PC1600 RAM unstable at rated speed?

[yiplong]

I have 2x2gb of PC1600 Ram from G.Skill, but they are only stable at 1333mhz. I called G.Skill and manually set the timing and HTT voltage as they told me, but the RAM still cannot run at 1600. Finally G.Skill tech told me that it is probably my CPU won't support memory at 1600.
My CPU is P2 X3 720, mobo is Gigabyte MA770T-UD3P. Does this make any sense? I thought the 720 supports DDR3 1600?

 

[Ikorolch]

You know what I am having the same problem, but I have an I7 920. I have Corsair Dominator PC3 12800 1600 8-8-8-24 and it is running very unstable. PC freezes sometimes, just froze when I just attempted to do the windows 7 performance test. I had a P2 x4 965 and it ran at 1600 8-8-8-24 no problem , just does not make any sense to me

 

[JDFan]

I've got a 720 using Crucial Ballistix DDR3 1800 Ram at 1600 speed @ 8-8-8-24-1T Timings and it runs fine at that speed ! (haven't OC'd the bus yet to get it to 1800 and x8 is the highest multiplier on my Gigabyte GA-MA790GPT-UD3H MOBO )- running with the 4th core unlocked and OC'd to 3.2GHz.

 

[saaiello]

OK OP your motherboard supports 1066 and 1333 DDR 3 and 1666 OC so really will only run 1333 and whatever you get above 1333 is OC so just get it as high as you can go and call it a day. Now since you are gonna run that ram slower you can tighten the timeings abit and that will make it run a little faster.