I switch back to one hard drive from one SSD and one harddrive. Since my SSD died.
Few months has pass by and I am not sure if my harddrive is working an optimal speed. Only thing I change in the bios is changing harddrive setting to IDE to ATA. Which is the prefer setup for a single harddrive like this :
Seagate Barracuda 7200.12 ST3500418AS 500GB 7200 RPM 16MB Cache SATA 3.0Gb/s 3.5" Internal Hard Drive -Bare Drive
I believe you probably mean you set to "AHCI" mode?
Anyway, it's very unlikely that your hard drive is running slow. It's likely that you are spoiled by the speed of the SSD.
Even my Velociraptor seemed slow after my SSD.
Is your SSD under Warranty still?
*In case you didn't know this, there's plenty of free software that can help you CLONE from one drive to another. So if you get another SSD, or a replacement, you can simply CLONE without reinstalling Windows completely.
EASEUS has some free software.
SEAGATE has some free software. It's actually "Acronis True Image" but it's not labelled that way. I forget the name at the site.
Anyway this software has a CLONE feature:
1) turn off PC
2) hook up SSD
3) in Windows, flash the SSD's firmware if newer exists
4) Start Acronis True Image and choose CLONE
5) CLONE from hard drive as source to SSD as destination
6) POWER OFF and unhook the hard drive connections (should boot from SSD now)
Then TEST for a while. Once happy you can reclaim the hard drive by formatting it. Simply:
1) power off PC
2) hook up hard drive
3) boot to the BIOS only
4) make sure the SSD is the boot drive (not the hard drive which is still bootable)
5) in Windows you can now FORMAT the hard drive (verify again that it is the hard drive)
*Occasionally make backup IMAGES of your C-drive (Windows etc) using the free Seagate version of Acronis True Image.