Some SSD issues

That is your problem. Perform a clean install and you will see the performance increase you are expecting.

 

Some things to check:

1. Launch System Information (found in /Applicaitons/Utilities/) and click "SATA/SATA Express" on the left pane. Look at the Link Speed to see whether the SSD is running at SATA I, II, or III speed. I purchased a Toshiba SSD that refused to run at anything other than SATA I speed in my MacBook and performance was terrible.

2. Launch System Preferences and click "Startup Disk". Make sure your SSD is selected as the startup drive.

3. Look for Blackmagic Disk Speed Test from the Mac App Store (it's a free app) and use it to see how your SSD is performing.

 

Did you install Trimenabler? If you haven't I would try it out, may help.

 

I'd recommend that you start from scratch with a clean install...

Upon installation make sure that you enable trim. There are various posts on this forum explaining how to do that based on the OS you install.

Hope that helps.

 

Mate, i installed a 850 EVO in a MBP yesterday and am having issues also.

1) It wouldn't allow an install from USB drive. Could only do it via Restore from time machine.

2) After the above it ran horribly. Hanging at boot sometimes (had to force restart), beachballs as far as the eye could see, apps crashing etc.

3) I booted into recovery and reinstalled OSX from there (6 hour download) and it actually ran perfect!!!!! Clean install obviously......For 12 hours then it just strangely stopped booting up entirely. It gets to the apple logo but then screen flashes, goes black and it turns off.

I know the drive isn't dead as it boots to recovery. Disc utility says it can't verify and won't repair either. In disc info it's also showing the disc is no longer writeable and also isn't journaled.

I have no idea what is causing the problems now. Clean install seemed to fix initial stability problems but now it's just dead.

I am tearing my hair out.

 

I'm reinstalling again now. Did you use the new sudo forcetrim command in 10.10.4?

 

Actually, the reason you're getting the long pause before the Apple logo is that your machine is searching for your old drive, before deciding to boot off the SSD. Reinstalling will fix it, but you don't have to (for anyone else experiencing this). Just go into System Preferences -> Startup Disk and select your SSD (it may already appear to be selected - just do so again) and then reboot.

Trim is not going to speed up a freshly installed drive - even if it's been cloned from an older machine.

(and please, nobody suggest "Repair permissions" or I'll have to rant about why that is voodoo ;-)