[Help] Backup speed with TFM on TOS 7.x varies drastically between shares

[tnaspain]

Using TFM Backup v.1.0.155 with latest TOS v7.x on a new T12-500 Pro.

Problem #1: I have a number of shares (shared folders) that I want to back up via TFM Backup.
Most of them back up at about 100-250 MB/second, or internal gigabit speed inside the NAS.
Why so slow? I would expect, because this is interal to the NAS, it should be doing this 5-10x that speed, since the NAS is capable of 10G speed or 1250MB/second). So internally it can handle that rate, or even higher transfer rate since it is only moving data internally and not over some LAN.

Problem #2: I have one large shared folder with about 300,000 files. The largest amount of files on the server. But not the largest space use.
While the other folders copy via TFM Backup at about 100-250 MB/s, this folder want to copy at 0-5 bytes/s, saying that the task will complete in about 35 years.

When it really ramps up and is working "fast", it goes up to 1KB/s. So only a few years at this speed to copy the files

This happens whether or not there are any other shared folders being backed up at the same time, or if it is the only one. (So that is NOT a bottleneck). I have also deleted the task, and then made a new task for the same folder. No change in speed. Something is very corrupted.

Anyone please know what could be throttling or interfering with the backup speed on this one shared folder?

[CursaYang]

Based on the current symptoms, the extremely slow backup speed may be related to the approximately 300,000 files in this shared folder, which could cause TFM Backup to spend significant time scanning files and processing metadata; we recommend performing a local file copy test first to help confirm the cause.
Perform copying using the cp command in the terminal, or conduct a backup test using rsync.