How To Set Memory Timings?

[PJ10]

Today while I was looking around in my bios I noticed my memory is set to 5-5-5-15 while it is suppose to be able to do 4-4-4-12.
I would like to change this but I had a couple of questions.
1. Do I need to have it set to 1T or 2T?
2. There are some other settings that I do not know what they are like tRRD tRC tWR tWTR and tREF, do I need to change these?
3. At 5-5-5-15 2T my voltage is 1.9v should I increase to 2.0-2.1v when I switch to 4-4-4-12?

Sorry for the dumb questions, I have never done this type of stuff and I don't want to screw anything up :P

BTW this is my memory:http://www.newegg.com/Product/Product.aspx?Item=N82E16820231148 and this is my mobo: http://www.newegg.com/Product/Product.aspx?Item=N82E16813188013

[maxfly]

1. you can try 1t but 2t will likely be more stable.
2. dont sweat the subtimings.leaving them on auto is fine for the most part.there are instances where you may need to adjust trc for stability but you likely wont need to worry about that.
3. it depends on the stock voltage of your modules.what exact model and brand are you running?

[PJ10]

Theres a link to the memory I have in my post, its G Skill 4-4-4-12 @ 2.0-2.1v

[Blazing fire]

If it's rated at that settings, why not :)

[SAnusha]

i use memset