Will 1066, 1333, 1666 mobo support 1600 memory?

Yep, it'll work.

However, some modules might require higher than normal voltages, like 1.65V instead of the usual 1.5V. If you set the RAM to "Auto" or something similar, it might run at 1333 MHz instead of its rated 1600. If you want it to run faster, you will have to set it manually in the BIOS.

However, if it runs at 1600 MHz by default, then your motherboard will choose the settings automatically.

To get it to run at 1600 you'll need to go into the BIOS and set the Timings and memory speed and possibly the Voltage so that it runs at the rated speed - the default speed is 1333 so when you first boot it will set it to that speed and you need to switch it manually in the BIOS to increase that but it is very easy to do. (And the Gigabyte MOBO's make the process fairly foolproof (if for some reason you set it wrong and the MOBO can not start it will reset things back to default so you can try again !!)

If you haven't bought the RAM yet I'd suggest looking for some better timings usually for about the same price you can find some with a CL of 7 or 8 which will run faster than the CL9s that you mention so look around before buying !

okay, thanks for answering  
i'll see what else i can find that can be shipped to my country..
not sure how to set these timings and voltage yet, but i'll do some research  

okay i think i found something
OCZ 4096MB Memory Kits (2x2048MB) PC3-12800 1600 MHz DDR3 Unbuffered CL7 DIMM Reaper HPC Edition
Memory Size: 4096MB (2 module(s) x 2048MB)
Memory Type: DDR3
Memory Speed: 1600MHz
Memory Package: DIMM
Designation: PC3­12800
Pin Configuration: 240 pins
Bus I/O Configuration: Unbuffered
CAS Latency: CL 7­7­7­24
1.9 volts

I don't think you'll want that. 1.9 volts is way, way beyond Intel's recommended 1.65 volts maximum RAM voltage. Try to look for something that is 1.65 volts or lower. I'm pretty sure there are CL7 and CL8 kits that work at 1.65 volts, although they might be more expensive.

Now look at what you wrote and compare to what he is using. AMD, amd's memory controller can handle 2.2v+

That is correct - the RAM that he linked is designed for AMD MOBO's which can support much higher Voltage than Intels - so those would be good with the 7-7-7-20 timings they are much better than the CAS 9 modules listed earlier !

okay thanks for answers!
so 1.9v ddr3 should run fine with this gigabyte mobo and amd 965..
i still have to set some timings and voltage in bios right?
if yes, then can you add some good link how to do it  
i don't usually touch stuff in my pc bios..

Oh god, now I'm feeling like an ubernoobie.  )

I misread the first post.

Still, I stand by my suggestion that nothing above 1.65 V should be used. Other than the fact that it will use more electricity, the same performance could already be achieved with lower-voltage modules.

I'd disagree with you there - I've got some DDR3 1800 modules that are rated at 1.9V 8-8-8-24 (they were cheaper than the 1600 rated modules at the time of purchase) and they are currently running just fine at DDR3 1600 8-8-8-24 1T @1.7V (since my MOBO only supports 1600 unless I increase the bus speed and haven't done that yet !) and still seem to have more headroom for when I begin to overclock this system more aggressively (and being Rated to run at 1.9V I know I can still add more Voltage and not risk burning them out since they are rated to run at that higher voltage (so if they do burn out at 1.9Volts I can send them back under the warranty where if I put 1.9Volts into a 1.5 or 1.65V rated module I would be assuming the risk of putting that much more Voltage than they were rated for into them. For an AMD system the higher Voltage rated modules are fine it is just that Intel MOBO's will burn up the Dimm slot if you run them much over 1.65V so you would not want to use a 1.9V rated module on on of those MOBO's.