Hardware RAID in new Mac Pro - yes/no?

[funkahdafi]

Hi,

I am currently using a 2006 Mac Pro with a 2 TB software RAID-0 array (two drives) and two additional drives without RAID. I am using one of the additional drives as my TimeMachine drive.

I used RAID 0 simply to have higher performance.

Now I am going to order the new Mac Pro this week and I was wondering to put in the RAID card or not. How much of a performance gain can I expect from the hardware RAID vs. software RAID? Other advantages other than that?

I am also wondering if I should expand from RAID 0 to RAID 0+1 to gain redundancy in addition to performance. However, I would have to deploy 4 drives and thus would lose my TimeMachine drive. I am also not sure if this setup would support Bootcamp.

What are your thoughts? Is it worth upgrading from software to hardware RAID? And if so, is the Apple RAID card a good choice (I know I will have to wait 4-5 weeks longer for delivery of my new baby)?

Thanks

 

[Abulia]

I am currently using a 2006 Mac Pro with a 2 TB software RAID-0 array (two drives) and two additional drives without RAID. I am using one of the additional drives as my TimeMachine drive.

I used RAID 0 simply to have higher performance.

I do pretty much the exact same thing on my current Mac Pro as well.

Now I am going to order the new Mac Pro this week and I was wondering to put in the RAID card or not. How much of a performance gain can I expect from the hardware RAID vs. software RAID?

Little to none. Software RAID at this point has little overhead or performance cost.

Other advantages other than that?

The RAID card lets you use other RAID options -- such as RAID 5 -- that are unavailable via software.
It has a battery on the card to complete any data transactions, thus safeguarding your data. External connectors for adding external RAID arrays.

And, obviously, the card handles all RAID operation for better performance. Now the question is whether that performance is so much better than software RAID (unless you need something like RAID 5) to justify the price.

I am also wondering if I should expand from RAID 0 to RAID 0+1 to gain redundancy in addition to performance. However, I would have to deploy 4 drives and thus would lose my TimeMachine drive.

This depends on your level of acceptable risk. Don't confuse fault tolerance with backup or recovery. RAID 0+1 or 1+0 is meant to maximize uptime against disk failure. Time Machine is more for user failure.

Does anything else on your network use TM or just the Mac Pro? You could create a volume on your RAID 1+0 array and point TM to that. TM does not have to be its own physical disk, IIRC.

I am also not sure if this setup would support Bootcamp.

No, it would not.

What are your thoughts? Is it worth upgrading from software to hardware RAID? And if so, is the Apple RAID card a good choice (I know I will have to wait 4-5 weeks longer for delivery of my new baby)?

I would need to know more about what you use the machine for. Do you use this machine to make money? What is your time worth in the event of downtime? If you lose a disk will you lose business? These are the kinds of decisions that should factor into not only if you should get a RAID card but what your fault tolerance and data recovery strategy should be.

Since you didn't share this information I'm going to just guess that you're a hobbyist and this is entirely for your own use. I'd do software RAID 0 for performance and keep your TM disk. It doesn't sound like the card would do anything for you.

And don't forget Snow Leopard coming and ZFS.

 

[funkahdafi]

Thanks Abulia.

Actually I use my machine to make money, so data safety is very important for me. That's why I don't want to lose my TimeMachine.

The main reason why I am looking at the RAID card is to gain performance. I know RAID is not backup, it just gives you the option to be back up quicker, in case only one drive fails. That's why I would *highly* welcome RAID 10, but only of the price-performance ratio justifies this. If there is little to no performance gain when using the RAID card, then I don't think I want to spend the money on it and wait 6 weeks before Apple can deliver this.

How much of a performance gain will ZFS introduce?

Does the Apple RAID card also allow for external connections?

 

[funkahdafi]

One more question:

Would striping four drives give me higher performance than striping two drives? Can this be done with software raid (without destroying the current raid set)?

 

[Tesselator]

One more question:

Would striping four drives give me higher performance than striping two drives? Can this be done with software raid (without destroying the current raid set)?

More proformance? Yes! Something like this:

2 drives = 190% Speed Increase.
3 drives = 270% Speed Increase.
4 Drives = 340% Speed Increase


Without destroying the set? No, Not that I know of. You'll have to reformat.