汉英对照:
Chinese-English Translation:
选购SSD固态硬盘类型的移动硬盘，比常规的机械式移动硬盘传输速率更高更快，然而由于速度的提升则需要考虑移动硬盘的接口类型、传输协议，相对而言SSD移动硬盘也更加昂贵，选购时需要根据自己实际需求选择。 如果您需要快速的本地存储大量文件（例如，随身携带的音乐或电影，或者在手机或相机上收集的所有这些图片和视频），则可以考虑使用便携式固态驱动器（SSD），而不是而不是 便携式硬盘。
The transmission rate of the SSD type of mobile hard disk is higher and faster than that of the conventional mechanical mobile hard disk. However, due to the improvement of the speed, the interface type and transmission protocol of the mobile hard disk need to be considered. Relatively speaking, SSD mobile hard disk is also more expensive, so you need to choose according to your actual needs. If you need to quickly store a large number of files locally (for example, music or movies you carry with you, or all of these pictures and videos collected on your phone or camera), consider using a portable solid-state drive (SSD) instead of a portable hard disk.
曾经价格过高的各种固态硬盘在过去几年中价格一直在下跌，而外部固态硬盘已成为外部硬盘驱动器的替代产品，其速度高达后者的五倍，并且耐用性更高。它们没有可以旋转的金属盘片，也没有任何需要移动到盘片上特定点才能找到所需文件的读/写头。而且由于缺乏活动部件，因此与最坚固耐用的硬盘驱动器相比，便携式固态硬盘通常更紧凑，更薄，并且更适合频繁旅行和意外掉落。
The prices of once expensive SSDs have been falling in the past few years, and external SSDs have become an alternative to external hard drives, which are five times faster and more durable. They don’t have metal disks to rotate, and they don’t have any read / write heads that need to be moved to specific points on the disks to find the required files. And because of the lack of moving parts, portable solid-state drives are generally more compact, thinner, and more suitable for frequent travel and accidental falls than the most robust hard drives.
不妨考虑 SSD
Consider SSD
与在移动磁头访问的旋转磁盘上存储数据的硬盘驱动器不同，固态驱动器使用“持久”闪存单元的集合来保存数据。这些类似于组成计算机 RAM 的硅，但是当电源切断时它们会保留您的数据。
Unlike hard drives that store data on rotating disks accessed by mobile heads, solid-state drives use a collection of “persistent” flash memory cells to hold data. These are similar to the silicon that makes up your computer’s ram, but they retain your data when the power is turned off.
由于硬盘驱动器是使用成熟技术的机械设备，因此您可以获得相对大量的存储容量。但是，使硬盘具有诱人价值的同一技术成为他们在旅途中使用时的最大责任。如果卸下驱动器，则可能会损坏内部机械装置并导致数据无法访问。相比之下，如果在读取或写入数据时摇动 SSD，则不会有文件损坏和无法读取的风险。
Because hard drives are mechanical devices that use mature technology, you can get relatively large amounts of storage capacity. But the same technology that makes hard drives attractive is their biggest responsibility when they use them on the road. If the drive is removed, internal mechanisms may be damaged and data cannot be accessed. In contrast, if the SSD is shaken while reading or writing data, there is no risk of file corruption and unreadability.
而且，硬盘驱动器速度较慢，因为它们必须物理访问您的数据。从闪存读取数据比从旋转盘上的特定点读取数据快多少？消费类硬盘的典型吞吐量在 100MBps 至 200MBps 的范围内。（一个因素是旋转速度-在外部驱动器中，5,400rpm 的设备比 7,200rpm 更为普遍，也更实惠。）
Also, hard drives are slower because they have to physically access your data. How much faster is reading data from flash memory than from a specific point on a rotating disk? The typical throughput of consumer hard disks ranges from 100 Mbps to 200 Mbps. (one factor is rotational speed – 5400 RPM devices are more common and affordable than 7200 RPM devices in external drives.)
即使对于运行中的外部 SSD，我们的典型基准测试结果也显示出超过 400MBps 的速度。实际上，这意味着您可以在几秒钟内（而不是使用外部硬盘驱动器花费几分钟）将数千兆字节的数据（例如 4GB 故事片或一年的家庭照片）移动到外部 SSD。
Even for running external SSDs, our typical benchmark results show speeds above 400 Mbps. In fact, this means that you can move thousands of megabytes of data (such as 4GB feature films or a year’s home photos) to an external SSD in seconds rather than minutes using an external hard drive.
不过，您确实要为此速度和耐用性付出代价。需要 2TB 便携式硬盘吗？您可以从 Seagate 和 Western Digital 等主要品牌中找到一款，价格低至 60 美元。另一方面，一个 2TB 的外部 SSD 将花费您大约 300 美元。这不是打字错误-您将为相同数量的存储支付几乎五倍的费用。如果速度，弹性和便携性对您至关重要，那么所有这些额外的钱可能就是值得的。如果不是，请格外小心。在考虑是否购买外部 SSD 时，请确保您知道自己（以及银行帐户）正在使用什么。
However, you do pay for speed and durability. Do you need a 2TB portable hard disk? You can find one from major brands such as Seagate and Western Digital for as low as $60. On the other hand, a 2TB external SSD will cost you about $300. This is not a typo error – you will pay almost five times as much for the same amount of storage. If speed, flexibility, and portability are critical to you, all this extra money may be worth it. If not, be extra careful. When considering whether to purchase an external SSD, make sure you know what you (and your bank account) are using.
如今，外置 SSD 随手可得，而且比几年前便宜，但它们可能永远无法完全替代硬盘。物理上较大的外部驱动器（设计用于留在您的办公桌上或服务器壁橱中）仍然大部分内部使用 3.5 英寸磁盘驱动器，与 SSD 相比，它们具有更高的容量和更低的价格 。
External SSDs are now readily available and cheaper than they were a few years ago, but they may never completely replace hard drives. The physically larger external drives (designed to stay on your desk or server closet) still mostly use 3.5 inch disk drives internally, with higher capacity and lower price than SSDs.
由内而外：了解外部 SSD 接口
From the inside out: understanding the external SSD interface
外部固态驱动器实质上是带有外壳的内部固态硬盘（与笔记本电脑或台式机内部电源相同）。结果，外部驱动器使用两种内部“总线类型”之一，它们在某种程度上决定了它们的峰值速度：串行 ATA（SATA）或 PCI Express（PCIe）。近来，后者通常与非易失性存储器 Express（NVMe）相关联，该协议针对 SSD 的特性进行了优化，并加快了数据传输速度。
An external solid-state drive is essentially an internal solid-state drive with a case (the same as the internal power supply for a laptop or desktop). As a result, external drives use one of two internal “bus types,” which to some extent determine their peak speed: Serial ATA (SATA) or PCI Express (PCIe). Recently, the latter is usually associated with non-volatile memory Express (nvme), which is optimized for SSD characteristics and speeds up data transmission.
基于 SATA 的驱动器往往便宜一些。它们的速度也较慢，但对于大多数用户的日常应用程序来说还是不错的。基于 SATA 的 SSD 通常以约 500MBps 的峰值读写速度达到最高，仅略低于 USB 3.0 接口的上限。（稍后会提供更多信息。）但是，如果您打算经常传输大文件（例如视频），那么您可能会希望使用基于 PCIe / NVMe 的外部 SSD。这也与您将 SSD 插入的端口有关。
SATA based drives tend to be cheaper. They’re also slow, but they’re good for most users’ everyday applications. SSD based on SATA usually reaches the highest reading and writing speed of about 500mbps, which is only slightly lower than the upper limit of USB 3.0 interface. (more information will be provided later.) However, if you plan to transfer large files (such as video) frequently, you may want to use an external SSD based on PCIe / nvme. This also relates to the port on which you insert the SSD.
便携式 SSD 的销售商并不总是指出驱动器是基于 SATA 还是 PCIe。但是，检查规格可能是一个赠品。如果驱动器以 400MBps 至 550MBps 的顺序读写速度达到最高，则很可能是基于 SATA 的。800MBps 或更高的速度表示基于 PCIe 的驱动器。
Vendors of portable SSDs do not always indicate whether drives are based on SATA or PCIe. However, checking specifications can be a gift. If the drive reaches the highest read / write speed in the order of 400Mbps to 550mbps, it is likely to be based on SATA. 800 Mbps or higher indicates a PCIe based drive.
SSD 和 USB：如此多的精妙之处
SSD and USB: so many subtleties
可以说，如何连接到 PC 或 Mac 比外部 SSD 内的存储机制更重要。如今，几乎所有外部 SSD 都可以插入某种类型的 USB 端口或 Thunderbolt 3 端口。
It can be said that how to connect to a PC or Mac is more important than the storage mechanism within the external SSD. Today, almost all external SSDs can be plugged into some type of USB port or thunderbolt 3 port.
las，USB 的种类繁多，足以使您的头旋转-这些天，由于 USB 周围的术语混乱而使情况变得更糟。例如，当今的 USB 3.2 标准在所有意图和目的上都与 USB 3.1 相同，只是对其进行了更名。（这会变得更好：即将推出的 USB 4 将吸收 Thunderbolt3。）也就是说，您仍然会在 PC 或 Mac 以及许多 SSD 上看到较旧的 USB 术语，因此您需要知道哪个术语与什么相关。
LAS, there’s a wide variety of USB that’s enough to make your head spin – things are getting worse these days due to the jargon surrounding USB. For example, today’s USB 3.2 standard is the same as USB 3.1 in all intents and purposes, but renamed. (this will get better: the upcoming USB 4 will absorb thunderbolt 3.) That is, you will still see older USB terms on your PC or Mac and many SSDs, so you need to know which term is relevant to what.
首先，您可能会忘记 USB 2.0，其理论带宽为每秒 60 兆字节（60MBps），即使对于磁盘驱动器来说也是一个瓶颈。（这些端口仍在台式机和笔记本电脑上存在，但是如果可以帮助的话，您将不希望将其与任何便携式驱动器一起使用，并且所有 USB 接口的外部 SSD 都将支持某些 USB3。）最常用的端口适用于所有条带的外部驱动器是 USB 3.0，其理论峰值带宽为 640MBps。直到最近，大多数 SSD 的实际传输速度都达到了 450MBps 或更低的水平，因此这些端口还不错。
First, you may forget that USB 2.0 has a theoretical bandwidth of 60 megabytes per second (60 Mbps), which is a bottleneck even for disk drives. (these ports still exist on desktops and laptops, but you won’t want to use them with any portable drives if you can help, and all external SSDs with USB interfaces will support some usb3.) The most commonly used port for all stripes is USB 3.0, which has a theoretical peak bandwidth of 640 Mbps. Until recently, most SSDs had actual transmission speeds of 450 Mbps or less, so these ports were good.
除了 640MBps，您还将看到 USB 3.0 的理论数据速率描述为 5Gbps。（这是每秒的千兆字节，而不是千兆字节。）您可能还会看到该接口称为 USB 3.1 Gen 1 或 SuperSpeed USB 5Gbps （实际上，这三个都是相同的），以区别于 USB 3.1 Gen 2 或 SuperSpeed USB 10Gbps，这将上限提高到（您猜对了！）10Gbps。在撰写本文时，USB 3.1 Gen 2 是消费类外部 SSD 中广泛可用的最新版本。PCIe 外部 SSD 可以利用额外的 5Gbps 带宽，但是您需要具有一个支持规格的 USB 端口，才能看到额外的速度优势。
In addition to 640mbps, you will also see that the theoretical data rate of USB 3.0 is described as 5Gbps. (this is gigabytes per second, not gigabytes.) You may also see that the interface is called USB 3.1 Gen 1 or superspeed USB 5Gbps (in fact, all three are the same) to distinguish it from USB 3.1 Gen 2 or superspeed USB 10Gbps, which raises the upper limit to (you guessed it!) 10Gbps。 At the time of writing, USB 3.1 Gen 2 is the latest version widely available in consumer external SSDs. The PCIe external SSD can take advantage of the additional 5Gbps bandwidth, but you need to have a USB port that supports specifications to see the additional speed advantage.
在 2019 年， USB 实施者论坛宣布 USB 3.1 版本被更名为 USB 3.2。进行此更改后，您将需要了解以下四种模式：5Gbps（USB 3.2 Gen 1），10Gbps（USB 3.2 Gen 2×1 和 Gen 1×2），前者在一个“通道”上实现了 10Gbps 的速度，后者通过两个 5Gbps 达到了 10Gbps 的速度。通道）和 20Gbps（USB 3.2 Gen 2×2，又名 SuperSpeed USB 20Gbps）。所有这些都向后兼容 USB 3.0 端口。性能只会下降到两者中的较低者（驱动器支持的规格，或系统端端口的规格）。
In 2019, the USB implementer forum announced that USB 3.1 was renamed USB 3.2. After making this change, you will need to understand the following four modes: 5Gbps (USB 3.2gen 1), 10Gbps (USB 3.2gen 2 × 1 and Gen 1 × 2), the former achieves 10Gbps speed on one “channel”, and the latter achieves 10Gbps speed through two 5Gbps. Channel) and 20gbps (USB 3.2 Gen 2 × 2, also known as superspeed USB 20gbps). All of these are backward compatible with USB 3.0 ports. Performance will only degrade to the lower of the two (drive supported specifications, or system side port specifications).
到目前为止，您不会在 PC 上看到许多支持 USB 3.2 Gen 2×2 的端口（某些较新的高端台式机主板有此端口），但是随着 2020 年代的到来，新的 USB 规格将变得越来越重要。
So far, you won’t see many USB 3.2 Gen 2 × 2 ports on your PC (some newer high-end desktop motherboards do), but with the advent of the 2020’s, new USB specifications will become more and more important.
然后是 Thunderbolt 3 接口
Then there is the thunderbolt 3 interface
Thunderbolt 3 提供 40Gbps 的超高带宽。所有最新型号的 Mac 以及越来越多的高档 Windows 笔记本电脑上都可以找到兼容的端口。这些端口实际上是 USB Type-C 连接器，其顶部具有 Thunderbolt 支持。但是，Thunderbolt 3 SSD 与仅支持 USB 传输的 USB C 型端口不向后兼容。该端口必须专门支持 Thunderbolt 3；寻找端口和电缆连接器上的小闪电
Thunderbolt 3 provides an ultra-high bandwidth of 40Gbps. More and more of the latest models of windows compatible laptops are available on Macs. These ports are actually USB type-C connectors with thunderbolt support at the top. However, thunderbolt 3 SSD is not backward compatible with USB type C ports that only support USB transfers. The port must specifically support thunderbolt 3; look for small lightning on ports and cable connectors
Thunderbolt 3 是最不常见的外部 SSD 接口，使用它的 SSD 通常适合 Mac 用户。您会在以速度为中心的驱动器（例如 Samsung Portable SSD X5） 和某些台式机驱动器上找到 Thunderbolt 3，这些 驱动器可能包含多个 RAID 格式的 SSD。
Thunderbolt 3 is the least common external SSD interface, and its SSD is usually suitable for Mac users. You will find thunderbolt 3 on speed centric drives (such as Samsung portable SSD x5) and some desktop drives that may contain multiple SSDs in raid format.
大多数工作日的 SSD 都无法接近饱和该接口，因此除非您特别需要速度，否则没有必要为 Thunderbolt 3 驱动器支付额外费用。您可以在 Thunderbolt 3 端口上使用 Type-C USB 驱动器，因此您不必在仅具有这些端口的 PC 上购买 Thunderbolt 3 驱动器，例如 Mac。
Most weekday SSDs are not nearly saturated with the interface, so there is no need to pay extra for thunderbolt 3 drives unless you specifically need speed. You can use the type-C USB drive on the thunderbolt 3 ports, so you don’t have to purchase a thunderbolt 3 drive on a PC with only these ports, such as a Mac.
最后一个接口皱纹：物理 USB 端口
Last interface wrinkle: physical USB port
目前，系统端的物理 USB 端口采用 USB Type-A（熟悉的，较旧的矩形）和 USB Type-C（较小且大致为椭圆形）的形式。此物理类型不一定表示端口支持哪种特定的 USB 传输速率规范。但是您需要确保可以插入所获得的内容。
At present, USB type-A (familiar, older rectangle) and USB type-C (small and oval) are used as the physical USB ports on the system side. This physical type does not necessarily indicate which specific USB transfer rate specification the port supports. But you need to make sure that you can insert what you get.
许多 SSD 在计算机端都附带两种电缆（A 型和 C 型），或者一根电缆加一个适配器。通常最好使用两根完整的电缆，因为适配器可能笨重或容易丢失。您需要将包装箱中的内容与您的 PC 具有的特定端口（并具有免费端口）相匹配。您还需要匹配规格。如果仅具有支持 5Gbps 的端口，那么花额外的钱可能没有什么意义，例如，购买 10Gbps USB 3.2 Gen 2 SSD。
Many SSDs come with two types of cables (type A and type C) on the computer side, or one cable plus one adapter. It is usually best to use two complete cables as the adapter can be bulky or easily lost. You need to match the contents of the box to the specific port (and free port) your PC has. You also need to match the specifications. If you only have ports that support 5Gbps, it may not make sense to spend extra money, for example, to buy 10Gbps USB 3.2 Gen 2 SSD.
另外：不要将系统侧接口与将电缆连接到驱动器本身的连接器混淆。在某些便携式 SSD 上，SSD 末端的连接器是 USB Type-C 端口（与您在系统端可能看到的端口相同）
Also: do not confuse the system side interface with the connector that connects the cable to the drive itself. On some portable SSDs, the connector at the end of the SSD is a USB type-C port (the same port you might see on the system side)
但是，在其他端口上，该连接器可能是 Micro-USB Type-B，它是扁平的宽连接器，不同于您在笔记本电脑或台式机上看到的任何 USB 端口。
However, on other ports, the connector may be micro-USB type-B, which is a flat wide connector, unlike any USB port you see on a laptop or desktop.
需要坚固耐用吗？
Do you need to be strong and durable?
确实，如果您经常随身携带驱动器，则需要注意 驱动器的坚固程度。有些型号包括塑料保险杠，有些甚至达到 了防震和防尘的军事标准。寻找对 Ingress Protection 等级（例如 IP68）的支持，如上一链接所述。
Indeed, if you carry the drive with you frequently, you need to pay attention to the robustness of the drive. Some models include plastic bumpers, and some even meet military standards for shock and dust protection. Look for support for ingress protection levels, such as IP68, as described in the previous link.
当然，如果您随身携带驱动器，则希望它看起来不错。有些有多种颜色，而大多数则又小又纤细，足以塞进衬衫的口袋里。
Of course, if you have a drive with you, you want it to look good. Some come in many colors, while most are small and slim enough to fit into a shirt pocket.
也许您不需要太重的唯一事情就是保修。如果驱动器由于损坏而损坏，则保修可能不包括在内。即使驱动器由于制造缺陷而发生故障，大多数保证也只是更换驱动器而已，并不承担试图从设备中恢复数据的恢复服务的费用。长期保修是好的，但是驱动器
Maybe the only thing you don’t need to be too heavy is the warranty. If the drive is damaged due to damage, the warranty may not be included. Even if the drive fails due to a manufacturing defect, most of the warranty is just to replace the drive and does not bear the cost of recovery services trying to recover data from the device. Long term warranty is good, but drive
