Using DDR2 RAMs with different frequencies

[-:cHiNmAy:-]

Hey guys i need your help.
I have AMD Athlon X2 250 and gigabyte motherboard with 2GB DDR2 800Mhz RAM currently installed. I got a 1GB DDR2 667Mhz RAM. Will it be ok if i install both RAMs with different frequencies?
Will it affect the performance?

[T.J.]

You should know that RAM are backward compatible so if you run a 800mhz ram with a 667mhz ram, then both will work on the 667mhz frequencies because ram's always work at the lowest stick frequency. However, if both will not sync between the RAM modules then it will screw up your system. So, its better to run ram that have same frequencies.