自从第一批 5 MB 硬盘由货机交付并用叉车移动以来，我们已经走了很长一段路。如今，您有很多很好的选择来满足您的数据存储需求。其实，你可能有太多的选择！这种多样化的选择可能会导致一些混乱。
今天购买硬盘时，您有三种驱动器类型：SSD、HDD或SSHD。这种首字母缩略词汤可能会诱使您放弃并重新使用粘土片，但我们会帮助您找出最适合您需求的方法。
什么是 SSD、HDD 和 SSHD
所有这一切中显而易见的第一步是解释这三种驱动器类型是什么，并扩展这些首字母缩写词的实际含义。
SSD 是固态硬盘。(SSDs are Solid State Drives.)它们没有任何移动部件，并使用固态闪存(solid state flash memory)。
HDD 是硬盘驱动器。(HDDs are Hard Disk Drives.)这些是直到最近才成为标准的传统机械驱动器。它使用覆盖有磁性物质的旋转盘片来存储数据。微小(Tiny)的读/写头在这些磁盘的表面掠过，漂浮在空气垫上，空气垫只有头发那么宽。
SSHD 是固态混合驱动器。(SSHDs are Solid State Hybrid Drives.)名称的“混合”部分是指这些驱动器包含固态内存和旋转机械磁盘的事实。驱动器内的智能(Clever)软件会在后台确定哪些文件应加载到固态内存中。因此，当您想要访问已加载到固态缓存上的文件时，您将获得与纯SSD相似的性能。
表现
说到性能，在比较时有一个明确的层次结构。
固态硬盘(Solid State Drives)
在所有比较中， SSD(SSDs)都是最快的驱动器类型。优质的SATA 3 SSD或多或少会达到连接类型的限制，读写速度约为 600MB/s。
但SSD(SSDs)也有其他格式，例如NVME。读写速度约为 3500 MB/sNVME SSD现在很常见，而运行速度超过 5500 (NVME SSDs)MB/s新一代驱动器即将问世。
固态混合驱动器(Solid State Hybrid Drives)
SSHD 只能用作SATA驱动器，因此它们永远不会超过 600MB/s 的连接速度限制。此外，它们只能在短时间内达到SSD速度。基本上只要SSD缓存中有数据。因此， SSD(SSD)缓存越大，它可以维持高数据速度的时间就越长。
它还取决于SSHD是否已将正确的文件预加载到缓存中。如果没有，您将退回到标准硬盘驱动器速度。
硬盘驱动器(Hard Disk Drives)
传统硬盘驱动器是最慢的。虽然高端 7200 RPM驱动器可以达到 230MB/s 左右，实验性驱动器已显示达到近 500MB/s，但笔记本电脑或台式计算机中的典型 5400 RPM驱动器远不及此。(RPM)30MB/s 和 110MB/s 之间的速度更为典型。
物理尺寸
SSD 已使用SATA连接器生产为 3.5 英寸和 2.5 英寸标准驱动器尺寸。在这种情况下，它们占用的体积与这些尺寸的机械驱动器相同。但是，这是为了驱动器托架的兼容性，实际上不需要它们那么大。
NVME格式的驱动器大约与台式 PC内存(RAM)一样大，并且紧紧地靠在主板上。这意味着它们根本不占用驱动器托架。
SSHD(SSHDs)和HDD(HDDs)仅适用于 3.5 英寸和 2.5 英寸外形尺寸。它们也比SSD(SSDs)重得多，因此它们将增加系统的体积，至少相对而言是这样。
成本和容量
SSD(SSDs)的成本在过去几年中一直在下降，但优质驱动器仍将是所有驱动器类型中每 GB 价格最高的。SSD(SSDs)的最大容量也相对有限。
目前最大的驱动器大小为 2TB，但对于这么大的空间，价格却令人瞠目结舌。因此，系统通常配备 250GB 到 500GB 的驱动器。在 100GB 视频游戏和4K 视频(4K video)的世界中，这并不算多！
SSHD(SSHDs)和HDD(HDDs)的定价相似，由于包含少量SSD存储和更复杂的电子设备和固件， SSHD的成本更高。(SSHDs)这两种驱动器类型的每 GB 成本都很低，而且容量很大，高端时超过 10 TB。
可靠性
当谈到这些不同驱动器类型的可靠性时，水有点浑浊。关于机械驱动器的可靠性，我们拥有大量数据。这些通常具有 100,000 小时的MTBF（平均故障间隔时间）(MTBF (Mean Time Between Failures))。故障通常是由机械部件磨损引起的。因此，即使您不经常使用硬盘驱动器，但它保持通电状态，它最终也会失败。
从理论上讲， SSD(SSDs)应该可以永久使用，但是您在消费类驱动器中获得的更实惠的SSD内存类型会在您每次向其写入数据时磨损一点。这是一个复杂的话题，因此我们建议您阅读有关SSD 磨损和撕裂的一切您需要了解(Everything You Need To Know About SSD Wear & Tear)的内容，以更好地掌握该问题。
在现代大容量SSD(SSDs)中，这并不是真正的问题。SSD酷刑测试表明它们的持续时间远远超出了额定数据写入寿命。但是，它确实成为具有小型SSD缓存的(SSD)SSHD的一个问题，该缓存不断被写入作为临时保存空间。
推荐用例
既然我们已经介绍了这些不同驱动器的优点和弱点，现在是时候讨论哪些驱动器最适合哪些用例了。
SSD(SSDs)最适合用作托管操作系统和受益于SSD速度的应用程序的系统驱动器。这些将包括视频编辑器、生产力应用程序，当然还有视频游戏。由于价格昂贵，SSD(SSDs)被浪费在媒体文件或数据归档上。
(SSHDs)对于只有一个驱动器托架的笔记本电脑来说，SSHD确实是一个明智的选择。无论是因为您的预算有限还是您需要大量内部空间，SSHD都能提供一些日常性能提升，同时还提供大量廉价存储。
HDD驱动器非常适合存储大型媒体文件、视频游戏和其他应用程序的备份以及不需要使用SSD速度的任何其他数据类型。这些驱动器很便宜，如果您使用不经常运行的外部HDD驱动器，它们也可以提供良好的备份解决方案。(HDD)
在可以有多个驱动器的系统中，今天的最佳解决方案似乎是一个SSD主驱动器，一个大型HDD作为辅助大容量存储驱动器。然而，随着SSD价格的下降和尺寸的增加，未来似乎确实是纯固态的。我们还没有完全实现，但是SSD存储比HDD存储更便宜的那一天可能不会像您想象的那么遥远。
SSHD vs SSD Drives: Which Is Better?
We have сome a long way since those νery first 5 MB hard drives were dеlivered bу cargo plane and moved around with forklifts. Thеse days you have рlenty of great оptions for your data storage needs. Actually, you probably have too many choices! This variеty of choices can lead to some confusion.
When buying a hard drive today, you have three drive types: SSD, HDD or SSHD. This acronym soup might tempt you to just give up and go back to clay tablets, but we’ll help you figure out which is best for your needs.
What Are SSDs, HDDs and SSHDs
The obvious first step in all of this is to explain what these three drive types are and expand on what those acronyms actually mean.
SSDs are Solid State Drives. They have no moving parts whatsoever and make use of solid state flash memory.
HDDs are Hard Disk Drives. These are the traditional mechanical drives that were standard until quite recently. It uses spinning platters covered in a magnetic substance to store data. Tiny read/write heads flit across the surface of these disks floating on a cushion of air a fraction of a hair’s width.
SSHDs are Solid State Hybrid Drives. The “hybrid” part of the name refers to the fact that these drives contain both solid state memory and spinning mechanical disks. Clever software inside the drive figures out which files should be loaded onto the solid state memory in the background. So when you want to access files that have been loaded onto the solid state cache, you’ll get similar performance to a pure SSD.
Performance
Speaking of performance, there’s a clear hierarchy when it comes to this comparison.
Solid State Drives
SSDs are the fastest type of drive in every comparison. A good quality SATA 3 SSD will more or less hit the limits of the connection type with read and write speeds at around 600MB/s.
But SSDs also come in other formats, such as NVME. NVME SSDs with read and write speeds around 3500 MB/s are commonplace now and a new generation of drive that runs in excess of 5500 MB/s is on the horizon.
Solid State Hybrid Drives
SSHDs are only available as SATA drives, so they can never exceed the 600MB/s speed limit of the connection. Also, they can only achieve SSD speeds for short bursts of time. Basically for as long as the SSD cache has data in it. So the larger the SSD cache, the longer the amount of time it can sustain high data speeds.
It also depends on whether the SSHD has pre-loaded the right files into the cache. If it hasn’t you’ll fall back to standard hard drive speeds.
Hard Disk Drives
Traditional hard drives are the slowest of the bunch. While high-end 7200 RPM drives can attain around 230MB/s and experimental drives have been shown hitting almost 500MB/s, the typical 5400 RPM drive you’ll find in a laptop or desktop computer comes nowhere near that. Speeds of between 30MB/s and 110MB/s are much more typical.
Physical Size
SSDs have been produced in 3.5” and 2.5” standard drive sizes using the SATA connector. In which case they take up the same volume as mechanical drives in those sizes. However, that’s for drive bay compatibility, there’s no actual need for them to be that large.
NVME format drives are about as large as a stick of desktop PC RAM and sit tightly against the motherboard. Which means they take up no drive bays at all.
SSHDs and HDDs are only available on 3.5” and 2.5” form factors. They are also significantly heavier than SSDs, so they will add to the bulk of the system, at least in relative terms.
Cost and Capacity
The cost of SSDs have come tumbling down over the last few years, but a quality drive will still command the highest price per gigabyte of any drive type. SSDs are also relatively limited in their maximum capacity.
The largest drives are currently 2TB in size, but have eye-watering prices for that much space. So typically systems come equipped with 250GB to 500GB drives. That’s not much in a world of 100GB video games and 4K video!
SSHDs and HDDs have similar pricing, with SSHDs costing a bit more thanks to the inclusion of a small bit of SSD storage and more sophisticated electronics and firmware. Both of these drive types have a low per-gigabyte cost and are offered in huge capacities, exceeding 10 TB at the high end.
Reliability
The water is a little muddy when it comes to the reliability of these different drive types. We have a huge amount of data when it comes to the reliability of mechanical drives. These typically have a MTBF (Mean Time Between Failures) of 100,000 hours. Failure is usually caused by mechanical components wearing out. So even if you don’t use your hard drive much, but it stays powered on, it will fail eventually.
Theoretically SSDs should last forever, but the more affordable type of SSD memory you get in consumer drives wears out a little every time you write data to it. This is a complicated topic, so we suggest you read Everything You Need To Know About SSD Wear & Tear to get a good grasp of the issue.
In modern high capacity SSDs, it’s not really a problem. SSD torture tests have shown them lasting far beyond their rated data writing lifespans. However, it does become a point of concern on an SSHD with a small SSD cache that is constantly being written to as a temporary holding space.
Recommended Use Cases
Now that we’ve covered the strong and weak points of these various drives, it’s time to talk about which drives are best for which use cases.
SSDs are best used as system drives that host the operating system and applications that benefit from SSD speeds. These would include video editors, productivity applications and of course video games. Since they are expensive, SSDs are wasted on media files or data archiving.
SSHDs are really only a sensible choice for laptop computers that only have a single drive bay. Whether it’s because your budget is limited or you need a lot of internal space, an SSHD offers some day-to-day performance increases while also offering plenty of cheap storage.
HDD drives are perfect to store large media files, backups of video games and other applications and any other data types that don’t require SSD speeds to use. These drives are cheap and if you use external HDD drives that don’t run constantly, they also make for good backup solutions.
In systems that can have multiple drives the optimal solution today seems to be an SSD main drive, with a large HDD as a secondary mass storage drive. However, with SSD prices going down and sizes going up, the future does seem to be purely solid state. We aren’t quite there yet, but the day when SSD storage is cheaper than HDD storage may not be as far away as you’d think.
