[bladesmith]

One thing I have found not pleasing about Yosemite. Is the new OS will not allow third party drives (SSD/ext. drives/ramm).

 I have read articles about customers trying to install new SSD with Yosemite and it doesn't work.

I personally have tried installing third party RAM models in my Mac Mini and they won't work, even if you get them very good quality venders. I tried going from two 2GB modules to two 4GB modules, will not work, with Yosemite.

(Modified: post #27 might fix some troubles with adding ram.)

[scb]

One thing I have found not pleasing about Yosemite. Is the new OS will not allow third party drives (SSD/ext. drives/ramm).

 I have read articles about customers trying to install new SSD with Yosemite and it doesn't work.

I personally have tried installing third party RAM models in my Mac Mini and they won't work, even if you get them very good quality venders. I tried going from two 2GB modules to two 4GB modules, will not work, with Yosemite.

I mave a mac mini with an ssd and upgraded ram and it works fine with Yosemite. Ram is from Trans Intl and ssd is plextor

[bside123]

I'm also running Yosemite with 16gb RAM on my MacBook Pro without a problem. Upgrade RAM is from Crucial.

[cody69]

I'm also running Yosemite with no issues at all with my macs, which all have been upgraded with Crucial memory to 12 or 16Gb... macbook pro, mac mini and imac. I've also swapped the HDD to a SSD drive in the macbook pro... again, with no issue.

My experience with Yosemite has been positive -- has been rock solid for me from the start.

[Crimson]

No issues here with external HDs or upgraded memory.

[bladesmith]

This is what I have found..


http://www.larryjordan.biz/caution-ssd-drives-and-yosemite/

If you disagree with his findings, you are welcome to email him and discus it..

Just thought I would pass it on.

(Modified: see post #27 for help installing Ram modules. )

[AllynW]

Before Yosemite I purchased a OWC branded SSD.  Nowhere in the documentation did I see warning about using “TRIM”.  I installed trim and within weeks the drive died.  My guess is those OWC folks are spending a lot on warranty replacement drives.   Apple is a selfish company and does not want some other company getting hardware relate money.  I have Yosemite on two Mac’s with non Apple SSD drive.  I learned my lesson regarding “Trim”  but if I lose another SDD drive, I am going to Linux! 

[bladesmith]

Okay,

This is the way to resolve issues when installing new (fickle) RAM modules in Mac's. You won't find this anywhere. And it took me a lot of effort,  talking to a lot of techs, to finally get this corrected.

But, if you are having trouble installing fickle RAM, you must reset/clear the NVRAM. Using your "Command, Option, P, R" keys, held down while powering up.

Resetting PRAM and NVRAM
1.   Shut down the computer (would already be off during install)
2.   Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.
3.   Turn on the computer.
4.   Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.
5.   Hold the keys down until you hear the startup sound ("bong") for the third time.
6.   Release the keys.

The trick is, you might need to repeat it several times. Until it doesn't restart when attempting the reset/clear. Then new modules will be accepted freely, by your Mac.

Good luck....

[brj]

One thing I have found not pleasing about Yosemite. Is the new OS will not allow third party drives (SSD/ext. drives/ramm).

 I have read articles about customers trying to install new SSD with Yosemite and it doesn't work.

I personally have tried installing third party RAM models in my Mac Mini and they won't work, even if you get them very good quality venders. I tried going from two 2GB modules to two 4GB modules, will not work, with Yosemite.

(Modified: post #27 might fix some troubles with adding ram.)

To be clear, Yosemite doesn't allow unsigned (unapproved by Apple) 3rd party drivers.  It does allow 3rd party (hard) drives.  (This is another by-product of Apple trying to further secure the OS, specifically any software extensions that touch the OS kernel.)  Now if a new drive needs a 3rd party driver to function properly, then you might have an issue if the vendor hasn't gotten it signed by Apple.  A lot of hardware doesn't require this, however, including most SSDs.  (Some do only to enable certain functions, ala TRIM, which is where the confusion seems to come from.)

Personally, I installed 16GB of Crucial RAM in my 2011 MBP just over a year ago.  (Running Mavericks at the time.)  No issues, though I did ensure that the RAM timings met or exceeded Apple's specs.

Now running Yosemite, I installed a Samsung SSD last weekend.  No issues, aside from having to remember the EFI password to boot for the first time following the install and data transfer, after which I had to boot into the rescue partition in order to tell Mac which drive to use as the startup disk.  Other than that, it went smoothly.  I won't have TRIM support enabled because that would require Samsung to get a special SSD driver approved, which they have yet to do, but TRIM (an OS mechanism to facilitate garbage collection on an SSD) isn't really that critical anymore, as most SSD controllers implement their own form of garbage collection these days.  As long as you don't let the drive get too full, the built-in garbage collection routine will have the space it needs to swap data around on its own.

[mresseguie]

Well, I installed/updated to Yosemite a few days ago, and I don't like it. Oh, okay.  It's mostly fine, but two things I really dislike are there is a one or two second pause from when I type to when it appears on my screen (WTF?), and my internet has slowed way down. I will call Apple Support tomorrow for help as I don't know what the hell is causing it.

In the future I will simply ignore the damned upgrade until I am forced by Apple to install it. I only switched to Apple last year thinking I was going to be free of irritations like this......PITA.