The hardest part of choosing a new server, whether it’s a dedicated server or virtual private server, is the selection of the right hardware that will fit your needs. If you’re like most people, then you try to purchase maximum CPU cores for your budget. You also check how much RAM you’ll get. You’re cautious about having enough storage capacity. But there is one crucial element that most people forget – the storage type.
Not all drives are made equal. There is a huge difference in price and
performance between NVMe, SSD and HDD storage. In this article, we’ll guide you
through different types of drives so that you can pick the best one for you.
HDD, SSD, NVMe: From Spinning Platters to
Lightning-fast Express Drive
HDD: Hard Disk Drives
The oldest of them
all, hard disk drives (HDD), is the only one of three based on moving parts – spinning
platters and moving needles, recording data on different sectors of the metal
disc. The technology itself goes way back to the 50s, when it was introduced by
IBM. Although cheapest on the list, they’re also slowest when it comes to
read-write operations. Most HDDs can’t exceed maximal S-ATA II speed of ~270
MB/s. HDD is the ultimate solution in case you want to store your data for as
little money as possible. But you’ll have to wait more when reading/writing
data. Although slower, they’re still popular. Our customers can still encounter
HDD drives in Storage VPS or
while configurating Dedicated Servers.
Capacity of storage
varies greatly, but most drives range somewhere between hundreds of Gigabytes
to few Terabytes. In case of virtual instances, we at Contabo offer hard disk
space starting from 300 GB.
Home users are sometimes concerned about HDDs’ sensibility to outside shocks or
sudden movements. But that’s not really a concern in the case of data centers,
because servers are fixed to racks or shelves and not moved around.
SSD: Solid State Drives
This newer type of
storage contains no movable parts as it’s flash-based. It’s the same technology
you may know from a USB stick. Although the storage technology itself is
different, it still uses the same connection interface to the motherboard.
There still has to be an S-ATA controller between the drive and motherboard.
The SSD read-write speed is significantly faster compared to HDD as it can
reach 550 Mb/s.
The compact size of
SSD drivers has huge implications for both personal computing and data centers.
SSDs are an ideal fit for notebooks and other devices with limited space. The
introduction of SSD allowed putting more separate drives into one physical
server. Although this improvement doesn’t necessarily increase storage
capacity, it is helpful in terms of redundancy and RAID configuration. For that
reason, SSD is the standard storage type for data centers. At Contabo, you can
find SSD drives in our High-Performance
VPS, VDS or bare metal servers.
And the price per capacity ratio? SSD is somewhere in the middle between HDD
and NVMe. Although there are exceptions, like this $40 000 drive from
Nimbus, with 100 TB capacity.
NVMe: Non-Volatile Memory Express
Introduced in 2013,
the new “express” drive is the fastest type available on the market. Similar to
SSDs, it’s a type of flash storage that contains no moving parts. The “NVM”
stands for non-volatile memory, a memory that can store your data even after
power is removed. It still uses the same architecture as SSD, but it’s
connected directly to the motherboard via PCI express socket. Hence, the small
letter “e” at the end.
It can run up to 32
GB/s if we take into consideration the newest PCIe 4.0 connection and 16
separate lanes. NVMe is still far from reaching its full potential though. At
Contabo, we’re offering NVMe drives for all types of servers,
specifically VPS, VDS and Dedicated Servers.
Why Exactly is NVMe so Much Faster Than
Its Predecessors?
In short: Because it’s
based on faster PCIe interface, there is no intermediary between the drive and
the motherboard. It can also process a lot more commands at the same time.
Architecture
As flash-based SSD
technology became mainstream, users benefited greatly from having faster data
transfers. Still, they were dependent on the old S-ATA interface. They still
had to use the S-ATA (or SAS) controller in order to communicate with the CPU
and motherboard. Then in 2007, engineers at Intel got the brilliant idea to
connect the same SSD drive to motherboard using a PCI Express slot, which was
at that time predominantly used for connecting graphic cards, sound cards or
additional network interface cards.
As a result, the new
type of storage doesn’t need the S-ATA (SAS) controller and can communicate
directly with the motherboard. On top of that, the use of the PCIe allows NVMe
to use multiple lanes. Lanes connect PCIe to the motherboard. Each of the lanes
uses two wires for sending and two for receiving information simultaneously,
hence greater potential for faster exchange.
Queue Depth and Simultaneous Tasks
Not only NVMe doesn’t
need a S-ATA or SAS controller, but it also significantly improved the command
structure. While SSD only works with 1 command queue, NVMe simultaneously uses
64k command queues. And while SSDs can only send 32 commands per that single
queue, NVMe sends up to 64k commands per EACH queue! NVMe allows a higher
number of command queues, which means that it can process many more commands at
the same time. While SSDs read/read operations are waiting in line, NVMes are
juggling many different tasks at once.
The queue depth is
especially important for customers who run complex web applications, such as
large e-commerce or SaaS application. Then, the whole application can be
divided into various different microservices that
are processed independent on each other. For instance, think of an eCommerce
store. Each customer generates a string of database queries and read-write
operations just by browsing the website. Not to mention the whole checkout
process. Storage is involved in all these operations and the IOPS visibly
impacts customer experience. NVMe can handle more of those tasks separately and
with great speed, hence allowing lower latency.
Overall, NVMe works significantly faster with workloads like:
- Website hosting – so visitors to your website get a swifter
response time
- SaaS apps – so users of your software can browse your app
more smoothly
- Database application – so that you can collect and recall data more
quickly
- E-commerce software – loading pages of products will be quicker,
hence fewer people will leave your website
- Video files – when editing or exporting video files, you’ll save a ton of time
Here are some
impressive stats from one of the most prominent data storage manufacturers,
Kingston. As you can see in the picture, the latency is much higher
with traditional SSDs. In other words, the server running MySQL data base
performs much better. The more threads you’re running simultaneously, the more
important the difference is.
Recap: 3 reasons why is NVMe so fast
- No controller: There is no SAS
or S-ATA controller between the motherboard and the drive that would slow
down the communication
- Queue depth: Thanks to the
improved command structure, NVMe is so much better at working with various
tasks simultaneously
- Multiple lanes: The PCI express
standard offers multiple lanes, up to 16, boosting performance
significantly
Purchasing Your New Storage
In the previous part,
we’ve described technological differences between all types of storage. Let’s
briefly discuss the practical side in case you’re still in doubt about which
one to purchase:
HDD: The Best Price / Quality Ratio
If your only criterion
is dollars per GB, then you can just go with proven HDDs. Although slow, they
offer enough capacity for all types of workloads. Ideal in case you need to
park your data somewhere as a backup.
To show you how inexpensive HDD servers are, let’s have a look at one of our
most popular Storage VPS: VPS 700.
For $10.99 a month, you’ll get 700 GB drive. Great low-price solution in case
you don’t need super fast access your data, therefore you don’t mind slower
read/write speed.
NVMe: When Speed is the King
NVMe is by far the
fastest storage on the market. The difference is so staggering that the whole
operating system becomes visibly more responsive when installed on top of NVMe.
As stated in the previous section, NVMe makes a difference with workloads, such
as SaaS apps or database systems. Large individual files are also transferred
much faster, which makes it a popular option for video editors.
If you need to run
applications where speed is the key, go for NVMe. For example, VPS S equipped with NVMe offers you a
fast storage for just €4.99/$6.99.
SSD: The Versatile All-rounder
The SSD drive is
somewhere in the middle in terms of performance. Although they can’t compete
with NVMe speed, they offer in general much more storage for the same price.
For instance, you can
purchase our VPS S equipped
with an SSD and get 4x more storage space for the same price as NVMe drive with
the equal capacity.
Wrapping up
In this article, we
explained all three currently available types of storage: HDD, SSD and NVMe.
While hard disc drives still use spinning platters, the other two types contain
no moving parts. We also explained, that NVMe is a type of SSD memory, but it
uses a different type of interface.
|
Moving plates |
Solid flash architecture |
|
|
SATA/SAS Controller |
HDD |
SSD |
|
PCIe Interface |
|
NVMe |
Architecture comparison between old “moving
parts” and flash-based types of drives.
NVMe is so fast
because its whole infrastructure is different than SSD or HDD. Having no
controller in between drive and motherboard makes data transfer faster. Also,
thanks to robust queue depth, NVMe can process many more commands at the same
time. There is no doubt that NVMe will become a standard storage type in the
foreseeable future. Benefits are apparent – much lower latency, thanks to
infrastructure that is faster than most common SSDs.
For now, NVMe storage
remains considerably more expensive than standard SSDs. We recommend that you
consider purchasing them if you run demanding web applications or regularly
work with large video files. Other than that, SSDs and HDDs are still
perfectly viable options for many use cases.
Source: https://contabo.com/blog/nvme-vs-ssd-vs-hdd/
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