will a samsung 850 pro ssd work with yosemite?

I don't see a performance improvement after switching out the main HD in my late-2009 Mini for a SSD. I put the old drive in a bay and installed it I'm place of the optical drive. Could that be causing the slow-down?

FYI: I am booting from the SSD, not the old HD in the new bay.

Thanks

2raj,

Select the apple ar the top left hand corner of your screen. This will open a window where you want to select 'About This Mac'. Next select the pushbutton 'System Report'. On the left side you should now see a column of various hardware components, select SATA/SATA Express. Now you should see NIVDIA rows and SanDisk plus your old drive at the top of the window. Select each of the NIVDIA rows, one at a time. You should see:

Link Speed: 3 Gigabit

Negotiated Speed: 3 Gigabit

If your negotiated speed is less than link speed, your old hard drive is pulling you down. If that's the case consider connecting the old drive via USB.

For me, the SSD speed was an increase in performance but without the optical drive, my SATA connection doubled in speed.

@ApexRon Thanks!

I checked the Link Speed and Negotiated Speed and what's strange is that it's showing the Negotiated Speed for the SSD at 1.5 GB, but the old HD in the adapter/optical bay is showing at 3 GB.

Why would the old drive in the adapter/optical bay be 3 GB. I would have expected it to be at 1.5 GB as well.

Would it help to swap the drives and put the SSD in the adapter/optical bay?

it's an issue with the Nvidia MCP79 controller, same thing happened

to me. funny thing is sometimes it will show a negotiated link speed

of 1.5 but if i restart a few times (checking each time) it will go back

to 3Mbps and stay there until the next restart !

i even verified this with blackmagic disk speed test.

Pram wrote:

Christopher Breen has an article today in Macworld explaining that most SSDs will not work with Yosemite. To paraphrase Mr. Breen, Apple's TRIM technology doesn't work with third party SSDs, and, while you could use Trim Enabler to make TRIM work with your drive in Mavericks, Trim Enabler modifies kext files and Yosemite will not run with modified kext files. The only workaround is to globally disable kext signing, which is not recommended for security reasons. Has anyone had any experience with this issue? I just purchased a third party SSD for my MBP. Thank you for any input.

Cheers, Peter

You're out of date, only 10.10.1, 2 and 3 were affected by the kext signing issue. Current software (10.10.4) is not, future versions will also not be affected.

Try to post current info rather than old. (or come back and update the info)

Chris Breem is a nonce (look it up) he sells column inches, that's all.

Thanks Sonia. So, is there a solution to this because I am not really seeing any improvement in performance between booting from my old HD vs. the new SSD.

Also, what seems to be the consensus on enabling TRIM, should it be enabled or not?

2raj wrote:

Thanks Sonia. So, is there a solution to this because I am not really seeing any improvement in performance between booting from my old HD vs. the new SSD.

Then something is very wrong, the difference is significant, not something you would miss. Download a copy of BlackMagic disk speed test and run it, post the results here.

you should definitely run trim ! use the "sudo trimforce enable" command

in terminal.

nothing is technically wrong, the problem is a compatibility issue with

the Nvidia controller. sometimes it will negotiate a link speed of 1.5Mb

and other times 3Mb i have run Blackmagic on both occasions and

when it shows 1.5Mb i get 107/145 and when it shows 3 i get 209/263

even at 1.5Mb there is a significant speed difference compared to my

old 5400 hard drive ! it boots faster, apps open quicker, system prefs

opens much quicker.

@Sonia Is it better to use the Terminal command than use the Trim Enabler app? and is it safe to run the command on a boot drive that contains active data?

@Csound1 Thanks! I'll run the speed check and see what it says.

What's weird is that my System is always running around 99% memory usage with only Safari and Mail running, and runs sluggish most of the time.

I have already maxed my RAM to 8GB and thought switching from HD to SSD would help. I have a 512 GB Samsung 850 SSD and it's only about 50% full, so there should be enough swap space on the drive.

yes, the sudo terminal command enables trim natively compared

to using a 3rd party app. turn off trim in trim enabler and restart.

then delete the app and run the terminal command and restart

again. open system report and you should see trim enabled 🙂

install Memory Clean (free from app store) and keep track of your memory usage,

run the cleaner if it gets low.

I haven't used Trim Enabler yet, so TRIM should be off by default, correct?

Do I just enter "sudo trimforce enable" in Terminal when it opens, or is there more to it such as telling it which disk etc?

Sorry, when you said "I am not really seeing any improvement in performance between booting from my old HD vs. the new SSD" I assumed that you meant it. Your old drive could manage 35 to 55 MB/s, even on a 1.5Gb/s bus the SSD can do twice that, you should still see the difference.

FYI, the link speed is not 1.5Mb, it is 1.5Gb/s, the drive speed (max) is 550MB/s, note the letter case Mb is not the same as MB.

Finally please note that this was not in reply to you so please, pass it on.