Installing three SSD drives on Mac Pro

Question

Hello,
I followed the advice given here and bought 3 Samsung 840 SSD drives for my Mac Pro. Two of them are 120GB and one is 250GB.
I also purchased a Tempo SSD Pro 6GB/s SATA PCIe Drive. Only one of them (that holds two SSDs.)
I plan on using:
     • one SSD for the OS and APPS
     • one SSD for a PS scratch disc
     • one SSD for the photoshop, premiere pro, and after effects files I'm currently working on.
I figured I'd keep the 1TB HDD currently used in the computer to store all my other files.
I also have a 1TB seagate extrenal HDD that I would like to set up as a back up or time machine.
Does this sound good?
If so, which SSD do I install in my regular sliding drawer bay? I have 2.5" - 3.5" adapter.
Which two do I install on the PCIe card?
Which on do I use for what?
As you can see I'm clueless. Lol
Here are my specs before adding the SSDs.
Mac Pro
Mid 2012
Processor  3.33 GHz 6-Core Intel Xeon
Memory  48 GB 1333 MHz DDR3 ECC
Graphics  ATI Radeon HD 5870 1024 MB
Software  OS X 10.8.4 (12E55)
Storage  1TB Sata disc (423.26GB free),
               1TB External USB Disk freeAgent GoFlex Drive (988.58 free)
P.S. I'm unsure about being able to install my current O.S. on the new SSD. When I bought the Mac Pro it had an older version of OS on it with a free download of the new OS. So the disc will only have the older version. Will I have to pay for the newer one or can I somehow copy it from the current HDD drive it's installed on?
Thank you so much. You have already been a HUGE help in the past posts and look forward to your wisdom.  8 )
Matt

Answer 1

Clone the system to the SSD you plan to use for system.
How much disk space is your system using now? w/o incl. anything in /Users, so just system.
If your system uses 60GB you want to use the 240GB SSD.
I think 120GB is on small side for scratch alone.
move projects to scratch array when you want to work on them:  "Work disk + scratch" is fast. Then move them off the array, erase the array, and start a new project.
I would try the 2 x 120 SSDs on PCIe 6G as scratch and see how it feels and works.Try and test.  No harm. I think that is what most people do, they experiement and try out different setups to find the one that works best for them.
Important: Have a clone of the system and be ready to restore or move it around as needed.
Install TRIM Enabler of course.
SSD Maintenance
Samsung recommends setting aside 10% for over-provisioning.
Their Windows utility, shame there isn't a Mac version.
#2: Try system on 120GB in drive bay with an adapter
With that then use the other two on the Tempo.
Those could be one large 360GB volume JBOD.
You will have to see how much your scratch space gets used.
I would have argued for 3 x 240GB SSDs. More flexible. Better SSD design - slightly. Adds $140 to the price, even if you had to wait to get 3rd one;
#3  get 2 x 240GB for scratch and projects and 1 x 120GB for system (if your system is less than 50GB)
I doubt you will find the difference of the system on the Sonnet Tempo a deciding factor.
The Sonnet Tempo Pro is for higher I/O RAID, both Tempo cards support 2 x SSDs (I have the cheaper one)
http://www.amazon.com/Samsung-Series-120GB-internal-MZ-7TD120BW/dp/B009NHAF06/
PS: You have Mountain Lion. Buy Carbon Copy Cloner and it will clone the system and create the recovery volume also so you should not need to redownload 10.8.x - and you do not need the DVD with 10.6.4 again.