hi i got a athlon x4 620 that i have found to be stable at 3.30Ghz and at that speed my ram runs at stock of 1333Mhz, but i have also found that 3.8Ghz on my cpu is stable but then my ram runs at about 1000Ghz (took a guess, cant remember). Does the extra Ghz on the cpu make up for the lower Ram speed? and ocing my ram is a no go since im running kingston value ram.
i mainly play games and still running a low res where cpu's make a difference.
Even if you cannot overclock you ram you should be able to balance it out with latency and ratio.
What are your ram settings according to CPU-z?
Are your RAM options set to auto?
To answer your question, lower mhz(ram) is fine, but you'll need to tighten the timings to make up for it. Slower ram usually doesn't hurt performance too bad, however very slow ram can hurt it greatly.