External Drive Talk

External hard drives are a very useful tool in your arsenal of PC peripherals.  They are useful for hosting your backup files (See Backup, Backup, BACKUP!) and when your main PC drive is starting to run out of space.  Certain types of external drives can be used for central storage of your music and/or family photos.

There are two types of external drive connections.  One type is via USB, SATA or Firewire, where basically the drive is connected directly to your PC, while the other type is via ethernet or wireless connection to your internal home network. 

If you connect a USB drive to your computer, you can expect theoretical speeds at 12Mbps with USB 1.1 and 480Mbps with USB 2.0.  Firewire is rated 786 Mbps (Firewire 800) theoretical.  SATA can get you much higher data speeds, which can go higher than 1.5Gbps.  Again, all these are theoretical rates, actual rates are affected by many factors - even temperature!  But again, these types of connections are just direct to your computer alone.

If you read my previous blog Kilo, Mega or Giga Speed, you'll get an idea about Internet connection speed.  Internet connection speed is typically slower than local network speed.  Most of today's PC's have Gigabit speed ethernet cards built-in, and therefore you can assume connection speeds at 1Gbps theoretical.  What you get actually is affected by the same factors affecting Internet connection speed. 

Connecting an external drive to your local network is very useful because you can share music files, photos, and other files with all the other computers on your network.  Contrasting that with a directly connected external drive you get sole use of the drive.  Each type of drive connection has it's place. 

At the request of a relative, I want to focus a little on a network connected external drive.  No matter which type you get, you want to remember the old addage, "A chain is only as strong as it's weakest link".  Or, by changing the words a little bit, "Your network speed is only as fast as the slowest device."  Lets say you have a Gigabit speed network card built in to your PC, and you went out and bought a discounted network external drive that has only a 100Mbps network connection.  You've effectively slowed down your network by connecting a slower device.  Many consumer grade wireless routers do not have Gigabit ethernet connectors simply because at the time of this writing, you can't get wireless speeds to go that fast, nor can you get (home) Internet speeds that fast.  So there isn't a need to put Gigabit speed ethernet ports on the wireless router.  So if you use your wireless router as the main point of connection between your PC and the external drive, and the wireless router has 100Mbps ethernet ports, then you are limiting the speed which you can write and read your data from the drive. 

Here's what I do.  I use what is called a Gigabit network switch.  You can purchase multiple port Gigabit switches which you can use to connect all your internal network devices.  Forgive the cheesy illustration, but this is basically how I have my network. 

Connect the Gigabit switch to all of your internal devices and then to the router/firewall.  Be aware, that if you are going to try to access files from the network attached external drive over a wireless connection, you have to think about the old addage I wrote about above.  At the time of this writing, gigabit speeds over (home) wireless devices has not yet been attained, so your wireless connection will be the "weakest link" when you are trying to copy files to or from the external drive.  Just to give you an idea, wireless connections can range from 11Mbps to above 54Mbps depending on what type of wireless protocol is being used by your wireless router and wireless network card in your PC.

With this information, I hope you are able to build your own little digital home empire!