PC is starting to annoy me and Caching isn't working

Hello, once again I am having more problems with my PC I built.

I think its probably time to list everything I have done, everything I have and then let you guys tell me what to do because everything I do just makes everything worse. So to start with I started building my PC near the start of my summer holidays and at that point these are all the parts I had:

- PC-Q18B Lian Li Mini ITX case - 1 Samsung 840 Series 120GB SSD - 1 1TB WD Black HDD - Intel 3rd Generation i5 2500K 3.4GHz - Corsair Builder Series CXM 750W Modular 80 Plus Bronze Certified PSU - Gigabyte Z77N-Wifi Mini ITX motherboard - Adata 2G Gaming Xpg Series 8GB Momery Module - GTX 660 Ti SC EVGA GPU 3GB of DDR5

Since getting all those parts I built my PC and installed Windows 8 Pro on my 1TB Hard Drive, once that was installed I used Intel's Rapid Storage Technology software which turned my 120GB SSD into a Caching drive to improve read speeds of my computer and it worked perfectly, my PC was super snappy and just worked a treat. Then I started noticing that my PSU was making funny noises and because of this I sent it back for a refund (they didn't do replacements). Whilst not having a PSU I went on the Tek Syndicate forums to ask whether I really needed 750W and the conclusion was I would probably be better off with 650W, because of this I went out and bought the Seasonic 650 W M12II Bronze Series Modular Power Supply which featured in Logan's epic mini ITX build video.

Once the new PSU was installed I started to get boot up problems, it would boot all the way to the log in screen then crash causing it to switch off and start booting up again and the second time it wouldn't have any problems. I started to inquire about this on the forums and after fiddling around myself I discovered that once the SSD was completely removed everything worked fine, be it a little slower but all boot up processes worked without any errors. I took this to mean that my caching drive I had set up using Intel's RST had gone wrong some how and needed to be re-installed, so I uninstalled the software by Intel, formatted the SSD and tried setting up caching like I had done when I first built my desktop but unfortunately it's no longer allowing my to set up caching but has stopped the boot up problems.

Again I resorted back to the Tek Syndicate forums in search of some guidance, since then have given up with Intel RST and have tried out a piece of software called PrimoCache which might have improved performance but its significantly slower than when I first built my PC still.

I don't know what to do. I want the performance which I had months ago but I can't get Intel's Rapid Storage Technology software to allow me to set up caching again. Do I need to do a clean install of Windows and restore my BIOS to factory conditions to make the software work again? I don't want anything fancy, I just want it how it was! 

Thanks in advance.

With my cache drive the sata config in the bios needs to be on RAID for it to work properly.  I would reset to factory defaults in the bios change the sata mode to raid and set the 1tb to first boot drive(so windows starts).  Then in windows try to re enable the ssd caching 

Personally id just ditch the caching software all together and just install the OS directly to the SSD, i think caching software is only useful if you have a really small SSD like 60G, with a 120gig SSD you have enough room for the OS and a few select programs/games and anything massive or not used much can go onto the large storage drive. 

I have a Velociraptor 300G HDD, its at 178G used, thats windows 8,tera,guildwars2,Aion,CS:GO,KerbalSpaceProgram,WarThunder,GRID,TS,Vent,Mumble,Skype,Chrome blah blah and alot of other stuff, so a 120G SSD can hole a hell of alot of stuff before you really even need to worry about space.

Shall I use Intel's Rapid Storage Technology to re-enable SSD caching? 

I think I remember this. By chance have you checked if there is any programs that boot on start up that are not needed? It could be a useless program that is sucking resources at boot.

Such as defrag schedulers, updaters, or av scanning.