Computer storage has always been the slowest component in the chain. Your processor has a fast cache that is much slower (but still fast!) Interacts with RAM, and then we have system drives that are orders of magnitude slower again.
RAID, or Redundant Array of Independent / Low Cost Disks , is a method of combining multiple drives into one to improve performance, reliability, or both. Since SSDs are quickly replacing mechanical hard drives, this gives us a choice: RAID Raid vs. SSD Raid. There is no absolute winner here, so let’s take a close look at it.
Summary of RAID Levels
Although there is no universal standard for RAID configurations, there are several so-called â€œlevelsâ€ of RAID that have become fairly commonplace. When we compare HDD RAID technology with SSD RAID technology, it is important to remember the pros, cons, and the number of drives required for each type of RAID setup. Let’s take a quick look at them in a nutshell:
- RAID 0 requires two disks, does not provide redundancy, but provides greater speed and no wasted disk space.
- RAID 1 requires two drives, provides redundancy, but only a small improvement in speed and 50% disk space.
- RAID 10 requires four drives, provides redundancy, provides faster reads, better write speeds, and sacrifices 50% of the disk space.
- Most users will not benefit from increasing SSD RAID speed.
- HDD RAID is still the best choice for data storage.
- SSDs are robust enough to make RAID useful only for mission-critical applications.
Of course, there are other, more complex RAID levels (such as 1E, 5, 50, 6, and 60), but these three are the most common ones that might interest regular users.
HDD RAID vs. Single SSD
We believe that the most common reason someone might wonder about RAID and how it relates to SSDs comes from this particular comparison. So we’ll get rid of that first.
Mechanical hard drives are quite slow, so one popular way to improve throughput is to combine two identical drives in a RAID 0 configuration. Data is spread across both drives, and they act like one hard drive, but with (theoretically) twice the transfer rate. Since each drive has a unique piece of your data, you can always use both drives to perform any operation.
Unfortunately, when it comes to sheer speed, a single SSD always outperforms a RAID 0 hard drive. Even the fastest and most expensive 10,000 RPM SATA III consumer hard drive delivers only 200 MB / s. In theory . Thus, two of them in RAID0 will cope only a little less than half.
In other words, if you’re looking for raw performance, one SSD will always be better than a pair of mechanical drives. Even if they are the fastest mechanical drives in the world.
The same goes for reliability and data protection. If you have a RAID 10 configuration with four hard drives, you still get double the speed of the drive and can lose a drive without losing data. Regardless, a single SSD will still be a more reliable solution. SSDs have a limited number of writes before they can no longer overwrite existing data, but you can still read all of the data on the drive.
A spontaneous SSD failure is incredibly rare, but you always have the option of running two SSDs in a RAID 1 array. There is no significant speed gain, but one drive can fail completely without losing data. We do not recommend spending money on installing a RAID 1 SSD purely for data security reasons. It is much more beneficial to simply back up the hard disk image to an accessible external drive or to the cloud, since most desktops are not mission-critical.
Now that we’ve covered a single SSD scenario, let’s talk about a direct RAID-to-RAID comparison. That is, mechanical disks in RAID versus SSDs in RAID There are three main aspects to consider: performance, cost, and data reliability. Let’s take a closer look at each of them.
You probably won’t be surprised to learn that an SSD RAID configuration always outperforms any mechanical disk RAID configuration in sheer performance. The real question is how much performance you get from using SSDs in RAID mode and is it worth it. It’s a difficult question.
One factor is hardware RAID versus software RAID A dedicated hardware RAID controller will provide better performance than a software solution. Also, as the speed increases, other components of your computer can become a limiting factor or bottleneck.
For example, in day to day use, the difference between a SATA III SSD and an M.2 NVMe PCIe drive is small. even though the latter is five or six times faster. Games don’t load noticeably faster, and apps don’t necessarily run faster. On the other hand, workloads such as video editing or professional applications that do bulk analysis of a dataset consume as much bandwidth as you can offer.
This means that placing two SSDs in a RAID 0 array probably won’t improve the experience for the average user, and the cost could be better spent elsewhere on the system
Although solid state drives have dropped in price dramatically over the past few years, they are still many times more expensive per gigabyte than mechanical drives. In fact, mechanical drives have been increasing in capacity lately as they cannot compete in performance.
This makes solid-state drives unattractive as backup drives. Mechanical drives in purely redundant or redundant RAID configurations are still very relevant and cost effective for desktop users. If you are using a home NAS (Network Attached Storage) system for streaming or file sharing, this is the most practical choice.
If you absolutely need the speed of two SSDs in a RAID 0 array, or if you have a mission-critical drive that takes advantage of RAID 1, you are looking at twice the price of a single drive. Only you can decide if 200% of the cost is worth the benefits of any option.
Reliability and endurance
SSD reliability is something we’ve written about before, and it’s a tricky comparison to mechanical drives. SSDs wear out when too much is written on them. However, for modern discs, the record longevity is far beyond what most users will ever need.
Complete loss of data, even if the SSD cannot be written to, is very unlikely. In many ways, RAID exists because mechanical drives are prone to failure in the first place. Solid state drives are so reliable that they don’t make redundant RAID unnecessary.
No clear answers
By having a clear understanding of where each approach works best, you should have a much better idea of ??which option is most functional and cost effective for you.