SATA II SDD vs SATA III 5400 rpm, with configuration questions

[Happy Marshwiggle]

I have a Lenovo T420 running Windows 7, thus far stock, that I am looking to upgrade (as funds become available). The stock drive, as you might know, is a 320 gb 5400 rpm hdd in a SATA III (6Gb/s) bay. Replacement of this drive with an SSD would be a definite upgrade, for which purposes I am looking at the following:

http://www.newegg.com/Product/Product.aspx?Item=N82E16820104552

or even

http://www.newegg.com/Product/Product.aspx?Item=N82E16820226688

However, SSDs are expensive. The cost per gb is much, much higher than on a traditional hdd. I could get a 320 gb 7200 rpm Western Digital hdd for $60, as opposed to the 240 gb SSD for $99.
The loss of storage in switching over would be detrimental to some of the purposes I would like to use this laptop for (editing video - yes I know I'm slightly under-specs for a smooth experience, but it's what I have). In the way of more explanation, Windows 7 intself eats up an enormous amount of disc space, plus programs on top of that.
I've heard that a good configuration for this sort of thing would be to have one drive for system and programs, and another for storing data (originally, I heard that the system drive should be the fastest, but I'm not sure anymore). This lead me to look for more options, and I discovered the existence of an mSATA slot in my T420, rated at SATA II (3Ggb/s). This, of course, sent me to do more research, and I discovered the following:

http://www.newegg.com/Product/Product.aspx?Item=9SIA53D1JP6921

This item is rated at SATA III, but will be limited by the SATA II port.

And now, having presented possibly more information than you needed, I shall begin asking the questions:

1. How would the SATA II SSD compare to the stock drive in terms of speed? I was originally considering using this as a storage drive, but thought that, being of lower capacity (64-80 gb, reports said), I might use it as the boot drive. As such, I am wondering whether there would be a significant difference, considering the slower interface.

2. Considering it's large size, how would it stack up against a 7200 rpm drive in the SATA III bay?
I know the hdd would be larger, but I'm just talking speed.

3. Which would be the more sensible set up, considering? To boot off the slower drive and put my data on the faster drive, or to boot off the faster drive and put my data on the slower drive?

4. If the mSATA is faster than the stock drive, would it be necessary to upgrade to a SATA III SSD for data, or would a 7200 rpm upgrade work just as well?

5. The Kingston drive says that it has a quad-core controller to improve multitasking. Would this remove the bottleneck of trying to render to the same drive that you are pulling the data from? I'm not sure that would help a whole lot with my main question, I'm just curious on this one.

Any of the upgrades thus far mentioned would result in a faster computer. I'm just trying to learn more about the options that I think I have. In answer to the inevitable, "why not just spring for a 320 or 500 gb SSD," I will preemptively reply, "lack of available funds," or "budget."

Thanks for taking a look!

 

[Mattios]

1 - it would be faster, but obviously not as fast as your new SSD. Honestly if it used for data then a standard hard drive would be fine - that is what most people do - SSD for OS and HDD for data, because the data does not take long to load.
2 - a HDD barely saturates SATA I, let alone SATA III. The SSD would be faster.
3 - Boot off the faster drive, certainly. See my answer to question 1 of what most people do.
4 - HDD would be more than fine for data, save you money too
5 - Not sure really, I imagine this is mainly a gimmick and doesn't do much. I could be wrong. I suggest you further research this

If I were you - SSD for OS and HDD for data.

 

[LordConrad]

A SATA II SSD will still be much faster than a SATA III hard drive.

If you can wait a bit, save up for a 512GB SSD for your SATA III port. Samsung 850 EVO is a great deal and has a 5-year warranty.

If you can't wait, get the mSATA drive for booting and use your hard drive for apps and data.

 

[Happy Marshwiggle]

I apologize for not getting back to you all before now. I am traveling currently, and the internet has been spotty at best.

Thank you all very much for your advice!

Based on what you have presented to me, I will likely start with the mSATA (and the 7200 soon after), and then save up for a quality SSD eventually. I could use the mSATA at that point for a project/render drive. I've heard a lot of people saying good things about the Samsung EVO; I'll have to take a look!