Samsung R580 - adding RAM

I own Samsung R580 based on Core i3. At the moment it have 3GB DDR3, 2 chips - one 2GB and the other 1GB. I would like to take that 1GB chip out and put there 4GB.

Would such combination (4+2) is OK?

What RAM memory do I need to buy? Which one would be the best?

For what do I need to look for? Latency and frequency?

Is this memory a suitable one --> 4GB SODIMM DDR3 PC3-10600 1333 MHz?


I have 64-bit system.
Exact laptop model is NP-R580-JS0DPL so according to specification it can support up to 8GB of DDR3.
This information is written on a 2GB chip:

2GB 1Rx8 PC3-8500S-07-10-ZZZ
M471B5773CHS-CF8 1033

And this is how CPU-Z looks like:

 

I'm surprised no one's answered this given that the answer is pretty obvious with the details you've already posted.

According to your Samsung laptop model you have an Intel i3 370M processor? You can check this via downloading and running CPU-Z as you have done, it's the first tab.

All Intel mobile processors since 2010 have the memory controller on die. Given this, the processor specifies what RAM is suppoted. Once you know what i3 mobile processor you own you can check it's supported RAM specification at the following link:
What is the maximum capacity and type of memory supposed by my Intel i3 mobile processor based laptop?

I believe you'll find this to be 8GB and PC3-8500 which is otherwise known as DDR3 1066MHz.

Yes, you can install a 4 and 2GB SODIMM alongside each other but then you'll lose some performance when accessing the remaining 2GB. The first 4GB will run in syncrhonous dual channel mode while the remaining 2GB will run in single channel mode. You can read about this at the following link:
Synchronous and asynchronous dual channel mode on Intel flex memory supported laptops

I recommend you go with 2x 4GB for best performance. You can go and install PC3-10600 hence 1333MHz DDR3 but it will downclock to PC3-8500 speeds anyway. Given this there won't be any speed benefit from the higher frequency.