TerraMaster Forum

Hi there,

I have an issue with D8 Hybrid in that whatever drive I put into Bay 4 has VERY slow write speeds (read seems okay) and eventually the disk unmounts itself. If I switch disk sbetween bays they function as expected, but whatever disk is in Bay 4 exhibits this behaviour.

Anyone seen anything similar?

We sincerely apologize for any inconvenience you may have experienced. May we inquire whether the issue with the D8 Hybrid product occurred immediately upon purchase or after a period of use? If the read speed is performing normally, the write speed should generally be stable as well. Could you please confirm that the content of the files involved is consistent during both read and write operations?

Yes, I believe it has been from the start. I originally thought it was just the disk so stopped using bay 4, without really investigating the issue. FYI, I bought the D8 in Dec 2024 and I am on MacOS 15.1.1 (24B91)

Files are constant and have also used BlackMagic disk speed test.

@TMjack - so what are the next steps for getting a fix for this?

I am having Bay 4 issues as well. Whenever I try to write to the drive in Bay 4 the drive disconnects.

I’ve tried different drives, computers, cables all the same thing. I have to restart the computer and the D8.

This has been happening since I purchased the D8.

Any idea on a way to fix?

Uridith wrote: ↑08 Feb 2025, 16:52

The total bandwidth of the D8 Hybrid is 10 Gb/s, and each TDAS controller will display a connection speed of 10 Gb/s in macOS. However, actual performance may vary due to various factors.

If you are using macOS, please go to "About This Mac" > "System Report" > "USB" to check if the TDAS controller's connection bandwidth is displayed as 10 Gb/s. If it shows 5 Gb/s, the speed cannot be achieved, and we recommend checking if there are any issues with the connection.

To determine if the speed issue is caused by disk performance, we recommend testing a single hard drive. A HDD can theoretically reach up to approximately 256 MB/s.
If you use four HDDs, the speed will be divided equally across the 10 Gb/s bandwidth, for example, 1000 / 4 ≈ 250x1.

davrizio wrote: ↑17 Feb 2025, 12:12

If you are using a Windows PC, we recommend visiting the official brand website to download and install the latest chipset drivers for your machine. Updating drivers may resolve compatibility-related issues.
If the disconnection occurs after waking from sleep mode, we suggest disabling custom sleep settings. For more details, please refer to the following link: viewtopic.php?t=3840

Thanks for your reply!

I am on MacOS and have checked the system info and it is using the full 10gb connection.

I have access to a Windows computer and updated the chipset firmware to the latest version several weeks ago.

I also made sure the drives do not go to sleep.

It is only Bay 4 that is having issues. For me the other 3 bays and 2 nvme drives work fine!

davrizio wrote: ↑17 Feb 2025, 22:22

Please contact service(at)terra-master.com with a video illustrating the failure.

Thank you! I sent an email with videos to service(at)terra-master.com.