HDD Speeds very inconsistent (HD Tune)

Solution
Welcome to the TH Community, @NoreNZ!

I'd recommend checking how the HDD would perform if you connect it using a different SATA cable and to a different SATA port on the motherboard in your computer. If you have access to another PC, you could plug the drive there as well and see how it would behave in the other system.
I'd also strongly recommend you backup all important data from it somewhere else before proceeding with the troubleshooting. This is the surest way to avoid any potential data loss. Better safe than sorry, right? :)
I'd also suggest running the HDD manufacturer's brand-specific diagnostic tool and/or checking the health tab in the benchmark utility you used. Posting a screenshot from there would be really...
Welcome to the TH Community, @NoreNZ!

I'd recommend checking how the HDD would perform if you connect it using a different SATA cable and to a different SATA port on the motherboard in your computer. If you have access to another PC, you could plug the drive there as well and see how it would behave in the other system.
I'd also strongly recommend you backup all important data from it somewhere else before proceeding with the troubleshooting. This is the surest way to avoid any potential data loss. Better safe than sorry, right? :)
I'd also suggest running the HDD manufacturer's brand-specific diagnostic tool and/or checking the health tab in the benchmark utility you used. Posting a screenshot from there would be really helpful, too.

Hope this helps you. Keep me posted with the troubleshooting!
SuperSoph_WD
 
Solution