...now that SSDs have become MUCH cheaper and more reliable.....they must be considered in your thinking. It is now possible to have a very fast drive system using only SATA III SSDs as the working drives...while editing... and conventional hard drives as backup and storage of completed work. This way , an expensive RAID controller card can be avoided. However, if you are going to need large volumes while working, its back to a RAID solution !!
What you need is dependent on the codecs you will be editing and the disk transfer rate needed to edit those codecs smoothly, PLUS...the size of your projects. Visit the "Tweakers Page" on the PPBM7 website to learn more about what is needed. Many beginners are editing HIGHLY compressed codecs,like DSLR footage from Canon ,or, Go Pro video cameras. These codecs do not require a large, sustained data rate....due to their heavy compression. They require a POWERFUL CPU and GPU to process the compressed video while editing. If you "transcode" this footage into the "CPU friendly" Cineform, THEN you will need a faster drive system !!
If you are using these types of codecs, a simple solution would be to have : "C" drive as a 256GB Samsung Pro,or, Crucial M550 . ONLY OS,programs and page file would be on it. "D" drive would be a "scratch drive".....another 256GB Samsung Pro,or, Crucial M550 exclusively used for all previews, PPro cache files, and media cache files. If you are using After Effects, this drive would also be your "global performance cache" to speed up AE. You may also "export" to this SSD.....to speed the process....as the files on this drive are not used during the export process. Your "E" drive would be where all your media and PPro project files would live.....all your video clips, photos,music,etc. Obviously, this data would be very important and would need to be backed up. The data on your "D" drive can safely be lost,as PPro would automatically re-create it, ( except any finished exports put there ). A 500GB or 1 TB Crucial M550 SSD would be ideal as the "E" drive.....it would provide the matching speed to all the other SSDs in your system, ( 4 to 500 MB/sec. read AND write ), and would be WAY more reliable than a RAID 0 array of HDDs off the motherboard.
Considering the movement toward 4K, and the just released "2014 Creative Cloud" PPro.....( which appears to DRAMATICALLY speed up 4K processing....but, NOT AVCHD ! )...you may want to have a machine that can handle the 4K.
Using Samsung Pro series SSDs,or Crucial M series SSDs ONLY is important !! These particular SSDs have Marvell controllers in them, (NOT Sandforce), which handle "incompressible data"....like digital video...MUCH better than cheaper SSDs. They sustain better WRITE speeds and perform better after reaching their "steady state".
Of course, to save money, you could always make your "E" drive a RAID 0 of two identical 7,200 rpm HDDs off the motherboard....the disk rate would be about 260-300 MB/sec. However, you would be at risk of losing all your data if one HDD failed,so, you would need a constant backup of it onto another large HDD. Drive speed is important. A single HDD running at 7,200 rpm is not going to provide the performance needed for multi-stream editing and future demands....it will be come a speed bottleneck at 130 to 150 MB/sec....not to mention the speed getting CUT IN HALF by "fill degradation" and having to defragment it all the time !!!...
So, you may want to use ALL SSDs for your WORKING drives......then, have one or two large conventional HDDs as backup drives and storage.
Hmm, so I'll be editing a lot of weddings. For sure I'll probably get another SSD for preview, cache files. But for E drive, to be more safe should I do raid 10 of (4) 7200 HDD? I just don't want to loose anything while I'm editing. And all the files will definitely be store somewhere else too.
BTW I already bought 2 WD black without knowing it aren't suitable for Raid. Should I return it?