The M.2 NVMe SSD may be using an incorrect transfer mode.
The M.2 NVMe SSD may be using an incorrect transfer mode.
Hi! It appears that my second onboard M.2 NVME SSD is running at PCIe Gen 3.0 x1 (or PCIe 2.0 x2) speeds instead of PCIE 3.0 x2 or x4. I determined this based on CrystalDiskMark 8 where my first SSD manages ~2.5GB/s R/W and the second one only manages 0.8GB/s R/W. This actually happens with 2 different PCIe 3.0 x4 SSDs. Any suggestions on what might happen? Background info: Motherboard: Gigabyte Aorus B550 Elite V2 (see attached files) - The first M.2 SSD slot (M2A_CPU) can achieve up to PCIe 4.0 x4 through the CPU (and it does) - The second M.2 SSD slot (M2B_SB) can achieve up to PCIe 3.0 x4 through the chipset (doesn't seem like it does) The only hardware connected to the MB are the Graphics card (RTX2060) and the 2 M.2 NVMEs Link to manual SSDs: - System: Samsung 970 EVO 500GB (PCIe 3.0 x4) - Data: Sabrent Rocket 2TB (PCIe 3.0 x4) - Data: ADATA XPG SX8100 4TB (PCIe 3.0 x4) Crystal Diskinfo reports PCIe 3.0 x4 for all drives, but is that what the drive reports it can do, or what the actual connection is (seems wrong) (Waiting for a PCIe slot adapter to install the third drive permanently, but both "data" drives have the same speed in that second M.2 slot. The speed the third drive will run at in the slot adapter is not the question) CPU: Ryzen 5 5600X (Allows for PCIe 4.0) PCIe speeds: PCIe 3.0 x1 maxes out at ~1GB/s PCIe 3.0 x4 maxes out at ~4GB/s BIOS Settings: The only related settings I could find in the BIOS didn't help (I tried more or less all settings), as they seem to relate to the CPU-bound lanes only. - PCIEX16 Bifurcation: Allows you to determine how the bandwidth of the PCIEX16 slot is divided. Options: Auto, PCIE 2x8, PCIE 1x8/2x4, PCIE 2x4/1x8. - PCIe Slot Configuration: Allows you to set the operation mode of the PCI Express slots to Gen 1, Gen 2, Gen 3, or Gen 4 Any help would be greatly appreciated. Thanks!
The chipset supports four lanes and must accommodate numerous devices.
If the GPU is using 16 lanes, then I think I found your answer. GPU + 3 drives that can use 4 pcie lanes. The 5600x can only do 24 lanes. IIRC your chipset only uses pcie lanes from your CPU. 16+4+4+4 = 28 lanes. Your drive can't use all the lanes it wants
This setup relies on a chipset with a MUX to divide its lanes, enabling multiple slots like M.2, USB, SATA, sound, and PCIe versions. All components share these lanes, so bandwidth is shared but should remain functional. When testing an SSD, performance should stay consistent since other parts won’t be heavily using data. Some boards claim the B550 only supports PCIe 3.0x2 for M.2 drives, whereas X570 uses PCIe 4 and higher lanes via MUXes.
I understand your point. It suggests you wouldn't even be able to utilize the fundamental capabilities of the motherboard. All Ryzen 5000 CPUs, including the R9s, have only 24 lanes, though a dual-channel speed would still work. The 800MB/s bandwidth is sufficient, but if there are configuration issues, it might be better to address them.
The system features 24 PCIe 4.0 lanes. Eight of these are dedicated to connecting with the chipset, supporting up to 8GB/s. This information comes from guru3d. The Ryzen 5000 processors provide a total of 24 PCIe Gen4 connections. Of those, 16 lanes are reserved for graphics cards using x16 or dual x8 configurations. In comparison to PCIe 3.0, a Gen 4.0 x8 link would match the bandwidth of PCIe 3.0 x16. Additional four PCIe lanes from the CPU are allocated for high-speed storage devices like NVMe SSDs. Notably, AMD integrates USB 3.2 Gen2 support directly into the CPU, though this capability is only available with the X570 chipset.
Was das genau gemeint war? Ich habe nicht gesagt, dass es unmöglich ist, die Spuren zu nutzen; ich habe nur gesagt, dass der Antrieb mit anderen Geräten um die Spuren kämpft. Das schränkt seine Fähigkeit ein, sich weiterzubewegen. Klar, wenn ich sagte, dass das Chipset die gleichen Spuren wie deinen CPU teilt, meinte ich, dass es keine eingebauten PCIe-Linien hatte. Keine Ahnung, dass der Chipset einfach jeden Lane, den ein Gerät anfordert, beanspruchte, haha
It was this that confused me: it can take advantage of all available lanes, but it doesn’t guarantee it will receive the bandwidth it needs from those lanes. Since the Transfer Mode appears twice, I think it’s showing both the active mode and the drive’s maximum settings, meaning it is indeed using PCIe 3.0 x4. I’m unsure why it’s running so slowly—I don’t know. Have you attempted copying a big file between the two drives to verify actual performance?