2TB SATA SSD vs 2x1TB SSD in RAID0?

[camner]

I have a 4-bay Thunderbolt enclosure and I currently only use 2 of the bays.

For my new 27" iMac 2020 I need 2TB of external storage. The price difference between a single 2TB SSD and 2x1TB SSDs is pretty small.

I have a couple of 512TB Samsung 860EVOs and I tested i/o speeds using Black Magic Disk Speed Test. A single Samsung EVO was giving me write speeds of about 650MB/s, but when I created a RAID0 array with both the 860s, I got almost 900MB/s, which is a pretty decent increase.

I've read that higher capacity SSDs are quicker (because of the # of simultaneous writes they can do), so I was wondering whether it would be better to get a single 2TB SSD vs creating a RAID0 array out of two 1TB SSDs.

 

[Juicy Box]

What are you going to be using the storage for?

I've read that higher capacity SSDs are quicker (because of the # of simultaneous writes they can do), so I was wondering whether it would be better to get a single 2TB SSD vs creating a RAID0 array out of two 1TB SSDs.

Any speed advantage of the larger, single storage option would not compare to the speed advantage of the striping RAID0.

Just make sure you have a reliable back up (for any type of storage).

If speed is the goal, you could probably do just as well with a TB3 SSD or even a USB3.2 Gen 2x1 SSD drive.

I got almost 900MB/s

I am on a Late 2012 iMac with TB1 ports, and for my boot drive I am using a TB3 Samsung X5 enclosure with an upgraded 970 EVO Plus NVMe and get the same speeds. The speeds would be much quicker on your newer Mac.

Although, it isn't cheap as getting two SATA SSDs.

 

[camner]

What are you going to be using the storage for?

• ~500GB of photos & videos that are managed by Lightroom
• Videos edited in iMovie (rarely over 500MB for a single video) are exported to this drive
• ~100GB of music
• ~400GB of miscellany, including some larger videos that are infrequently accessed and many small documents also infrequently accessed

 

[ght56]

I agree shopping against some of the newer USB 3.2 gen 2 SSDs is worth checking out. Some of these are pretty cheap and they are doing read and writes around 1,000 MB/s, plus you would be getting a potential reliability benefit over RAID 0. The Samsung T7 is an example of one of these.

That said, there is another alternative that would provide more expansion potential in the future. You could get yourself one of the relatively inexpensive USB 3.2 gen 2 (10 Gbps) NVMe enclosures and a 2TB m.2 NVMe SSD. You'll saturate the 10 Gbps USB 3.2 offers (so likely real-world sustained of around 1,000 MB/s), but, should you want more speed down the line, just purchase a Thunderbolt 3-m.2 NVMe enclosure and you could be looking at sustained reads and writes more on the order of 3,000 MB/s.

 

[camner]

I agree shopping against some of the newer USB 3.2 gen 2 SSDs is worth checking out. Some of these are pretty cheap and they are doing read and writes around 1,000 MB/s, plus you would be getting a potential reliability benefit over RAID 0. The Samsung T7 is an example of one of these.

That said, there is another alternative that would provide more expansion potential in the future. You could get yourself one of the relatively inexpensive USB 3.2 gen 2 (10 Gbps) NVMe enclosures and a 2TB m.2 NVMe SSD. You'll saturate the 10 Gbps USB 3.2 offers (so likely real-world sustained of around 1,000 MB/s), but, should you want more speed down the line, just purchase a Thunderbolt 3-m.2 NVMe enclosure and you could be looking at sustained reads and writes more on the order of 3,000 MB/s.

Thanks for this suggestion. Any recommendations on NVMe SSDs? The ones that are typically mentioned as "best" are pretty pricey and probably beyond what I need for my use case. I'm more interested in reliability and longevity than I am in getter the highest possible speeds (which I wouldn't get anyway in a USB 3.2 Gen 2 case).

 

[ght56]

I'm using a Samsung 970 Evo Plus. They are definitely a bit pricier than SATA. If reliability is the top concern, I would personally shy away from RAID 0 and lean toward either a single 2 TB SATA drive or a standalone USB 3.2 Gen 2 external.

 

[justashooter]

You didn't say what 4 bay Thunderbolt enclosure you have (Thunderbolt 1 or 2?), but using the enclosure you already have, the easiest way to go is 2 1TB ssd's in a software RAID 0 and then also install a 2 or 3 TB hard drive as a single drive to back up the SSD drives to.

 

[camner]

You didn't say what 4 bay Thunderbolt enclosure you have (Thunderbolt 1 or 2?), but using the enclosure you already have, the easiest way to go is 2 1TB ssd's in a software RAID 0 and then also install a 2 or 3 TB hard drive as a single drive to back up the SSD drives to.

Sorry...the enclosure is a Thunderbolt 3 enclosure. The two HDDs I have in it right now are backup drives. One is a Time Machine backup volume, and the other backs up both my internal system drive and the (too small) single SSD I have in the enclosure. I'm looking to replace that single SSD either with a larger, 2TB single SSD or two 1TB SSDs configured as a striped RAID0 array.
[automerge]1600984404[/automerge]

I'm using a Samsung 970 Evo Plus. They are definitely a bit pricier than SATA. If reliability is the top concern, I would personally shy away from RAID 0 and lean toward either a single 2 TB SATA drive or a standalone USB 3.2 Gen 2 external.

Are RAID0 arrays inherently less reliable than a single SSD? If so, why is that?

 

[StellarVixen]

RAID0 has no redundancy. RAID0 treats all your disks as one, therefore it strips data across all disks. If one drive fails, all your data is gone. So you need another 2TB drive for backup.

Even RAID Assistant states it clearly:

I’d say one single 2TB drive is better overall.

 

[camner]

RAID0 has no redundancy.

That's why I have two HDDs in the enclosure: one for Time Machine hourly backups and one for daily full clones (I also do weekly backups that I keep for a month on a rotating basis). Given my needs, I'm pretty happy with my backup strategy; I don't think I need the level of protection that higher level RAID arrays give. I was only considering a RAID0 at all because I can get an almost 50% increase in i/o speeds over a single SSD.

I’d say one single 2TB drive is better overall.

I still don't understand the rationale for this, but I'm likely missing something.

 

[justashooter]

My advice still stands even though the configuratioin is slightly different and that you perform regular backups, which from your other posts you do. Use 2 1tb SSD's as a RAID 0 for your working drive for video editing, photo editing, etc, you will get your 900MB/s, and back up the RAID to a hard drive. I've been doing this for some time, using two external USB3 enclosures with SSDs and making them software RAID 0 for video work. On my older 2012 system I'm only getting 600MB/s but it makes a difference when video editing. Been looking at thunderbolt enclosures just haven't pulled the trigger yet.

 

[ght56]

Are RAID0 arrays inherently less reliable than a single SSD? If so, why is that?

Yes, because the loss of one drive usually means all data is lost, as individual files are generally split across the drives. By having two drives, you now have two that can potentially fail instead of one, introducing more variables into the mix. If you are backing it up, it's not as big of a deal, but if you are prioritizing reliability over speed, a single drive makes sense to me.

Further, your usage may also mean that a single disk is even more desirable if you are going to be using this SSD setup when exporting unique files. Obviously, the HDD that you are backing the SSD up to cannot keep up with the SSD in real time. If you are exporting unique data to your external SSD (i.e., you are not saving to the local disk), there is going to be a time period where that data is not backed up elsewhere until the backup on the HDD can catch up. Should either of the two RAID0 SSD drives fail during this intermediate period, the data is likely gone. A single SSD would reduce the chance of this happening, even though it is arguably pretty small if we are talking about established SSDs such as those from Samsung or Micron, for example.