ram frequency compatibility issue

Solution
You can, but there's no guarantee it will work. The system is supposed to just downgrade the faster stick of RAM to match the slower one, but sometimes it can't make them both stable.

If the voltages for the two sticks are different, it's very unlikely they'll work together.

In my experience, probably 3 out of 4 times this works but doesn't give you any performance increase ... the other 1 out of 4 it will be unstable and either fail to boot or cause random crashes.

The only time when this would help is if your system was being bottlenecked by having a very small amount of RAM, like 1GB or 2GB, and the extra capacity made a big difference.
You can, but there's no guarantee it will work. The system is supposed to just downgrade the faster stick of RAM to match the slower one, but sometimes it can't make them both stable.

If the voltages for the two sticks are different, it's very unlikely they'll work together.

In my experience, probably 3 out of 4 times this works but doesn't give you any performance increase ... the other 1 out of 4 it will be unstable and either fail to boot or cause random crashes.

The only time when this would help is if your system was being bottlenecked by having a very small amount of RAM, like 1GB or 2GB, and the extra capacity made a big difference.
 
Solution