What do you think? Is it a good idea to use a LaCie 1 TB SSD with Thunderbold connection as external system disk for my thick iMacs? (late 2009-mid 2011)
It depends on what year that you have.
Only the Mid 2011 iMacs have Thunderbolt, they were the first iMacs with Thunderbolt.
If you have the Late 2009 or Mid 2010 iMacs, your external options are USB2, FW800, and SD card.
There are other options, such as replacing the internal HDD and/or ODD with a SSD, and also add an internal SSD using the third, unused SATA port on the logic board. There are also USB3 and eSATA mods you can do. All of these involve opening the Mac with varying difficultly. Swapping the HDD and/or ODD for a SSD is the easiest and cheapest, some of the others involve removing the logic board.
Let us know exactly what iMac you have so we can better answer the question.
Also I could use it for the 2013 model, as I need an SSD but dont want to cut the glass loose.
The Late 2009 to Mid 2011 iMacs don't need to cut anything, the glass is magnetically attached, but you are right, the Late 2013 iMac does have the laminated display glued on.
Why? For not having the drive. Therefore I asked before buying one.
Whether it is worth it or not is debatable. It is one thing if you already had the equipment, then hell yes, it would be totally worth it, it is really a night and day difference.
But, if you don't already have the equipment, whether or not it would be worth it would depend on how how cheap you can get the drives and SSD for.
If you plan on using or older iMacs for a few years, then it could be worth it. Switching from a HDD to a SSD boot drive will give you a night and day difference, and feel like a totally different Mac.
This is even when using it over a slower bus like USB2 and FW800. The HDD will beat the USB2 and FW800 SSD when it comes to sequential speeds, like transferring files, but for everything else, like booting, opening opening file, opening apps, shutting down, the USB2 and FW800 SSD will feel a lot faster due to it having much faster Random speeds than the HDD.
But, if you don't plan on using your older Macs much longer, and plan on getting a new Mac soon, it wouldn't worth the investment on a TB SSD (for the Mid 2011 iMac).
Also, it is hard to find TB1 and TB2 SSDs. There are some TB2 SSDs on Amazon, and they have some decent read and write speeds, but they are pricing. I doubt you will find a new TB1 SSD.
You are better off going on eBay, and getting a used TB1/2 enclosure or external HDD and swap the HDD in the enclosure for an SSD.
Let us know what Mac you have.
