Yes, a faulty power supply can lead to slow disk performance.
Yes, a faulty power supply can lead to slow disk performance.
Reads are slightly lower than writes, which is typical for a SATA hard drive. That’s expected from what I’ve seen. Hard drives tend to slow down over time, with some models performing better than others. When you first used it on USB, the speeds seemed fine. In fact, an old Seagate unit managed around 30-40MB/s for both reading and writing on internal SATA. Eventually, it stopped working. However, problems only appeared after a while. It’s sad when a drive reaches just 10,000 hours. Here’s my external drive—previously achieved 80-100MB/s. It now sits just under 10,000 hours as well. That means it’s been running nonstop for over a year. It never got turned off, which is risky given the low Power On Count. My drive, on the other hand, is around 10 years old and shows fewer power-on hours with a high total. Clearly, it makes sense that read speeds have dropped now.
I wondered if the OP saved a "high-performance power plan" from one of those PC optimizers. It keeps all drives running even when idle, which is okay for SSDs but not ideal for HDDs. In the power plan settings, it would appear like this if your HDD is set to "NEVER" spin down.
Checked the situation, it isn't the performance plan. I use this drive to install Linux ISO images, which might explain why it doesn't shut down. I didn’t save anything but performed a speed test and found around 1MB/s. When I removed the other drives, everything worked fine. Could be a power supply or heat/vibration problem—there are four drives in a stack with limited airflow, and I have an 8TB drive arriving soon. I might replace some smaller drives to consolidate storage.