TW3X4G1333C9DHX unstable on Asus M4A78T-E at stock vdimm

I understand this ram is rated for 1066@1.5 and 1333@1.6, but I have been unable to acheive stability at these settings.

a) All settings to Auto on M4A78T-E, ram set to 1066, vdimm reads 1.63, system is stable.

b) All settings to Auto on M4A78T-E, ram set to 1333, vdimm reads 1.92, system is stable.

But these voltages seem high (especially 1.92).

c) System is stable at 1066 with a minimum manual vdimm of 1.63 (any less crashes at windows boot)

d) System is stable at 1333 with a minimum manual vdimm of 1.8 (any less crashes within a couple minutes of prime95)

A couple of points here. The auto voltage settings on the Asus are alarming. That being said are my expectations of vdimm too low for these sticks? Are the sticks defective?

I have read elsewhere in the forum that this ram is covered by the warranty up to 2.0v, but are voltages this high potentially damaging to the motherboard and cpu? Intel says no vdimm over 1.5 for core-i7. Does such a restriction exist for am3?

Heat has not been an issue, and even at 1.8 the sticks do not feel more than slightly warm.

Thanks for any help.

Thanks for the quick reply.

Do you have any comments on the issue of higher vdimm and it's effect on the cpu that I raised?

Is it safe to assume that if heat is properly managed, vdimm up to 2.0v will not damage my ram, motherboard, or cpu?

Thanks.

The sticks are not the issue. The issue will be the AMD wonky memory controller. The voltages of the memory relate to the voltages on the memory controller (on cpu). If you move them too far apart, then the issues of stability will increase in the longer term even though they stabilize in the shorter term.

To put it bluntly, I find the AMD memory controller works far better with lower end speeds and high end speeds create issues in the longer term.

I believe that any voltages greater than 1.85v for the memory is not good for the memory or the memory controller, unless you raise the memory controller voltage controller.

I'm not sure this minimizing the difference makes sense considering the stock voltage on the cpu-nb is 1.325 and 1.5 for the dimms (leave alone the ddr2 case which is still 1.325 on nb and 1.8 on the dimms).

I have however heard it is good to keep the voltage diffence between the 2 voltage planes on the cpu (cpu-vid, and cpu-nb-vid) as close to each other as possible, but I can't find it actually documented anywhere.

Perhaps you are confusing these two ideas?

This is what I have found. I am not saying that you need to have the VID's identical.

I am saying that you need to play with these two voltages until you find the sweet spot between them.

And no, I am not confusing the two.

Good luck.

I'm not sure this minimizing the difference makes sense considering the stock voltage on the cpu-nb is 1.325 and 1.5 for the dimms (leave alone the ddr2 case which is still 1.325 on nb and 1.8 on the dimms).

 

I have however heard it is good to keep the voltage diffence between the 2 voltage planes on the cpu (cpu-vid, and cpu-nb-vid) as close to each other as possible, but I can't find it actually documented anywhere.

 

Perhaps you are confusing these two ideas?

Please see my specs...I'm building a new machine and getting BSODs whenever I put more than one stick of RAM in. The Vista disc gets just past the "Windows is loading files" progress bar and then BAM! If I only have one stick in I can get all the way to the point of installation (I cancelled after about 30% progress).

Are there custom BIOS settings I must input to make my 6 GB of RAM stable? This is my worst build experience ever. Thanks, Brian