My personal approach would be:
1. SSD: OS, program files and pagefile
2. Raid0: Media, projects, scratch and media cache (possibly the media cache on the SSD, depending on free space), (nice, compact and easy to maintain)
3. Export to one of these Drobo disks
If you are running out of space (with the 2 x 250 disks), you can consider upgrading them to 2 x 500.
For export there is no need for disk speed, the encoding (CPU intensive) is the most time consuming task and the externals can easily write the results. The media cache is not so easy. It is often accessed, both for reading and for writing. Earlier SSD disks, especially those based on the J-Micron controller, had a serious performance degradation in write speeds after a couple of months, sometimes not even achieving 40-50 MB/s write speed. So it may depend on the complexity of your projects, your workflow and drive usage where you want to place the media cache.
I know this is rather vague, Rob, but the best I can do at the moment.
2. Raid0: Media, projects, scratch and media cache
I disagree with that recommendation. Nothing should be stored on a RAID 0 unless it can be easily recovered. Media is OK, when shooting on tape. You can always recapture. Scratch is OK, because Premiere will just rebuild. Project files aren't such a good idea, nor is tapeless media which often has no built-in 'back-up' for recapture.
Personally, I feel nothing less than a RAID 3 should be used for tapeless media editing. (Or RAID 5 if you card doesn't support 3.) You need that built-in redundancy, else you stand to forever lose everything you shot that's stored on that drive.
One of the Drobo disks is used for backup, amongst those files the project files.
Adobe needs to start paying you =)
Where then will the bottleneck be with tapeless media, in terms of DISK performance.
All these guides say, setup your scratch disk on a different drive then where your media is? Is this no longer true for tapeless media?
Also, like you said, the encoder is almost all CPU -- but wouldn't reading from one drive and writing to another improve performance? I'm guessing no, unless the format is something like uncompress HDV? Which i'm not using.
What is the media cache used for? Does that create a large footprint on the drive?
My main concern is speeding up the encoder. I have no issues with importing/editing projects. The laptop is an i7-960 with 8gb of ram.
My 2nd concern is filling up the SSD with cache data. The free space available is only around 75gb right now.
When i setup my scratch disk to point to my raid, it did not seem to place anything on this drive during editing or encoding. So, I don't really know what it's being used for?
p.s. thank you jim for your concern also. I know anytime someone mentions raid0 someone else says STOP! but, I think if you backup automatically then it's safe. The data is not destroyed on the SD cards until its backed up on the drobo.
The data is not destroyed on the SD cards until its backed up on the drobo.
A good policy.
There is a theoretical advantage to having the media and exports on separate drives. It'll be faster than reading and writing to the same drive. But unless you're doing a DV export from DV media with no effects, the performance difference will be slight by comparison. Most exports are likely to be dependant upon the CPU for their rendering time rather than the disk setup. So the short answer is, go with separate drives if you can, but don't get stopped by not having separate drives.
To put this into more perspective, the basic recommended setup is three drives minimum. A System drive for OS and programs, a Project drive for project files and scratch, and a Media drive for...well I think you can deduce that. If you can, go for a fourth Export drive. But do try and start with the basic three at least. (Backup drives are in addition to those three/four listed above.)