Hard Disk Drive (HDD) vs Solid State Drive (SSD)

SSD vs HDD

Most people now buy laptops for their computing needs and have to make the decision between getting either a Solid State Drive (SSD) or Hard Disk Drive (HDD) as the storage component. So which is best to get, an SSD or HDD? There’s no straight-forward answer to this question; each buyer has different needs and you have to evaluate the decision based on those needs, your preferences, and of course budget. Even though the price of SSDs has been falling, the price per gigabyte advantage is still strongly with HDDs. Yet, if performance and fast bootup is your primary consideration and money is secondary, then SSD is the way to go. We’ll make a comparison of SSD and HDD storage and go over the good, the bad, and the ugly of both.

What is an SSD?

We’ll make no assumptions here and keep this article on a level that anyone can understand. You might be shopping for a computer and simply wondering what the heck SSD actually means? To begin, SSD stands for Solid State Drive. You’re probably familiar with USB memory sticks - SSD can be thought of as an oversized and more sophisticated version of the humble USB memory stick. Like a memory stick, there are no moving parts to an SSD. Rather, information is stored in microchips.  Meanwhile, a hard drive uses a mechanical arm with a read/write head to move around and read information from the right location on a storage platter. This difference is what makes SSD so much faster. As an analogy, what’s quicker? Having to walk across the room to retrieve a book to get information or simply magically having that book open in front of you when you need it? That’s how an HDD compares to an SSD; it simply requires more physical labor (mechanical movement) to get information.

A typical SSD uses what is called NAND-based flash memory. This is a non-volatile type of memory. What does non-volatile mean you ask? The simple answer is that you can turn off the disk and it won’t “forget” what was stored on it. This is of course an essential characteristic of any type of permanent memory. During the early days of SSD, rumors floated around saying stored data would wear off and be lost after only a few years.  Today this is not true; you can read and write to an SSD all day long and the data storage integrity will be maintained for well over 200 years. In other words, the data storage life of an SSD can outlive you!

An SSD does not have a mechanical arm to read and write data, it instead relies on an embedded processor (or “brain”) called a controller to perform a bunch of operations related to reading and writing data. The controller is a very important factor in determining the speed of the SSD. Decisions it makes related to how to store, retrieve, cache and clean up data can determine the overall speed of the drive. We won’t get into the nitty-gritty details for the various tasks it performs such as error correction, read and write caching, encryption, and garbage collection to name a few. Yet, suffice to say, good controller technology is often what separates an excellent SSD from a simply good one. An example of a fast controller today is the SandForce SATA 3.0 (6GB/s) SSD controller that supports burst speeds up to 550MB/s read and write speeds.

Finally, you may be wondering what an SSD looks like and how easy it is to replace a hard drive with an after-market device. If you look at the images below you’ll see the top and undersides of a typically-sized 2.5” SSD. The technology is encased inside either a plastic or metal case and looks like nothing more than a battery might:

SSD Top Side

SSD Bottom Side

The form factor of the SSD is actually the same as a regular hard drive. It comes in a standard 1.8”, 2.5”, or 3.5” size that can fit into the housing and connectors for the same-sized hard drives. The connector used for these standard sizes is SATA. There are smaller SSDs available that use what’s called mini-SATA (mSATA) and fit into the mini-PCI Express slot of a laptop.

What is an HDD?

Hard Disk Drives, or HDD in techno-parlance, have been around for donkey's years relative to the technology world. HDDs were first introduced by IBM in 1956 - yes folks this is nearly 60-year old technology, thank goodness vacuum tubes for TVs didn’t last so long! An HDD uses magnetism to store data on a rotating platter. A read/write head floats above the spinning platter reading and writing data. The faster the platter spins, the faster an HDD can perform. Typical laptop drives today spin at either 5400 RPM (Revolutions per Minute) or 7200RPM, though some server-based platters spin at up to 15,000 RPM!

The major advantage of an HDD is that it is capable of storing lots of data cheaply. These days 1 TeraByte (1,024 gigabytes) of storage is not unusual for a laptop hard drive, and the density continues to grow. Cost per gigabyte is only around $0.075/GB these days for an HDD (based on buying a 4TB model), amazing when you compare it to the $1.00/GB cost for an SSD (240GB model) . If you want cheap storage and lots of it, using a standard hard drive is definitely the more appealing way to go.

When it comes to appearance, HDDs essentially look the same from the outside as SSDs. HDDs predominantly use SATA interface. The most common size for laptop hard drives is the 2.5” form factor while a larger 3.5” form factor is used in desktop computers. The larger size allows for more platters inside and thus more storage capacity. Some desktop hard drives can store up to 4TB of data! Below is an example of what an HDD looks like using the Seagate Barracuda 3TB hard drive:

HDD Top Side

HDD Bottom Side

SSD Vs HDD Comparison

Now it’s time to do some comparisons and determine which might be best for your individual needs - SSD or HDD?  The best way to compare items is a table with a side by side comparison of items in which a green box indicates an advantage:

Attribute	SSD (Solid State Drive)	HDD (Hard Disk Drive)
Power Draw / Battery Life	Less power draw, averages 2 – 3 watts, resulting in 30+ minute battery boost	More power draw, averages 6 – 7 watts and therefore uses more battery
Cost	Expensive, $1.00 per gigabyte (based on buying a 240GB drive)	Only around $0.075 per gigabyte, very cheap (buying a 4TB model)
Capacity	Typically not larger than 512GB for notebook size drives	Typically 500GB – 2TB for notebook size drives
Operating System Boot Time	Around 22 seconds average bootup time	Around 40 seconds average bootup time
Noise	There are no moving parts and as such no sound	Audible clicks and spinning can be heard
Vibration	No vibration as there are no moving parts	The spinning of the platters can sometimes result in vibration
Heat Produced	Lower power draw and no moving parts so little heat is produced	HDD doesn’t produce much heat, but it will have a measurable amount more heat than an SSD due to moving parts and higher power draw
Failure Rate	Mean time between failure rate of 2.0 million hours	Mean time between failure rate of 1.5 million hours
File Copy / Write Speed	Generally above 200 MB/s and up to 500 MB/s for cutting edge drives	The range can be anywhere from 50 – 120MB / s
Encryption	Full Disk Encryption (FDE)Supported on some models	Full Disk Encryption (FDE) Supported on some models
File Opening Speed	Up to 30% faster than HDD	Slower than SSD
Magnetism Affected?	An SSD is safe from any effects of magnetism	Magnets can erase data

If we tally up the checkmarks, the SSD gets 9 and HDD gets 3. Does that mean the that an SSD is three times better than an HDD? Not at all. As we mentioned earlier, it all depends on individual needs. The comparison here is just to lay out the pros and cons for both options. To aid you even more, here are some rules to follow when you decide which drive is best for you:

If:

• You need lots of storage capacity, up to 4TB
• Don’t want to spend much money
• Don’t care too much about how fast a computer boots up or opens programs - then get a hard drive (HDD).

If:

• You are willing to pay for faster performance
• Don’t mind limited storage capacity or can work around that - then get a solid state drive (SSD).

Today it still makes sense for a majority of typical buyers just to get an HDD inside a new computer simply due to the much cheaper cost. However, if you are an enthusiast for new technology and having top computing performance is important for you, then of course SSD is the way to go.  Eventually SSD will replace HDD as the standard storage mechanism, certainly in laptops given the advantages they present for a mobile device. We are already seeing this happen with SSD showing up as the default storage device in the new Ultrabook category.  There will always be a market for both HDD and SSD, and the perfect solution may actually be a hybrid blend of both storage solutions. The advent of mSATA SSD devices and hybrid drives that include both SSD and HDD may be the best hope for reaching storage zen and giving you the best of both worlds, but that’s a topic for another day!

Curious about which SSD or hard drive to buy? Be sure to check out our constantly updated leaderboard that has a breakdown of the best SSD in categories like value, mainstream and enthusiast.

Future of Internet In 2015

< / > Click here to embed this graphic on your website

HOW BIG IS THE INTERNET CLOUD

How big is the cloud?

Last month, ExtremeTech revealed to you The true scale of internet porn. At any one time, streaming adult videos probably utilize around 30% of the internet’s total bandwidth, which equates to around 6 terabytes of porn being consumed every second. But what about the other 70%? Netflix, YouTube, and other non-adult video sites are huge bandwidth hogs, possibly accounting for as much as 40% of internet traffic. Digital file lockers, such as Rapidshare and Mega upload  account for around 10% of traffic worldwide. Web surfing and email (and spam!) are another 15%. And then there’s cloud computing.

Today, the vast majority of web services and sites are hosted in the cloud. By this I mean that, instead of companies (such as Ziff Davis/Extreme Tech) managing their own hardware, third-party cloud storage and computing services are used. Amazon Web Services (AWS), Microsoft Azure, and Google are three prominent examples of huge cloud clusters, but there are hundreds of smaller operations that range in size from a whole data center down to a few racks.

The power of the cloud is vested in the fact that it can be coerced and shoehorned into tasks as disparate as a cloud based super computer, to webmail, to simple document storage. On a single cloud cluster, Google can host and serve petabytes of YouTube videos and store all of your email and documents. Of all the facets of the cloud, though, today we’re going to focus on cloud storage.

                  [  A MICROSOFT DATA CENTER ]

While storage might not be as sexy as terabytes of RAM and thousands of CPU cores, it is the most reliable way of measuring the size of the cloud, especially when we factor in bandwidth usage. From the total amount of storage we can also work out the cost of cloud storage — and from there, we can finally work out why the likes of Google, Microsoft, and Dropbox are falling over themselves to provide cloud storage services.

Like the porn story, we’ll first start with some theoretical numbers, and then move onto some real-world figures (and hardware) from Backblaze, a cloud backup provider.

Petabytes

For the most part, real numbers from the big companies, such as Google, Facebook, Amazon, and Microsoft, are few and far between. If you scour the web, though, some rough ballpark figures emerge:

• Facebook, in its IPO filing, said it stores over 100 petabytes (PB) of media (photos and videos). It’s not unrealistic to say that Facebook probably has a total storage of capacity well beyond that, once you factor in backups and other data (status updates, likes, and so on), possibly in the 300PB range.
• Microsoft recently admitted that Hotmail stores over 100 petabytes, and that SkyDrive, with “17 million customers,” stores 10PB of data. Like Facebook, Microsoft’s total capacity, once we factor in the rest of Azure and its web properties, is probably well over 300 petabytes.
• Megaupload is relatively tiny in comparison, apparently storing just 25 petabytes.
• Amazon, rather than giving us a nice, easy number of petabytes, instead announces the total number of objects stored by its S3 cloud storage service. As of April 2012, Amazon S3 stored 905 billion objects. If we assume an average size of 100KB, that’s around 90 petabytes; if the average size is 1MB, that’s 900 petabytes — almost an exabyte!
• Dropbox, a year ago, stored “10+ petabytes” of data. It had 25 million users then, and 100 million users today, so all things being equal the company now stores around 40PB of data.

To put these figures into perspective, an average computer probably has a 500GB or 1TB hard drive, and a petabyte is 1024TB. At the very least, then, Microsoft and Facebook data centers play host to more than 100,000 hard drives. Without building custom hardware, you can squeeze 48 drives into a 4U enclosure. After accounting for networking gear, that means you’re probably looking at around 400 hard drives per 40U rack — or 250 racks, each of which occupies around one square meter of floor space. This might sound like a lot, but when you consider that Google, Amazon, Facebook, and Microsoft regularly roll out data centers with floor plans of over 30,000 square meters (300,000+ square feet), it’s really not that much. In the grand scale of things, a lot more space is dedicated to servers (i.e. CPUs) and networking gear.

Bandwidth

Bandwidth-wise, we have even less data from the big boys. We know that, as of last year, one million files were being saved every five minutes — so today, with four times as many users, that’s 800,000 files per minute. Amazon S3, which is significantly larger than Dropbox, handles “650,000 requests per second.”

If we assume that the average file stored on Dropbox is 500KB (a mix of photos, videos, and documents) then Dropbox stores a total of 400,000 megabytes (0.4TB) per minute — or 6.7GB per second (54Gbps). We don’t have any data on how much data Dropbox sends per minute (i.e. people downloading files from their Dropbox), but it’s probably in the region of 10 to 20Gbps.

Amazon S3, which is mainly used to store static files for websites (images, style sheets, videos), probably has a lower average file size than Dropbox. If we assume an average size of 100KB per file, then 650,000 requests per second comes to a grand total of 61 gigabytes of data transferred per second, or 488Gbps. This is very close to the 800Gbps figure that we estimated for a large porn site, which equates to around 2% of total internet traffic — Amazon is pretty darn big!

Facebook and Microsoft, with between 100 and 300PB of storage each, probably fall somewhere between Dropbox and Amazon in terms of bandwidth usage — maybe 200Gbps a piece.

Backblaze

Try as we might, every cloud storage provider rebuffed our requests for information on their hardware and software setups — except Backblaze, one of the few remaining unlimited cloud backup providers. Backblaze is relatively small, but the real numbers will still astound you.

First things first: Backblaze stores a total of 32 petabytes of user data, mostly fashioned out of 3TB hard drives. For redundancy, groups of 15 drives are banded together using RAID 6, which places two parity blocks on each of the 15 disks. RAID 6 can rebuild data from the parity blocks as long as there is no more than two concurrent disk failures in a group of 15 — and yes, replacing faulty drives is by far the most important task of whoever is on call at the Backblaze data center, so that redundancy can be restored as soon as possible.

Backblaze adds 3 petabytes to its storage cluster every month, in the form of 135-terabyte “pods” — custom-designed 4U rack mounted computer cases that accommodate 45 hard drives each (pictured below). 3 petabytes per month means that Backblaze is adding roughly 22 pods per month — which equates to almost two standard 48U racks.

While you might think that the pods themselves are a major operating cost (they cost $7,384 each), hardware is really the least of Backblaze’s concerns; power, data center space, and bandwidth are far more expensive over time.

At $0.20 per kilowatt hour (kWh) each pod costs around $100 per month. Data center power is incredibly expensive, which is why many web companies are building data centers in locations with cheap power, such as Oregon. Backblaze currently hosts its servers in a third-party data center, which means it has to pay for the floorspace occupied by its cabinets; again, this works out at around $100 per pod (~$1,000 per rack). At the time of writing, Backblaze has a total of around 300 pods stored in 40 rack cabinets — so around $30,000 is spent per month on electricity, and around $40,000 is spent on floor space.

And then, of course, there’s bandwidth. At any one time, Backblaze’s routers have 12Gbps of data inbound (about 1.5 gigabytes per second), and 500Mbps (62.5MB/s) outbound. The disparity is because Backblaze is a backup service — but even so, that 500Mbps figure would suggest that hard drives fail (or data is lost) much more than I would expect. At the moment, Backblaze receives around 100 million files from its users per day, or 36.5 billion files per year — and in 2011, it restored a total of 600 million files. Unfortunately we don’t know how exactly how many restored computers that equates to, but at a conservative estimate of 5,000 files per computer (excluding Windows and program files) that comes to 120,000 very relieved backuppers.

Back in its salad days, Backblaze paid $30 per Mbps per month — now, thankfully, that figure’s down to $2/Mbps/month, which comes to a total of around $25,000 per month. Backblaze does have cheaper offers on the table from other ISPs, and again the company would save considerable money if it built its own data center.

All told, then, the total operating cost (before employees!) of a 40-petabyte cloud storage cluster is $100,000 per month, split fairly evenly between floor space, bandwidth, and power consumption.

Why cloud storage is a cut-throat business

You may have noticed that, in recent months, Microsoft, Google, Dropbox, and others are fervently fighting to be your cloud storage provider of choice. At first, I couldn’t work this out — but now, after looking at the numbers, it becomes a little clearer.

Backblaze charges $5 per month for unlimited backup — so with operational costs of $100k per month (before employees), it needs just 20,000 users to break even. Backblaze didn’t provide us with its customer count, but its CEO did tell us that the company is profitable (Backblaze has 13 employees, incidentally, and they all receive full salaries).

Another more prominent example is Dropbox, which charges $100 for 50GB of storage. Unlike Backblaze which runs its own hardware, Dropbox uses Amazon S3 for storage, which charges $0.055 per gigabyte per month for clients using more than 5 petabytes (Dropbox stores around 40PB). If the average Dropbox customer uses 25GB of his 50GB allotment, Dropbox pays Amazon $1.38 per month — and yet the service costs between $9 and $10 per month.

For cloud storage providers who operate their own data centers, such as Microsoft SkyDrive, Google Drive, and Amazon S3, the profit margins will be significantly fatter than Dropbox.

The caveat, though, is that all of these services have many more free users than paid. Dropbox, with 100 million users, is by far the largest cloud storage provider — but the vast majority of those are freeloaders. The number of paid users is probably quite small, and thus the profit margins are probably quite slim too.

Strategic dominance

The more likely reason for such feverish competition in the cloud space is strategic dominance; for Google and Microsoft, cloud computing is where the next platform war will be pitched. With Windows 8, you will log in with your Live ID and all of your documents and settings will automatically sync with the cloud, allowing you to freely roam between devices (or access your files from any web browser). Chrome OS is entirely web- and cloud-based, each successive version of Android develops deeper ties to the cloud — and of course, with Google+, the company is trying to weave as many of its web properties together as possible.

Ultimately, these companies are vying for control of your files. If you use Google Docs/Drive for word processing, then you’re much more likely to choose Chrome OS or Android, both of which are strongly tied into Google’s cloud — but if you use SkyDrive and Office Web Apps, Windows 8 and Windows Phone 7 make much more sense. In this regard, I’m not entirely sure what the future holds for “standalone” cloud storage services, such as Dropbox. If Microsoft, Google, and Apple can build cloud backup and file sharing into the operating system, what purpose does Dropbox serve?

what happens in an Internet minute?

Guess what happens in an Internet minute? 204 million emails are sent, six million Facebook pages are viewed and 1.3 million YouTube clips are downloaded

• Figures also reveal 47,000 apps are downloaded, and 20 people have their identities stolen
• Study predicts that by 2015 the number of networked devices on the Earth will be double the number of people

Astonishing figures that show the true scale of our online activity have been revealed.

The new study, by chipmaker Intel, found that more than 204 million emails are sent every minute, while 47,000 apps are downloaded and retail giant Amazon rings up around £55,000 ($83,000) in sales.

Around 20 million photos and 6 million Facebook pages are viewed, while we also watch 1.3 million video clips on YouTube.

Intel's internet minute infographic reveals exactly what we do online - with 639,800GB of data transferred

Nearly 640,00 Gb of global IP data is transferred in just one Internet minute, the researchers found.

'Computing is transforming and touching more people in a wider range of devices,' said Intel's Krystal Temple.

'But while it’s hard to miss the proliferation of portable devices, it’s what we don’t see that’s the bigger issue.

'What many don’t see is that the increase in mobile devices has had a tremendous impact on the amount of data traffic crossing the network. 

'It’s a little easier to comprehend once we think about all that’s done on a connected device like a smartphone. 

'Listening to music, watching videos, downloading photos, playing online games, refreshing Twitter feeds and status updates – all of those activities generate network traffic.'

The study also looked at how the data could expand dramatically in the future.

It predicted that by 2015, the number of networked devices is expected to be double the world’s population. 

It would take five years to view all the video content crossing IP networks each second by then

One of Google's brightly coloured data centers in Douglas Country: New figures reveal exactly what happens on the internet every minute

The chip giant also revealed it is developing new networking equipment to deal with the increase in traffic.

Codenamed 'Crystal Forest,' that will boost performance and beef up network security to handle the increasing network traffic.

'By enabling equipment manufacturers and services providers to deliver platforms that grow along with the network, Intel is also enabling consumers to stay connected on intelligent devices every Internet minute of the day,' Intel said.

ONLINE IN 60 SECONDS

More than 204 million emails are sent

Amazon rings up about £55,00 ($83,000) in sales 

Around 20 million photos are viewed and 3,000 uploaded on Flickr

At least 6 million Facebook pages are viewed around the world  

More than 61,000 hours of music are played on Pandora 

More than 1.3 million video clips are watched on YouTube