. IMHO, the NVMe "slowdown" on Intel platforms, is a WORSE issue, than AMD's SATA performance. (And network and sound onboard PCI-E x1 devices, as well.) Thus, Intel consumer platforms have to share the DMI bandwidth (roughly PCI-E 3.0 x4 itself) between the chipset-attached NVMe slot, and the REST of the I/O, including SATA ports, and chipset PCI-E x1 slots. Seems possible that this is a real issue, but where are the big headlines about Intel's consumer chipsets and PCI-E 3.0 x4 NVMe slowdown, due to the fact that Intel platforms DON'T have a dedicated PCI-E 3.0/4.0 x4 lane bundle for the NVMe slot, like AMD's AM4 platform does. Traditionally, AMD's own chipsets, have had worse AHCI performance than Intel, although ASMedia SATA port add-on cards were often worse still. If true, that COULD potentially point to a BIOS bug, or other bug, somewhere. One thing though - have they compared the 4K random scores, between the SoC (on-CPU-die) SATA ports, and the "Chipset" SATA ports, between the B450 and X570? That might be interesting, to see if the SoC SATA ports actually have different performance, between B450 and X570, using the SAME CPU (model).
AMD themselves developed (supposedly?) the X570 chipset.
If you think about it, really, it's not all THAT surprising.
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