What is SSHD (Solid State Hybrid Drive)?

A New Marketing Name for a Hybrid Storage Drive

Seagate Laptop SSHD 1TB Solid State Hybrid Drive 6GB/s 2.5" - Internal Drive Retail Kit (STBD1000400)
Seagate Technology PLC

If you have been looking at upgrading your hard drive for a laptop or desktop computer in the past few months, you may have come across the term SSHD. What is this in relation to hard drives and solid state drives? In fact, this is a new marketing term that was coined by Seagate to essentially label what had previously been referred to as hybrid hard drives. The drives are a blending of the traditional hard drive and the new solid state drive technologies. The problem is that this is leading to confusion in the market as buyers might be mistaking these for full solid state drives (referred to as SSDs).

What is the Benefit of the SSHD?

The tagline from Seagate for their new SSHD lineup is "SSD Performance. HDD Capacity. Affordable Price". Essentially they are trying to say that these new drives will offer all the benefits of the two technologies without any real significant costs increases. If this was true, wouldn't all computer systems be using an SSHD instead of a traditional hard drive or a solid state drive?

The fact is that what these drives are is, in essence, a traditional hard drive with a small capacity solid state drive added to the drive's controller to act as a sort of cache for frequently used files. It is not all that different from taking a standard hard drive to be the primary storage of a computer system and then adding a small solid state drive as a cache through a system like Intel's Smart Response Technology.

Let's look at the claim of capacity first as this is the easiest to see. Since an SSHD is essentially the same as a traditional hard drive but with some of the space inside of the drive to hold the solid state cache, it is no surprise that the SSHD have roughly the same capacity as traditional hard drives. In fact, the laptop and desktop variants of these drives have the exact same capacities. So this claim is entirely true.

Next, we compare the prices of the SSHD to the other two. In terms of capacity ratings, the SSHD does cost slightly more than a traditional hard drive. This is the result of adding in the extra solid state cache memory and additional firmware to control the caching processor. This ranges from about 10 to 20 percent more than a traditional hard drive. On the other hand, the SSHD is far cheaper than a straight solid state drive. For the capacities, an SSD will cost anywhere from five to about twenty times the cost of an SSHD. The reason for this wide price disparity is that the higher capacity solid state drives require much more expensive NAND memory chips.

So Is the Performance Like An SSD?

The real test of a solid state hybrid drive is how the performance will be compared to traditional hard drives and solid-state drives. Of course, the performance is highly dependent upon how a computer system is used. The real limiting factor of an SSHD is the amount of solid state memory that is used for the cache. Right now, it is a very small 8GB that is used. This is an extremely small amount that can be filled up quickly requiring frequently purging of the cached data. As a result, the people who will see the greatest benefit from these drives is those who use their computer with a limited number of applications. For instance, a person that uses their PC just to browse the web, do email and maybe some productivity applications. Someone who is playing a wide variety of PC games is not going to see the same benefits as it takes multiple uses of the same files for the caching system to determine which files to put in the cache. If they aren't used repeatedly, there is no real benefit.

Boot times are an excellent example of how things can be improved with a standard system maybe going from around twenty seconds on a hard drive to as low as ten with an SSHD. This still isn't quite as quick as a solid state drive that can achieve under ten seconds. Go beyond just booting up the computer and things will definitely be much murkier. For instance, if you are copying a large amount of data (for instance using it to back up another drive), the cache will quickly be overloaded and the drive will essentially perform the same level as a normal hard drive but likely less than a high-performance hard drive model.

So Who Should Consider Getting an SSHD?

The primary market for a solid state hybrid drive is with laptops. The reason is that the limited space on these systems generally prevents more than a single drive from being installed within them. A solid state drive may provide lots of performance but limit the amount of data that can be stored on it. On the other hand, a hard drive has lots of space but doesn't perform as well. An SSHD can offer an easy and affordable way to offer high capacity but slightly improved performance for anyone that might want to upgrade an existing laptop system or compromise between the two extremes in a brand new system.

While there are desktop SSHD now available, we generally would not recommend them. The reason is that desktop systems including many small and slim designs have the space to hold multiple drives. For these systems, a combination of a small solid state drive with a traditional hard drive would likely offer better performance and not cost that much more than purchasing a SSHD. This is especially true for any system that has the ability to use the Intel Smart Response Technology. The only exception here is those mini desktop PCs that only have the space to fit a single mobile size drive. They may benefit the same as a laptop would.