Disk Configurations

Question

I'm building a new system and have some questions about what sort of disk configuration to put together.  Probably about 90% of my source will be AVCHD (more details in my earlier post).  The articles on this forum are great and have been very helpful but I'm still confused.  The Generic Guideline for Disk Setup talks about distributing access across as many disks as possible but then shows all configurations with more than 4 disks as placing everything except the OS, programs, and pagefile on the same RAID.  A file is distributed across multiple disks in a RAID but it's one logical drive so there must be head contention if more than one file is needed at the same time from that RAID.  Wouldn't a setup like this work better?
C: [1 Drive] OS, Programs
D: [RAID 3] Media, Projects
E: [RAID 0] Pagefile, Media Cache
F: [1 Drive] Previews, Exports
Would there be any problems having multiple RAIDs?  In the above example, the RAID 3 would require a hardware controller and the RAID 0 could run off the ICH10R on the motherboard.  Can  ICH10R support multiple RAIDS (more than one RAID 0) and can a hardware controller (say, an Areca) support more than one RAID?  If so, would it be better to run both the RAID 3 and RAID 0 in this example off the Areca?
To RAID or not to RAID has been helpful but I'm still not clear on everything.  What are the differences between an inexpensive controller like the Areca ARC-1210 and the more expensive models which can cost 4 times as much?  Obviously the more expensive controllers have faster processors and more cache but do you get 4 times the performance?  I'm sure a high-end controller would be helpful if you're editing 4K files or uncompressed HD but I suspect it's not worth the expense for a mostly-AVCHD environment.
What about using RAID 0 for source media?  I understand the likelihood of problems increases with the number of disks but what does that mean in the real world?  I've been using my current drives (Seagate SCSIs) for about 7 years and have never had a problem.  In fact I've owned computers with hard drives since the early 80s and don't believe I've ever had a disk fail on me.  Of course everything needs to be backed up but how often might I be rebuilding a RAID 0 due to disk failure?  Maybe I've been very lucky or maybe "they don't build 'em like they used to".
I've been using (parallel)SCSI for over 10 years but no longer believe it's cost effective.  It seems like adding more SATA drives to a RAID would be cheaper than expensive 15K RPM SAS drives.  Does everyone agree with that?  Also, SAS drives are only available in much smaller capacities than SATA drives.
A hardware controller is required for RAID 3 and strongly recommended for RAID 5 but do they offer an advantage for RAID 0?  What about for RAID 10?  One advantage would be providing extra ports since most motherboards only provide 6 SATA ports.  Does one motherboard offer any better SATA and RAID performance than any other or are they all about the same in that regard?
Is there any advantage to external RAIDS other than convenience in moving data from one computer to another?  It seems like a controller directly on the bus would be faster than one connected externally.
Is there any disadvantage to running SATA 3 drives on a SATA 2 controller?  A possible advantage might be the larger cache that some SATA 3 drives have.  Would a 64MB cache help much over a 32MB cache?  I've also heard SATA 3 can increase burst speeds.  If I have two SATA 3 ports, and I'm using one on an SSD for the OS, would it help to use the other port for another drive or might that take away bandwidth from the SSD?
I've run across some things (don't have links handy) that indicate there may be problems with drives larger than 2 TB.  Is this just for single drives larger than 2 TB, RAIDs larger than 2 TB, or am I confused and this is not an an issue?
What about specific drives that are quiet and perform well?  Quietness is important to me and I worry about building a box, with as many as 10 drives, sounding like an airport runway.  I've heard the Caviar Blues are quieter than the Black but I don't think they perform as well.  I've heard Samsung F3 are both quiet and fast and that's what I'm leaning towards at the moment.  What's with the F4?  Samsung's site says it's “Independently tested as the fastest 3.5” HDD available” yet it also refers to it as an “Eco-Green HDD”, which usually means slow.
Should I use different drives in RAIDs than standalone?  I've heard “enterprise” models are better for RAIDs because of differences in their firmware error recovery.  These sources say “consumer” models are more likely to time-out in a RAID because they have more aggressive error recovery.  Is this true and should be a concern?
Roy

Answer 1

I'm looking forward to an answer too, because I have some of the same questions. I'm currently working with a systems integrator on a quote, and we are hashing out some details about a few things.
I do a lot of uncompressed 10-bit, as well as some 1080p60 projects. So, for the RAID, to date, I'm going for an Areca ARC-1880ix-16. Funny thing is, there is not much price difference between the 12 and 16 port model. So I'm going to go with the 16-port model, and upgrade the cache to 4GB. Seems well worth it. I'll probably start out with an 8 disk RAID setup, and upgrade it n the future if need be.
We did toy with the idea to build the RAID around SSDs.... Ouf, imagine having an 8 SSD RAID! (Corsair SSD Force Series 3). But realistically, I'll most likely go with normal SATA III drives. And since they are so inexpensive, I'll probably fill it to the brim. Or most likely, the capacity that the case can handle.
But Roy has a good point. What about distributing the load on the array? Would it be more appropriate to make 2 RAID groups on the card? To balance the traffic of the media, cache, previews, pagefile and export?
Roy, I can start answering some of your questions though (My years of being a PC tech comes in handy sometimes, hehe)
Would there be any problems having multiple RAIDs?  In the above example, the RAID 3 would require a hardware controller and the RAID 0 could run off the ICH10R on the motherboard.  Can  ICH10R support multiple RAIDS (more than one RAID 0) and can a hardware controller (say, an Areca) support more than one RAID?  If so, would it be better to run both the RAID 3 and RAID 0 in this example off the Areca?
From a technical standpoint, there are no problems running multiple RAIDs. But there would be a performance drawback if the RAID was software only (OS managed). Thankfully, on-board RAIDs do help, but there is still some CPU overhead to deal with on-boad RAID5, and very minimally RAID 0. Having a RAID card is always the better option if you can afford it. The performance, manageability and flexibility are unmatched, compared to any on-board motherboard RAID controllers. RAID 0 is simple and does not need much resources. So, yes, you could run the RAID 0 from the on-board controller of the motherboard. It would theoretically "offload" the 8x PCIe lane from extra traffic, but practically, I seriously doubt the disk I/O would exceed the PCIe bandwidth in the first place.
What about using RAID 0 for source media?  I understand the likelihood of problems increases with the number of disks but what does that mean in the real world?  I've been using my current drives (Seagate SCSIs) for about 7 years and have never had a problem.  In fact I've owned computers with hard drives since the early 80s and don't believe I've ever had a disk fail on me.  Of course everything needs to be backed up but how often might I be rebuilding a RAID 0 due to disk failure?  Maybe I've been very lucky or maybe "they don't build 'em like they used to".
I use P2 media. So I practice double copies. A working copy on the computer, the other on an external HD as a backup copy. Everyone using solid state media to record on, should do the same. Having said that. You know what RAID 0 means?  Zero chance of data recovery if 1 drive fails. The more drives in a RAID, the more likely a problem can arise. Packing drives tightly together will produce more heat if not well ventilated, and will reduce the life expectancy of any drive. I have come across some bad disks in my 20+ years dealing with computers as a tech. Not that many, but enough to not trust them, and enough to practice backups even if I had a RAID 5 or 6 (and a hotsparet). Even though I have a backup copy on an external drive for my source media, and even though I try to backup as often as I can, I can still loose other things (ancillary files) in my hypothetical RAID 0 media drive. Worst case? I could loose a day's worth of work, plus what ever time it takes to rebuild and restore everything from the previous night's backup (if I didn't forget). Time is money for most of us. And investing in a proper editing system is something I don't take lightly.
A hardware controller is required for RAID 3 and strongly recommended for RAID 5 but do they offer an advantage for RAID 0?  What about for RAID 10?  One advantage would be providing extra ports since most motherboards only provide 6 SATA ports.  Does one motherboard offer any better SATA and RAID performance than any other or are they all about the same in that regard?
There are no major advantages to use a RAID 0 or 10 on a standard addon hardware RAID controller, other then to free up ports on the motherboard, or have a higher disk count on your RAID. But higher end RAID cards with bigger cache, will be faster. On-board RAIDs do have some overhead, but for RAID0, it's not as drastic as RAID5. Motherboard SATA RAIDs, with the same chipset, for all intents and purposes, are basically the same performance. There may be small variations from one manufacturer or another, but nothing real world measurable.
Is there any advantage to external RAIDS other than convenience in moving data from one computer to another?  It seems like a controller directly on the bus would be faster than one connected externally.
Convenience, is subjectively proportional to your needs and disk quantity inside the computer casing. hehe What stops me from having more then 16 drives in my system, is the casing size for HDs and possible heat dissipation issues. I try to have a system that is self contained, and avoid using an external enclosure if I can. But regardless, the speed of internal and external ports on a RAID card is the same.
I've run across some things (don't have links handy) that indicate there may be problems with drives larger than 2 TB.  Is this just for single drives larger than 2 TB, RAIDs larger than 2 TB, or am I confused and this is not an an issue?
Not an issue with Windows 7.
Frederic