Option/speed Q's about best configs to upgrade early 2008 Mac Pro 8-core to SSD I'm a first-timer on here.

I too have an early 2008 MacPro 8-core 2.8ghz with 16gbRam and stock Radeon 2600 Vcard. It's fairly well configured, but I'm sure that can improve response for a reasonable purchase, which bring me to this inquiry.

The idea of using a 1tb SSD drive as a Boot drive to boost my Mac's overall response is exciting because this thing is a dog, even on Yosemite. What I don't know is if that will speed things up in general (and hopefully Photoshop) better than maxing my RAM.

My deeper Question here is which option would get me the most speed for the $ by:
1. maxing Ram to 32gb for ~$450
2. swap current SATA3 WD Caviar boot drive for an SSD (about same $)
3. add an SSD to my second Optical bay (about same $)
4. add an SSD to my second fast PCIe slot? (possibly more $$ than it's worth?)

I currently work a lot on 400mb+ Photoshop files. I keep the files on an internal 7200rpm SATA2 RAID-0, and use a 10,000rpm SATA3 disc as a scratch space.

Do you think I would see a stronger performance gain not only in finder ops, but also in Photoshop with the SSD vs double the RAM? Hard to know where my response time bottlenecks are in this box.
Would an SSD on a fast-lane PCIcard be better than on native internal bus to drive bays?

Any wisdom on options I've not considered would be deeply appreciated as I'm trying to save this box as I don't have the funds to buy a cylinder MPro or fast iMac.

My setup stats:


Running Yosemite, + background apps like Sophos, Fonts mgmt app, TimeMachine, DropBox, etc. 
RAM: All slots used with 2gb Apple sticks.  
Boot drive: 1tb 7.2k rpm WD Caviar SATA3/64cache containing only OS system, iTunes, etc. Only half space used. Kept optimized with DiskWarrior. 
Internal 2tb 7.2k rpm Seagate Barracuda SATA2 Raid-0 for the files. Kept less than 70% full and regularly optimized. 
150gb 10k rpm WD Velociraptor SATA3 as a dedicated scratch disk for PS.


thank you!  ~ dave
Maxing out RAM can only situationally improve your performance. If your computer isn't ever using a ton of swap space (less than a gig), adding more RAM isn't likely to help much. The SSD will almost certainly improve the performance of your computer. Yosemite really is designed for SSDs. It seems to do a ton more arbitrary reads/writes to disk during the course of its operation than earlier versions did, so it will be dog-slow on a HDD.

As for the SSD on PCI, that is definitely the better solution. SATA 2 (which the 2008 Mac Pro comes with) is far too slow for the faster SSDs. There's little point in hooking up a modern SSD to that. PCI should be able to handle it.