我最近从Synology购买了(Synology)NAS（网络附加存储）设备，将其连接到我的网络并开始传输文件。我注意到的第一件事是网络传输速度(network transfer speed)有多慢。
我正在复制一些大型视频文件，这需要很长时间！我决定检查我的NAS 和 PC(NAS and PC)之间的传输速度(transfer speed)，以查看数据传输的速率。
我下载了一个叫做LAN Speed Test的程序，它得到了一些很好的评价，并尝试了它。果然，我的下载速度(download speed)不到40MB/s！请注意，这是每秒兆字节，而不是每秒兆比特。我将详细介绍Mbps 与(Mbps vs) MBps以及所有这些技术内容。
经过一番研究，我发现自己做错了什么，最终将传输速率提高到了(transfer rate)85(speedy 85) MB/s的超高速MB/s upload和 110 MB/s download！从技术上讲，只有使用千兆以太网(Gigabit Ethernet)才能获得这种速度。
如果您有 10 Gigabit 以太网(Gigabit Ethernet)，那么理论上您可以将上传和下载速度(upload and download speed)提高 10 倍。我也会在下面解释更多。
LAN 数据速率单位
首先，让我们弄清楚数字。有标准的 100 Mbps 以太网(Mbps ethernet)，这是大多数人在家中使用的。100 Mbps是每秒 100兆比特(megabits)。这转换为每秒 12.5 兆字节（MBps or MB/s）。转换为MB(MBs)要容易得多，因为这是我们都熟悉的东西，而不是比特。
这意味着，如果您的计算机或NAS上没有千兆路由器或交换机(gigabit router or switch)和千兆网卡(gigabit network card)，则您能够通过家庭网络(home network)传输文件的最大速度为 12.5 MBps。
此外，在现实世界中，实际上不可能达到理论上的最大值。您最终可能会达到 4 到 8 MBps左右。如果你得到的东西非常低，比如 1 MBps或更低，我将在下面提到原因。
请注意，即使您的计算机有千兆以太网卡，除非所有传输数据的设备都支持千兆(support gigabit)，否则您将无法获得更高的传输速度。
如果您的计算机上有一个千兆以太网卡，您的路由器或交换机(router or switch)是千兆的，并且接收设备(receiving device)也有一个千兆以太网卡，那么您的最大传输速度(max transfer speed)会跳到更好的 1000 Mbps或 125 MBps（125 兆字节每秒）。
同样，您不会获得理论上的速度，但您应该获得 70 到 115 MBps的速度，具体取决于您传输的文件类型和网络设置(network setup)。
最后，最新的设备可以升级为 10GBe 网卡。当然，您需要一个也可以处理 10GBe 的交换机，但从图表中可以看出，传输速度(transfer speed)比大多数人现在使用的速度快 10 倍。
如果您正在处理大量需要通过网络传输的视频文件，那么升级硬件将大大改善您的工作流程。幸运的是，Cat5e 电缆(Cat5e cable)可以在较短的距离上处理 10GBe。如果您需要铺设新的电缆，它应该是Cat 6a或Cat 7。
传输速度取决于什么？
因此，正如我们上面提到的，网络传输速度(network transfer speed)取决于您网络上的以太网类型，但这不是唯一的因素。还有其他几个因素决定了您在两台设备之间的最终传输速度。(transfer speed)
硬盘速度
一个主要的限制因素是硬盘驱动器的速度(drive speed)。如果您有一台 5400 RPM的计算机，那么您的传输速率(transfer rate)将比在RAID 0配置中拥有两个(RAID 0)SSD驱动器时慢很多！为何如此？这得看情况。
在我的网络上，即使使用千兆以太网(gigabit ethernet)，使用传统盘片硬盘时，我也只能获得大约 40 到 50 MB/s
如果您在线阅读，您会发现即使是大多数硬盘驱动器（SATA 3.0 GB/sMB/s的读取速度达到最大值。这意味着如果不使用更昂贵的配置（如RAID 0,1(RAID 0,1)或 5 与实际硬件RAID控制器），您甚至无法超越这一点。
当您跳上SSD时，事情会变得更快。但是，要获得我在顶部向您展示的结果（接近 110 MB/s），您很可能需要一个超快的NVMe SSD 驱动器(NVMe SSD drive)。这些驱动器的读写速度高达 3000 MB/s，远远超过千兆以太网(Gigabit Ethernet)。
巴士速度
即使你有一个快速的硬盘驱动器，数据仍然必须从硬盘驱动器传输到你的主板，然后再传输到网卡(network card)。公共汽车(bus speed)的速度有很大的不同。
例如，如果您使用较旧的PCI 总线(PCI bus)，则数据传输速率(transfer rate)仅为 133 MB/s。这听起来可能比千兆以太网(gigabit ethernet)的最大速度要高，但总线是在整个系统(whole system)中共享的，所以你永远不会真正得到那个速度。
最新的PCI Express 版本(PCI Express version)可以让您获得最高 985 MB/s，因此会有很大的不同。这基本上意味着，如果您尝试从一台非常旧的计算机传输文件，并且即使您购买了千兆以太网卡，也不要期望获得接近最大 125 (max 125) MB/s transfer速率。
网线
所有这一切的另一个方面是布线。如果您的电缆较旧或靠近电源，则可能会影响性能。此外，如果电缆很长，长度也会有所不同。
然而，总的来说，这不会有太大的不同，所以不要出去开始更换所有的电缆。您基本上要确保您有 CAT 5e 或CAT 6a/7电缆。
从这里得到的主要观点是，硬盘驱动器是一个主要的限制因素，也是您只能看到 30 到 80 MB/s结果的最可能原因。要获得真正高的数字，您需要 RAID 0(need RAID 0)用于传统硬盘驱动器，NVMe用于SSD(SSDs)或 10GBe 设备。
网络设备
最后，您应该尽量让您的两台机器（NAS 和 PC(NAS and PC)）连接到同一个交换机或路由器(switch or router)。我将我的计算机和 NAS(computer and NAS)插入同一个交换机，然后将我的交换机连接到无线路由器(wireless router)。
大多数路由器也是交换机，从技术上讲，您应该获得与专用交换机相同的速度。但是，根据我的经验，Netgear 或 Cisco(Netgear or Cisco)的专用交换机总是比具有内置端口的无线路由器性能更好。
其次，如果您从PC 或笔记本电脑(PC or laptop)通过WiFi连接，您将无法获得快速的速度。您必须确保使用以太网端口(Ethernet port)以获得尽可能快的速度。
文件大小
我还注意到传输大量小文件比传输较少的大文件要慢。例如，当在一堆目录中传输数千张照片时，我将获得大约 20 到 60 MB/s transferGB(GBs)大小的大型电影文件将产生更快的 100 MB/s+。
结论
希望这篇文章能让您更好地了解影响LAN网络传输速度(network transfer speed)的因素。这从来都不是我之前真正关心的问题，但是在我拥有一台 4K摄像机(video camera)之后，我不得不购买NAS来管理所有额外的数据。
真正缓慢的传输速率让我分析了我的网络，一路上我学到了很多东西。即使您现在不太关心(t care)您的传输速度，但在未来的某个时候，它可能会突然产生重大影响。
在评论中让我们知道您的想法。您在LAN上获得什么样的速度？享受！
Understanding LAN Network Data Transfer Speeds
I recently bought a NAS (network attached storage) device from Synology, connected it up to my network and ѕtarted tranѕferring files. The first thing I notiсed was how ѕlow the network transfer speed was.
I was copying over some large video files and it was taking forever! I decided to check the transfer speed between my NAS and PC to see the rate of the data transfer.
I downloaded a program called LAN Speed Test, which had gotten some excellent reviews, and tried it out. Sure enough, my download speed was less than 40 MB/s! Note that is megabytes per second, not megabits per second. I’ll go into more detail on Mbps vs MBps and all that technical stuff.
After doing some research, I figured out what I was doing wrong and eventually got the transfer rate up to a super speedy 85 MB/s upload and 110 MB/s download! Technically, you can only get that speed if you’re using Gigabit Ethernet.
If you have 10 Gigabit Ethernet, then you could theoretically be getting a whopping 10 times faster upload and download speed. I’ll explain more about that below too.
LAN Data Rate Units
First, let’s get the numbers clear. There is standard 100 Mbps ethernet, which is what most people have at home. 100 Mbps is 100 megabits per second. That is translated into 12.5 megabytes per second (MBps or MB/s). It’s much easier to convert to MBs since that is something we are all familiar with rather than bits.
This means that if you don’t have a gigabit router or switch and gigabit network card on your computers or NAS, the maximum speed you’ll be able to transfer a file across your home network is 12.5 MBps.
Also, in the real world, it’s impossible to actually get that theoretical maximum. You’ll probably end up somewhere around 4 to 8 MBps. If you are getting something really low like 1 MBps or less, there are reasons for that which I will mention below.
Note that even if your computer has a gigabit ethernet card, you won’t get those higher transfer speeds unless all the devices that the data is being transmitted through support gigabit.
If you have a gigabit ethernet card on your computer, your router or switch is gigabit and the receiving device also has a gigabit ethernet card, your max transfer speed jumps to a much better 1000 Mbps or 125 MBps (125 megabytes per second).
Again, you won’t get that theoretical speed, but you should be getting anywhere from 70 to 115 MBps depending on the type of files you are transferring and your network setup.
Finally, the latest devices are upgradeable with 10GBe network cards. You’ll, of course, need a switch that can also handle 10GBe, but as you can see from the chart, the transfer speed is 10 times faster than what most people use right now.
If you’re working with a ton of video files that need to be transferred over the network, upgrading your hardware will greatly improve your workflow. Luckily, Cat5e cable can handle 10GBe over shorter distances. If you need to lay down new cabling, it should be Cat 6a or Cat 7.
Transfer Speed Depends on What?
So as we mentioned above, network transfer speed depends on the type of ethernet you have on your network, but that’s not the only factor. There are several other factors that determine your final transfer speed between two devices.
Hard Drive Speed
One major limiting factor is the hard drive speed. If you have a computer with a 5400 RPM, your transfer rate will be a lot slower than if you have two SSD drives in a RAID 0 configuration! How so? Well, it depends.
On my network, even with gigabit ethernet, I only get around 40 to 50 MB/s when using a traditional platter hard drive.
If you read online, you’ll find that even most hard drives (SATA 3.0 GB/s) will max out at a read speed of 75 MB/s. That means you won’t even be able to past that without going to more expensive configurations like RAID 0,1, or 5 with actual hardware RAID controllers.
When you jump up to an SSD, then things will get faster. However, to get the results I showed you at the top (close to 110 MB/s), you most likely need to have a super-fast NVMe SSD drive. These drives can read and write up to 3000 MB/s, which is well beyond Gigabit Ethernet.
Bus Speed
Even if you have a fast hard drive, the data still has to transfer from the hard drive to your motherboard and then to the network card. The bus speed makes a big difference.
For example, if you are using an older PCI bus, the data transfer rate is only 133 MB/s. That may sound higher than the maximum for gigabit ethernet and it is, but the bus is shared across the whole system, so you never really get that speed.
The latest PCI Express version will get you a max of 985 MB/s, so that makes a huge difference. This basically means if you’re trying to transfer files from a really old computer and even if you buy a gigabit ethernet card, don’t expect to be getting anywhere near the max 125 MB/s transfer rate.
Network Cables
Another aspect to all of this is the cabling. If your cables are old or if they are close to power sources, it could affect performance. Also, the length will make a difference if the cables are very long.
Overall, however, this is not going to make huge difference, so don’t go out and start replacing all your cables. You basically want to make sure you have CAT 5e or CAT 6a/7 cables.
The major point to get from here is that the hard drive is a major limiting factor and is the most likely reason you will only see results range from 30 to 80 MB/s. To get really high numbers, you’ll need RAID 0 for traditional hard drives, NVMe for SSDs or 10GBe devices.
Network Devices
Lastly, you should try to keep your two machines (NAS and PC) connected to the same switch or router. I plug my computer and NAS into the same switch and then connect my switch to the wireless router.
Most routers are also switches and technically you should get the same speeds as a dedicated switch. However, in my experience, a dedicated switch from Netgear or Cisco always tends to perform better than a wireless router that has built-in ports.
Secondly, you won’t get fast speeds if you are connecting via WiFi from your PC or laptop. You have to make sure you are using the Ethernet port to get the fastest speed possible.
File Size
I have also noticed that transferring a ton of small files is slower than transferring fewer larger files. For example, when transferring thousands of photos in a bunch of directories, I would get around 20 to 60 MB/s transfer rate whereas transferring large movie files several GBs in size would yield a faster 100 MB/s+.
Conclusion
Hopefully this post gives you a better understanding of what affects the network transfer speed on your LAN. This was never really an issue I cared about much before, but after I got an 4K video camera, I was forced to buy a NAS in order to manage all that extra data.
The really slow transfer rates got me analyzing my network and I learned a lot along the way. Even if you don’t care much about your transfer speeds right now, there may be a time in the future where it will suddenly make a big difference.
Let us know your thoughts in the comments. What kind of speed do you get on your LAN? Enjoy!
