Issue: When transferring any size or amount of files to NAS RAID via FTP the transfer rate is abysmally slow at 3MB/s. When I transfer same files across a SMBv1 connection I can achieve 11.3MB/s. Given the below specs, I cannot reconcile 3MB/s transfer speeds as it would take over 2 weeks to finish a tiny 500GB transfer.
Source Desktop: Windows 10 w/ 16GB RAM & Core i7 @ 3.40GHz w/ Intel 82579LM NIC – Rated for 1 Gigabit
Source Drive: WD 5400RPM HDD Connected and Rated for SATAIII 6.0Gb/s
Network: Source/Destination Connected via Cat6 Ethernet to Asus RT-AC1200 Router – Rated for 100MB/s
Destination RAID: Buffalo TS-XLC66 w/ RAID 10 – Rated for 100MB/s (Latest Firmware v1.76 released as of 2.14.2022)
Destination Drives 4x WD 2TB 5400RPM HDDs
I have tried/diagnosed the following with no change:
- FileZilla: Transferring <10MB or 4GB files tops outs at 3MB/s, even.
- CyberDuck: Transferring <10MB or 4GB files tops out at 5.1MB/s.
- SMBv1: Transferring <50MB or 4GB files achieves 11.3MB/s
- Different Router: Asus TM-AC1900 (Rated for 1 Gigabit) – maxes out FTP transfer at 3MB/s
- Different RAID (same HDDs): Buffalo TS-X4.0TL/R5 – maxes out FTP transfer at 3MB/s
- Different Cat 6 Cables (<10ft btw)
- Removed all traffic on network to only FTP/SMB connection between Source and Destination.
- All HDDs in question have ‘Good’ SMART results individually tested via Speccy and CrystalDiskInfo
- Transferring files via FTP to a different destination device (SBC) produces 10MB/s+ speeds.
- Tried to research this particular issue but cannot find exact fit. This question/issue comes close but isn’t the same
- Disabling Windows Firewall
- FTP transfer from command line in both Active and Passive Mode.
- The OS and all drivers and devices have been checked and rechecked for updates.
Given the information and diagnostics above my understanding is that the bottleneck is likely the RAID. However, I also suspect it may be software since different FTP softwares produce different maxes. While I do not expect anything close to 100MB/s, 3MB/s is horrifically low even taking into consideration the CPU of the RAID and 2x reduction of HDD write speed when using RAID 10. Especially if the device proves to be capable of writing at least 11MB/s.
Questions: Why are FTP transfer rates so slow overall? Why are SMBv1 speeds 4x greater than FTP?
