Software RAID, hardware RAID or NAS device – what to choose for a home user

Everyone who gets enthusiastic about building his or her own array starts with choosing a fitting implementation. Should one select a software or hardware RAID, or a ready-made NAS device? This article attempts to discuss the main pros and cons of each option. And yes, we are going to consider these devices from the home user's point of view, as the enterprises traditionally prefer a hardware RAID where fault tolerance and high performance of hard drives are a must, not a luxury.

Typically, in a RAID array two or more hard drives are combined into a single storage to increase performance and provide a certain level of system fault tolerance.

Software RAID vs hardware RAID

Price

Software RAID – requires a minimal set of hard drives and an operating system which has the RAID capability. For example, Windows allows a single drive to be split into 2 partitions and make them RAID1 or RAID0. If you still want to do something really similar to a regular hardware RAID, use multiple drives combined into a single storage.

Hardware RAID – requires a hardware controller which is an additional component that you have to pay for. The price of a RAID controller in 2020 starts at $100 USD. As for the drives, often the manufacturers of controllers advise to purchase certain drive models and therefore you cannot just take disks at hand and combine them into a RAID storage in a way you do in a software RAID. So, with a hardware RAID you most likely will have to spend money on new (compatible) drives.

NAS devices – are essentially the same RAID inside, but access to data is provided through the network. That is, you don't have to rebuild your PC, connect a bunch of wires to the drives, consider component compatibility and so on. All you have to do is to purchase a nice box, insert the drives, perform a simple setup and get access to the data stored on your NAS from any device you and your family own. Of course, such devices are pricey compared to a minimal hardware array. In addition to the drives, you also need to buy a NAS box. For example, a 2-drive NAS box costs you a minimum of $250 USD.

Performance

Software RAID – suffice it to say that the whole load of placing data on the drives, calculating checksums, etc. falls on the computer's CPU, which naturally does not increase the performance of the system.

Hardware RAID – In case of a hardware RAID, you get a significant performance boost because the controller frees the CPU from the basic RAID operations. Generally, the more complex the RAID layout, the more noticeable the effectiveness of the standalone controller. Also, modern controllers feature a buffer memory ("cache") that stores the last few blocks of data, which, when frequently accessed by the same files, can significantly increase the performance of the disk system.

NAS device – it should be noted at once that you shouldn't expect comparable performance. As there is such a component as a network, the overall performance is always lower as compared to the hardware RAID, which is connected to the computer almost directly.

Reliability

Software RAID – software implementation of a RAID array offers almost no service capabilities. All operations of replacing a failed drive, adding a new drive, changing the RAID level, etc. are often resulted in data loss not to mention the fact that during these operations the system will be completely busy and no regular work is possible

Hardware RAID – high reliability. However, unlike a NAS, there is no on-the-fly drive replacement in regular RAID controllers. That is, if a drive fails, you should shut down the whole system, replace the drive, and perform a complete RAID rebuild. Nevertheless, this is mostly not a matter of reliability, but rather of usability.

NAS device – as with the hardware RAID, reliability is largely determined by the RAID level used. Most NAS devices are hot-swappable, thus ensuring smooth user experience.

SUMMARY: If you want to play around with a RAID, and you don't have much experience with hardware, and you don't have extra money, then choose a software RAID but don't expect much it will make your life more enjoyable. In other circumstances, choose either a hardware RAID or a NAS device, which are the best choice for storing personal data.