• 10/28/2015
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SSD Pricing Vs. HDD Costs

Any way you cut it, solid-state drives are becoming a better bargain than hard disk drives.

In some ways, the solid-state drive/flash market is a clear example of irrational behavior. We have a product that supercharges systems and reduces overall costs by large factors, but buying that product often seems to hinge on the price of the device itself.

Combined with this is the marketing hype intended to create a class of “enterprise SSD” that separates commodity SSDs from the “more sophisticated” enterprise-class units. As a result, there's a tiered pricing scheme, but the demarcations are blurred, unlike the tiering of hard disk drives that we’ve known for years.

Can we use cheap SSD in the enterprise? This is a bit like asking if we can use cheap HDD. The answer is, “Of course!” However, there is a caveat: . That cheap SSD has to have battery hold-up power built-in to save unwritten data blocks in the event of a system power failure, but this is normal for any decent solid-state drive.

The difference between SSDs and HDDs is simply performance. We are talking 5x performance for sequential operations and as much as 50x for random. In other words, if performance is your metric, one SSD is worth perhaps 20 HDDs. (Hint: SSD wins that price comparison handily!)

Studies have shown that while SSDs are more expensive than HDDs on a price-per-terabyte basis, the fact that the minimum size of an HDD is reaching 1 TB means that systems such as PCs and embedded systems that don’t need a terabyte can use a cheaper SSD (with just the needed capacity). This undercuts a large swath of the HDD market in desktops and other low-cost, low-performance gear.

The idea of using smaller SSDs may also work really well with microservers, which typically don’t need much storage on each microserver module.  This would boost response time and performance and also reduce power needs.

Now that we’ve disposed of a huge part of the HDD market with this “right-sized SSD” approach, let’s look at the thornier issue of servers. Most of the servers sold today end up in clouds or virtual clusters. With high VM counts and Docker containers increasing the instances per server by as much as 3x or 4x, we have an IO starvation problem that SSDs can fix. Putting in an SSD is cheaper than adding three more HDDs.

Still, there are IT purists who still use price-per-megabyte as the metric for storage drive decisions. Let’s look at the nose-to-nose pricing for SSDs versus HDDs and see where the game sits. First though, I must mention the classic FUD on this issue, which is to measure a solid-state drive against that $30 terabyte bulk drive. This is comparing a racehorse to a snail! Often, too, people make comparisons between an “enterprise” SSD such as a PCIe unit and cheap bulk HDD. That’s misleading, since PCIe drives are in a totally different class of performance to regular SSD, and are very expensive as a result.

A fairer comparison is to look at mid-tier SSDs against 10K RPM HDD, the fastest HDD now on sale. On a capacity basis, we have SSDs up to a couple of terabytes in the mainstream. Compared to the  10K RPM HDD of the same capacity, the SSD is cheaper.

SSD is still roughly 4x the price when comparing against bulk 1 TB HDD. Power savings and better reliability close the gap quite a bit, but SSDs are still more expensive than cheap bulk HDDs. Even here, however, the issue is a bit of a red herring. With SSDs' extra performance making compression and deduplication possible, we need fewer drives of any type and are more focused on latency of data delivery. Here, the SSD is a very clear winner.

Figure 1:

(Image: YuriyVlasenko/iStockPhoto)

While there will continue to be arguments about SSD versus HDD pricing, SSD is close to winning the market. Further price erosion and capacity improvements to be expected in 2016 and 2017 will close any remaining gap to the point that we will focus on the performance and reliability benefits of SSD, rather than price and capacity questions.

Meanwhile, all-flash arrays are decimating high-end HDD appliance sales in a market segment that really does understand the cost/performance issue.

What else is happening in the near and longer term that impacts the SSD/HDD pricing debate? 3D NAND production is mainstream, lowering drive costs and increasing capacities. We are seeing SSDs that exceed HDDs' capacity “wall” at 10 TB by going up to 16 TB. SanDisk has introduced a line of SSDs aimed at the desktop and the IoT markets with pricing per drive lower than the cheapest hard drive.

On the negative side, Western Digital has purchased SanDisk, which may reduce competition and delay SSD price drops in the next few quarters. Intel is investing $5.5 billion in new fab capacity in China, though some of this may target its 3D XPoint memory technology, which may impact sales of high-end SSD. This new technology could disrupt the flash industry and delay price drops somewhat. However, in the longer term, both WD and Intel will be bumps in the road for SSDs and their ascendance over hard drives.


SSD wins

I've been saying to everyone I know for years, if you want to upgrade your home, work or server system, switch out the HDD for an SSD, even if it's only on the boot drive. It is hands down the biggest upgrade to revolutionise your PC that you can make and could have made for the past 5+ years. 

The near-isntant booting, the snappy feel to the entire ecoysystem, it's unparalleled on HDD equipped systems. 

Plus, considering the 3DNAND being touted by Intel and Micron now and we could really push past that storage capacity advantage that HDDs have, while improving performance by even more of a magnitude.

Re: SSD wins

@Whoopty     I agree. At least use SSD's as your boot drive. I am trying to figure out the connector issue when you go from HDD to SSD. I have a couple of machines I am hesitant to upgrade due to this.

I guess I should just check out U-tube and see how it is done.

Re: SSD wins

But why switch entirely?  My dialogues with other industry experts seem to indicate the best approach in the coming years, as Moore's Law stands to make NAND-based SSD far less relevant ten years from now, is that a hybrid approach will ultimately be favored -- absent dramatic improvements in other alternatives (e.g., ReRAM).

Re: SSD wins

I am not sure if SSDs will match HDDs in price any time soon, especially when comparing high capacity storage options. But as per recent study, Enterprise SSDs are entirely different as the cheapest enterprise SSD had a cost of $1,303/GB/s and the average ranged from $3,200/GB/s to $4,200/GB/s. By comparison, Seagate's Terascale 4TB HHD has a bandwidth cost of $1,438/GB/s and the Enterprise 15K 2.5" HDD has a bandwidth of about $1,000/GB/s.

Re: SSD wins

Maybe not price, but there was a study a few years back that found that by 2024 (because of Moore's Law), SSD performance will fall to the point that it will be less cost-effective than standard HDDs.

Re: SSD wins

Once upon a time, CPUs price-performance analytics were locked with-in GHz and price. All the other metrics were ignored but, it did not take long before Intel and AMD to realize that GHz paired with prices would not deliver any long term value to the end user. And, the two companies collaborated perfectly to inform user to focus on technologies that delivered the most value to their line of work and backed it up by producing the technologies. I feel that the storage industry will have to collaborate in a similar fashion.

Re: SSD wins

Agreed, if a user has been utilizing the "Sleep" function of their PC in an attempt to speed up boot up time (trading speed for power efficiency) -- installing an SSD will provide new life for their PC. If installing SSD for all the storage requirements is not possible then, at a minimum a hybrid device should be installed.

Re: SSD Pricing Vs. HDD Costs

It certainly seems this is often a more complicated issue than it needs to be. It feels like every other week we have someone claiming the much-lauded price parity is at hand, only to have someone else claim 'this is not the price parity you're looking for' with a jedi handwave due to some ancillary issue (as you point out, apples-to-oranges comparisons are part of this). It's also true that it's odd for people to by so taken aback by SSD costing more upfront when it is, by definition, a higher-end product - and, nevertheless, we will reach that price parity at some point. Maybe not an open-and-shut case, but I'm inclined to agree with you.

Re: SSD Pricing Vs. HDD Costs

There are tremendous vested interests in play here. The result is a lot of FUD (Fear, uncertainty and doubt) The trick is to ignore the hand waving and look at the facts!

SSD's vs IBM's Nano-Tube Capacitors

with IBM's recent announcement of nano-tube capacitors for CPU's, SSD's are likely to change considerably in the next two years (proprietarily IBM, of course!)  -See this link-

InformationWeek Daily via 

Events are moving quickly and we cannot see five years; SSD's have good uses and massive storage isn't one of them, currently nor soon.  Speed and longevity are their blessings.

I use mine for saving commonly used files and the boot sequence, as well as pictures important to me (backed up, of course!)

The future of nano-tube technologies is available in most science fiction books and your imagination.  What I'll be able to sell before retirement is in the listed article.

Re: SSD's vs IBM's Nano-Tube Capacitors

Nanotubes have a lot of promise, but I suspect we are at least 5 years away from practicla products.

Based on what I've seen, though, nanotubes could give us a very densely packed 3D storage solution at very low power. I hope that works out!

Re: SSD's vs IBM's Nano-Tube Capacitors

I am new to NanoTube, little curious to find what exactly they are, battery, storage device or what. I heard that these NanoTube capacitors are efficient battery which can yield good power source.

Re: SSD's vs IBM's Nano-Tube Capacitors

Nanotubes are like a substrate for all sorts of devices. They can store data, act as very good conductors of heat to make super heatsinks, appear to be dopable to make fast transistors and have potential medical applications too.

I suggest just googling the term, but expect a lot of articles!