AMD Athlon II P320 memory controller speed

Note that 533x2=1066. You are already at the max and are good to go.

Have fun!

I have 600MHz memory at the moment. CPUZ shows it works at speed of 533. Manufacturer says that I can put up to 1333, but it works at max speed of 1066. However, memory controller speed is 533. Is there any good for me to buy 1066 memory?

Sorry I'm not so good explaining these things  

600Mhz x2 = 1200 max so it won't work at 1333 reliably, but can at 1066. Sounds like you are already running at 1066. Increases is speed only have marginal impact increasing performance. You really don't need to do anything as your system is working properly.

I never knew that memory where is writtern 600MHz can work at 1200MHz  

DDR = Double Data Rate therefor the multiplier. Happy new year!

Not exactly, the RAM works off multipliers in the BIOS. The analogies are intriguing but not correct. In order to set the RAM speed correctly you'll need to go into the BIOS and set the proper DRAM Frequency. In 'most cases' 1066 MHz is the default speed and there's no need to manually set the DRAM Frequency. If the OP has 1333 MHz or faster then yes you'd need to adjust in most cases...

Yes, there's an advantage to 1066 over 'something' less, but the difference is NOT as much as most people think; differences with the same CAS & same IC's from 1066 -> 1333 MHz is 1~3%.

Yes, what CPUz shows is the 'true' speed, but doesn't show the DDR {Double Data Rate} of the RAM; DDR allows the RAM to process at both the top and bottom of the Sine wave - hence double data rate per clock cycle. So 1066 MHz RAM will show up in the JEDEC #4 as ~533 MHz.

Please post both the exact 'Laptop' and 'RAM' used.