RAID advice needed for new system build, please

[Steven Reid]

I've done my homework and decided to build a PC for HDV editing (from a Canon XH-A1 that I plan to get also). While I'm confident in my selection of components, I'm stuck at last, however, on how best to arrange the HDD's. Either this is so simple that it just isn't discussed, or I failed to find posts on topic.

At the outset, I decided to go with a 10k RPM 'Raptor for OS and programs.

For video and other media files, I was planning on RAIDing at least two 1TB drives. Now this is where I may fail to understand: does one capture to, edit on, and render to the same RAID array? On my current system, by contrast, I capture video to X, have music on Y, and then render from X and Y to Z (all single drives).

1. Does this change with a RAID array, such that you can (or should) use the same array for all functions (capture, edit, and render)? If so, then perhaps better to RAID together a few more drives for redundancy?

2. If not, what is a better arrangement of HDD's?

Apologies if this is a dead horse, in which case please direct me to the carcass. ;)

Thanks,
Steve

[Harm Millaard]

You currently have 4 disks. As I understand you, you intend to go back to only two disks (even though one is a raid with two physical disks, but the OS sees that as a single disk). Bad move. Better use the 4 disks as you currently have, but add an identical disk to your X drive and use both in a raid.

[Steven Reid]

Originally Posted by Harm Millaard

You currently have 4 disks. As I understand you, you intend to go back to only two disks (even though one is a raid with two physical disks, but the OS sees that as a single disk). Bad move. Better use the 4 disks as you currently have, but add an identical disk to your X drive and use both in a raid.

Ooops: your reply made me see that I should have written my post better. To clarify, I am dumping my current system, and building a new one. I merely explained my current system setup to test whether I should replicate or modify it in my new PC.

Thus, the new PC will have a dedicated OS/progams drive (C:). In addition, I plan to have at least two HDDs RAIDed together for video and other media. My question is whether this single RAID is sufficient for all purposes (except OS and programs, of course), or whether I need additional HDDs in different configurations. Possible combos I could do are:

- Example 1: capture to RAID, render to a different single HDD?
- Example 2: capture to RAID, render to same RAID.
- Example 3: capture to single HDD, render to RAID?
- Example 4: capture to RAID, render to different RAID?

Are any of these configurations clearly better than the others? Your reply suggests that capture to a RAID is best (examples 1, 2,and 4 above). Right?

Thanks,
Steve

[Harm Millaard]

Steve,

Not one solution is ideal. There are often multiple solutions that are equally good. With current disk prices, I would look at the following setup:

C: OS & programs
D: Raid0 (2x 1 TB) media
E: Raid0 (2x 750G) for projects and scratch
F: single for exports.

If you really want to go all the way, consider a setup like this:

C: 128 GB SSD for OS & programs
D: 8x 1 TB in Raid50 for media
E: 4x 1 TB in Raid3 for projects and scratch
F: 4x 1 TB in Raid5 for exports.

in combination with an Areca ARC 1680iX-16 controller with BBM and 4GB cache.

[Steven Reid]

Originally Posted by Harm Millaard

Steve,

Not one solution is ideal. There are often multiple solutions that are equally good. With current disk prices, I would look at the following setup:

C: OS & programs
D: Raid0 (2x 1 TB) media
E: Raid0 (2x 750G) for projects and scratch
F: single for exports.

If you really want to go all the way, consider a setup like this:

C: 128 GB SSD for OS & programs
D: 8x 1 TB in Raid50 for media
E: 4x 1 TB in Raid3 for projects and scratch
F: 4x 1 TB in Raid5 for exports.

in combination with an Areca ARC 1680iX-16 controller with BBM and 4GB cache.

Hmmm. Thanks very much, Harm. I think the first combination is closer to what I can do. I hate to flaunt my ignorance: I've seen many references to "scratch disks" here, but I've never seen them in connection with Sony Vegas (6d), which I use edit. If I'm correct, then C:, D:, and F: in your first example would probably fit the bill...figuratively and literally!

Steve

[William Meredith]

Be aware that if you use two drives in a RAID 0 array - striping only, they write alternating sectors, e.g., disk 1 sector 1, disk 2 sector 2, disk 1 sector 3, disk 2 sector 4 - etc.

Which means if one disk dies EVERYTHING is gone!

Better is 4 disks in a RAID 10. You get 1/2 the storage but total backup protection.

[Steven Reid]

Originally Posted by William Meredith

Be aware that if you use two drives in a RAID 0 array - striping only, they write alternating sectors, e.g., disk 1 sector 1, disk 2 sector 2, disk 1 sector 3, disk 2 sector 4 - etc.

Which means if one disk dies EVERYTHING is gone!

Better is 4 disks in a RAID 10. You get 1/2 the storage but total backup protection.

Thanks! I like your suggestion, especially after educating myself on how RAID10 works (also confirmed that my desired MOBO supports it). I just revised my parts list to incorporate a RAID10 (1TB HDDs).

Steve

[Mike Bisom]

Let me just add that you need to make sure you are using a hardware RAID, that is you are using a RAID controller with it's own microprocessor. A software RAID really doesn't offer any speed benefits and are difficult to rebuild.

Mike

[Steven Reid]

Originally Posted by Mike Bisom

Let me just add that you need to make sure you are using a hardware RAID, that is you are using a RAID controller with it's own microprocessor. A software RAID really doesn't offer any speed benefits and are difficult to rebuild.

Mike

Thanks. Yes, I appreciate that it should be a hardware RAID. My desired MOBO -- Newegg.com - GIGABYTE GA-X48-DQ6 LGA 775 Intel X48 ATX Intel Motherboard - Intel Motherboards -- has a RAID controller on it (isn't this pretty standard nowadays?), so I won't have to purchase a separate RAID controller card. If I am under the wrong impression here, however, please let me know!

Steve

[Harm Millaard]

Steve,

The chipset on the mobo is the ICH9R, which supports Raid 0, 1, 5 and 10. Raid 10 is way too costly to my taste and not very fast. Raid 5 is supported. However, the more attractive raid formats, like raid 3, 6 or 50 are not supported. There is no BBM or cache capability and the raid implementation is pretty backward in comparison to dedicated hardware cards. But you get what you pay for, which is nil in this case. Hard to beat.

[Steven Reid]

Originally Posted by Harm Millaard

Steve,

The chipset on the mobo is the ICH9R, which supports Raid 0, 1, 5 and 10. Raid 10 is way too costly to my taste and not very fast. Raid 5 is supported. However, the more attractive raid formats, like raid 3, 6 or 50 are not supported. There is no BBM or cache capability and the raid implementation is pretty backward in comparison to dedicated hardware cards. But you get what you pay for, which is nil in this case. Hard to beat.

Well, Harm, you sound quite critical of MOBO Raid controllers, at least for this MOBO. ;) Is this analogous to gripes about on-board sound (i.e., it is just OK, but better to get dedicated sound card)?

Is just OK enough for video editing? If not, I looked into dedicated cards. Wow -- I see a great variance in price and features of RAID controller cards. Narrowing down to those that (1) are Vista 64-bit compliant (the OS I intend to use), (2) have at least four (4) internal SATA ports, and (3) have good to great reviews, I found the following inexpensive card: Newegg.com - Rosewill Silicon Image RC-209-EX PCI External e-SATA x2/ Internal SATA x4 1.5G HDD Controller Card Supports RAID0/1/5/0+1/ or un-RAID modes - Controllers / RAID Cards

So, is this $20 card going to blow away the RAID capabilities of the MOBO I listed above? Even if there are modest improvements, it seems that they might be worth $20. In addition, I would not use up SATA ports on the MOBO, leaving room for future additions of HDDs. Is this a fair assessment, or am I looking at the wrong considerations?

Steve

[Harm Millaard]

Steve,

The on-board ICH9R is decent in comparison to dedicated cards and maybe even better than the $ 19 card from Newegg you linked to.

In terms of performance there are 3 levels, on-board, which gives the most basic performance, software assisted cards, which use the CPU to assist in performing the necessary calculations like Promise, Highpoint and SIIG and the third are the hardware controllers like 3Ware and Areca, which offer the most extensive range of raid options and the best performance, because all required parity calculations are off loaded from the CPU to the controller. In addition, these controllers offer BBM (battery backup modules) and expandable cache memory. They can often be found with 8, 12, 16 or even 24 ports. Areca is the absolute top performer in this area, especially with the IOP-348 chipset.

Your choices would logically limit themselves to either using the on-board controller (free) and if that does not give you the performance you need, than have a look at an Areca 1680iX card, but it is expensive. I would forget about Promise, Highpoint or SIIG as an intermediate step. IMO that is a waste of money.

Raid3, 6, 50 and even more esoteric forms like 7 or 30 can only be had with the hardware assisted controllers. If you don't need that, why not use the on-board chip?

[Steven Reid]

Originally Posted by Harm Millaard

Steve,

The on-board ICH9R is decent in comparison to dedicated cards and maybe even better than the $ 19 card from Newegg you linked to.

In terms of performance there are 3 levels, on-board, which gives the most basic performance, software assisted cards, which use the CPU to assist in performing the necessary calculations like Promise, Highpoint and SIIG and the third are the hardware controllers like 3Ware and Areca, which offer the most extensive range of raid options and the best performance, because all required parity calculations are off loaded from the CPU to the controller. In addition, these controllers offer BBM (battery backup modules) and expandable cache memory. They can often be found with 8, 12, 16 or even 24 ports. Areca is the absolute top performer in this area, especially with the IOP-348 chipset.

Your choices would logically limit themselves to either using the on-board controller (free) and if that does not give you the performance you need, than have a look at an Areca 1680iX card, but it is expensive. I would forget about Promise, Highpoint or SIIG as an intermediate step. IMO that is a waste of money.

Raid3, 6, 50 and even more esoteric forms like 7 or 30 can only be had with the hardware assisted controllers. If you don't need that, why not use the on-board chip?

Harm, I"m grateful for the tutorial. It meets me at my level of relative inexperience, as I'm sure you can tell. With these considerations in mind, and my hobbyist-only interest, I think the on board RAID would suit me just fine.

Steve