The first two SSD drives you mention, are utterly inadequate.
As for the rest, Adobe applications really want to reside in your boot drive, where the OS resides.
Photoshop scratch works best on a dedicated, physically separate hard drive.
The rule of thumb I follow to figure out scratch space says to figure on 50 to 100 times the size of your largest file ever multiplied by the number of files you have open. I have seen the scratch file exceed 800 GB once, an admittedly rare occurrence, but it often exceeds 200 GB when stitching large panoramas and the like.
As an example—and stressing that I'm aware that others have even more scratch space than I do—I keep two dedicated, physically separate hard drives as my primary and secondary Photoshop scratch disks and a lot of GB free on my boot drive for the OS. I also have 16 GB of RAM installed.
Additionally, if you only have a single HD, i.e. your boot drive, you'd need it to be large enough to accommodate both the swap files of the OS as well as Photoshop's scratch.
Thanks for your message. The first two SSD drives are inadequate for what? For anything at all? Or for scratch and caches? Even the 120GB 6G SSD is big enough to serve as my startup drive with OS, apps, home folder, etc. with room to spare. Which leaves all 240GB of the other 6G SSD free for scratch and caches. ALso available for scratch and caches is whatever's left open on the 960gb Accelsior SSD (not being used by DNGs and TIFFs). I know that 240GB on its own is not enough to handle some scratch space needs, but It's rare that I do panoramic stitching; I usually have open at one time only one 36MP file with somewhere between one and six layers. I'm not claiming that what I have on my fastest drives is anywhere near enough space for scratch; rather, I'm asking for advice on how best to use the drives I do have. I should make clear that I have several TB of free hard drive space, connected via eSATA, that can serve as additional sources of scratch space.
I'm able to fit my OS and all apps and email and such on the 120GB SSD, so it seems I might as well use the 240GB SSD for something else. Do you think it's faster to just have scratch and caches on the 960GB Accelsior SSD (along with the work-in-progress DNGs and TIFFs) than to put scratch and caches on the 240GB SSD? If scratch and caches and DNGs and TIFFs were all on the same drive then they would of course be competing with one another for bandwidth, but perhaps the read incompressible rate of 640 MB/s and write incompressible rate of 400 MB/s of the Accelsior connected via Thunderbolt 1 is fast enough so that there's more bandwidth left over for scratch and caches there than there is on the 240GB SSD with its read incompressible rate of 270 MB/s and its write incompressible rate of 170 MB/s? Any advice on how I can know which way of distributing this stuff is faster? --Mark
For any of the purposes you referenced, except perhaps as image archives if you don't mind getting new ones often, as they fill up.
They're not adequate as my boot drive nor as scratch disks for Photoshop. Remember that the OS needs plenty of available disk space for its swap files.
If your needs are that modest, perhaps asking in a professional-level forum is a waste of your time and mine.
If you don't like my response, you're welcome to your money back: $0.00. Why ask in the first place if your mind is made up.
But I'm not going to waste one second debating or arguing with you.
Hi again station_two.
It seems we have misunderstood one another. When I wrote "Thanks for your message," I was sincere, not sarcastic. And when I asked "The first two SSD drives are inadequate for what? For anything at all?," these were sincere questions, not rhetorical ones: I was genuinely uncertain as to what you meant, and was asking you to help me understand. I had not known that the OS needs plenty of available disk space for its swap files, so it's a good thing for me that I asked you the questions I did: otherwise I wouldn't have learned that. I will try to learn more about it elsewhere, since it feels like you wouldn't want to tell me more about it here. I didn't mean to be claiming that my needs were modest, but even if I had been, I see nothing unprofessional about modest needs. I'm sorry if I have wasted your time. I thought that it was okay to ask questions to which one did not already know the answers here. I didn't dislike your response. I appreciated it. My mind was not made up; nothing in any of my comments or questions implies a made-up mind. One can only convey one's problem through a process of conveying one's understanding or misunderstanding. I conveyed my understanding and misunderstanding in good faith. I wrote nothing in disagreement with you, nothing to debate you, nothing to argue with you. Please don't reply to this if doing so wastes your time. I wish only to express good will. I apologize if I offended you: I did not intend to do so.