I'm thinking of getting a bigger HDD 2 or 3 TB as my GOG collection is at 600GB (windows installers & extras).
I do have a 1TB external but i'm thinking of the future & i thought what benefits do Internal or external offer.

If you need to move the HDD around a lot and don't have hotswappable hdd bay, i suggest buying an external.

If you don't need to move it around, buy an internal. Sata is faster than usb. Or if you have an eSATA port use it with an external HDD


For more reading: http://hothardware.com/news/usb-30-and-sata-6g-performance-preview

Edit: remembered eSATA

I have all my 1148 GOG games (English Windows installers + extras) on an external 2TB USB drive (2.5"). It is USB-powered, so it is easy to connect to any of the PCs I might want to install some GOG game.

Internal if you want to run the drive all day. A lot of externals have poor air flow and excessive heat can lead to a drive's early demise if used heavily. Externals however, are great for backing up a laptop or for sneakernet purposes.

Internal, every day. Buy a HDD caddy, I have two of these:
http://www.novatech.co.uk/products/components/harddrives-external/harddriveenclosures/IcyDock/MB971SP-B.html?gclid=CIKexsjeuskCFdQ_GwodZIYEsw#utm_source=google&utm_medium=base&utm_campaign=products

In my machine, all the HDD's are placed in there. I have four other 4tb HDD's, which each three months I plug one in, copy the internal HDD over, and remove.

External HDD's are useful if you are travelling as the bits aren't exposed, however for home backup purposes, uncased HDD's swappable, and also make sure to buy storage case:
http://www.amazon.co.uk/SATA-Anti-Static-Storage-Tank-Case/dp/B003OBZQUQ
For instance will do you fine. You have maximum speed of transfer (useful with large amounts of data), and easy to store, plus price wise, externals seem to be dearer per MB and I have heard *rumours* that the quality in external drives tends to be quite low. I have had a fair few external's over the years and after a while they get too small and lose purpose, at least with HDD's you can plug them all into a server or NAS dock and RAID combine them later on to be useful.

The rumors may even be true. Some time ago 2 HDD manufacturers used refurbs to make external HDD-s

And some HDD-s, I'm looking at you Toshiba, use some very bad solder inside the casing, have had to solder some HDD-s over to rescue my data (yeah, I don't have my Icy box anymore ;()

Thanks for the suggestions guys. it'll be a backup for GOG games,music,photos.ect. I only plug them into update & transfer files & unplug them when i'm finished.

^This. I've had two external drives die on me, probably from excessive use (and children and cat...). Another option would be a NAS. Those usually have better cooling and in some corner they can run all day. And you can use your installers (and photos, videos, music...) on all the computers in your household.

The disadvantage is of course that it's fiddly to carry them around since they're bigger than external drives and most require a network connection (instead of simply plugging them to USB). Also data transfer isn't as fast over network as USB3 or eSATA.

I like laptop sized external HDDs for backup, they seem to be more reliable though a bit more expensive.

It sounds like heat won't be an issue for you then. I think an external would be ideal for your purposes. :)