Hello Sanryu85,   Thank you for your reply. I've checked logs from both servers and found follow: There are no hardware issues on servers, All firmware are the latest.   I see that in Backplane 1 of PCIe Extender in Slot 1 are installed 3 PCIe SSD (slot 21,22,23) Part Information Vendor        Toshiba Model        Dell Express Flash CD5 3.84T SFF   According to the Dell EMC PowerEdge RAID Controller S140 User’s Guide, S140 support only follows NVMe PCIe SSDs:   [URL]   I could suppose this could be a reason of not enough disk performance.   Do these drives come from original server configuration?   Additionally, PERC S140 supports only these OS: Microsoft Windows Server 2022 Windows Server 2019 Windows Server 2016   Linux Red Hat Enterprise Linux 7.3 and above SUSE Linux Enterprise Server version 12 SP2 and above   [URL]   Thanks
Hello,we started testing with an R740xd we use the Perc S140 pci extender card connected directly to the backplain. We installed the operating system both by doing a raid 1 and without a raid but the performance they are always similar to these. [root[NAME] sanryu]# /usr/sbin/hdparm -Tt --direct /dev/nvme0n1 /dev/nvme0n1:Timing O_DIRECT cached reads: 2728 MB in 2.00 seconds = 1363.92 MB/secTiming O_DIRECT disk reads: 4492 MB in 3.00 seconds = 1497.06 MB/sec I also tried on several operating systems (debian 11, Centos), and also with another R740xd, with this hardware configuration with the only difference of the cpu (gold and not silver), but the result does not change. I expect at least 3000mb/s but we can't get through 1500 mb/s I have tried 2000 configurations from the bios and on the pci slots on the physical level.The only thing that comes to my mind is the pci extender model, according to you there is an important difference between this pci extender and the DELL 1ygfw modelWe do not understand what we are missing. could you help us understand?   hw info: Toshiba Corporation 3.84 TB Dell Express Flash CD5 3.84T SFF   Disk.Bay.21:Enclosure.Internal.0-1:PCIeExtender.Slot.1
R740xd e dischi nvme perc S140 low performance disk