How many Storage devices can I put in a raid 0 configuration?

[Logankilby]

Theoretically, Is there a limit to how many drives I can put into a raid 0 zero configuration with an ssd cache? Is there a limit or can I have an infinite amount of hard drives?

[Unstoppablechicken]

I am also interested to know about this I feel raid 0 is severely underutilized for game library disks as not everyone can afford ssds for this application. 

[Darkimane]

in theory, assuming you can store, power etc all the drives and you have enough space on your controller/controllers it is limitless however with raid 0 being non-redundant you wouldn't want to put too many drives as it vastly increases your chance of a failure 

[Unstoppablechicken]

Uh fair but what about raid 5?

[Eigenvektor]

5 minutes ago, Unstoppablechicken said:

Uh fair but what about raid 5?

Same thing. Unlimited in theory, limited by how many drive you can fit inside your PC.

[shoutingsteve]

Well... as it is controlled by the controller (I know that sounds ridiculous) it would be absolutely up to the controller.  But, Raid 0 has diminishing returns as there still has to be a controller to sort out what data comes from where.  Two drives does not perform at 200% the speed of a single drive. and with three drives, you will be lucky to get 250% the speed of a single drive.  There would be no difference (except reliability) between 6 ad 7 drives.

[shoutingsteve]

1 minute ago, Eigenvektor said:

Same thing. Unlimited in theory, limited by how many drive you can fit inside your PC.

RAID 5 is where it's at.  I don't know why it isn't the standard for upper level consumers.

[Unstoppablechicken]

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[Dedayog]

7 minutes ago, shoutingsteve said:

Well... as it is controlled by the controller (I know that sounds ridiculous) it would be absolutely up to the controller.  But, Raid 0 has diminishing returns as there still has to be a controller to sort out what data comes from where.  Two drives does not perform at 200% the speed of a single drive. and with three drives, you will be lucky to get 250% the speed of a single drive.  There would be no difference (except reliability) between 6 ad 7 drives.

Realistically, it's much lower.  I use Raid O for my 2 860 Evo's and in real world gaming I see a 25-30% faster load time vs just a single 860 in long load time games (heavily modded games where load times are in minutes rather than seconds).

 

Would I do it again?  Sure, but is it really worth it?  Depends on the user and use-case.

[xentropa]

Theoretically infinite depending on the controller but there are diminishing returns due to the computational overhead of striping data across devices.

 

Raid imo is only worth it for QLC nand.  SLC should be fast enough already in that SATA controller is the bottleneck.

[Eigenvektor]

4 minutes ago, Dedayog said:

Realistically, it's much lower.  I use Raid O for my 2 860 Evo's and in real world gaming I see a 25-30% faster load time vs just a single 860 in long load time games (heavily modded games where load times are in minutes rather than seconds).

 

Would I do it again?  Sure, but is it really worth it?  Depends on the user and use-case.

That's because you're using drives that are very fast already, very close to the limits of throughput on the controler and/or bus.

 

Load times don't necessarily scale linearly wirh drive speed and may be limited by CPU and/or memory speed, e.g. if data needs to be decompressed. So a better test would probably be copying files to/from other fast storage.

[Dedayog]

25 minutes ago, Eigenvektor said:

That's because you're using drives that are very fast already, very close to the limits of throughput on the controler and/or bus.

 

Load times don't necessarily scale linearly wirh drive speed and may be limited by CPU and/or memory speed, e.g. if data needs to be decompressed. So a better test would probably be copying files to/from other fast storage.

Right, that's why i outlined my use-case and added it depends on that.  

 

For file transfers Raid 0 is very nice, but it's a very limited set of folks who will truly benefit from that.

 

 

[Jarsky]

23 hours ago, Logankilby said:

Theoretically, Is there a limit to how many drives I can put into a raid 0 zero configuration with an ssd cache? Is there a limit or can I have an infinite amount of hard drives?

Theoretically the limit is 65535 devices in a single configuration. 

Practically, most high end hardware controllers have a limit of around 250 drives per controller with the help of expander cards / backplanes. 

 

So say you had 4 x LSI 9305-16e's, each feeding a Storinator 60XL enclosure full of disks per port.

That system along with 16 x Storinator enclosures, would have a total of 960 drives. That would take up 2 full height server cabinets. 

 

Once you get into SAN's with fiber switched storage, then its a whole different game. 

 

[Nick7]

Generally, RAID cards will usually have limit of upto 16 drives per RAID array.

Larger pools are usually a mix - RAID5 on let's say 8 drives, and than stripe or simple spanning on top of that. Also, larger pools (like storage arrays) use those RAID5's (or RAID6, or RAID1) to create logical pool, and than extents are used to create LUN.

 

As it's said, it is possible with SW solutions to go beyond 16 drives, but even with RAID0 you will get diminishing returns.

[Blue4130]

On 9/9/2020 at 12:42 PM, shoutingsteve said:

RAID 5 is where it's at.  I don't know why it isn't the standard for upper level consumers.

It's reliability is less with drives getting larger in size. If one drive fails, you are vulnerable during the rebuild. And with something like 4tb or larger, rebuilds can take major time. During this time, all of the disks are working hard, just the sort of activity that promotes HDD failure. It's been sidelined by more efficient and safe redundant solutions like raid6, zfs and raid10. 

[Nick7]

7 hours ago, Blue4130 said:

It's reliability is less with drives getting larger in size. If one drive fails, you are vulnerable during the rebuild. And with something like 4tb or larger, rebuilds can take major time. During this time, all of the disks are working hard, just the sort of activity that promotes HDD failure. It's been sidelined by more efficient and safe redundant solutions like raid6, zfs and raid10. 

Yes, with larger drives you are better off with RAID6. That's what nowdays is most commonly used in storage systems when using HDD's.

However, for home use, RAID5 is generally more than adequate, unless you are using like 10+ drives.

ZFS is NOT RAID. ZFS uses RAID to achieve redundancy.

RAID10 is much less safe than RAID6. In RAID10 when one drive dies, you are fine.. however, if another one dies which was mirror of first one - you're screwed. RAID6 can tolerate failure of any 2 drives simultaneously.

Only advantage of RAID10 is faster rebuild, but this also depends on amount of drives, etc.. (RAID10 will have fastest rebuild times, but depending on number of drives, load, etc... RAID5/6 can be almost as fast).