Problems with new memory

[yellams]

Hi all, I today received 8GB Ripjaws memory, it's currently running in my system. Prior to this I had 4gb running fine. I've looked at the manual and followed the pairing, but I'm unable to run both at the same time.
With all 4 modules in, the computer turns on, but doesn't beep (as normal) and the major issue is that no video is outputted, so I am unable to enter BIOS with all 4 in.
The two new modules have been through a diagnostic test and are perfectly fine, the 2 modules I had before hand are also fine and have been for 2+ years.
Bear in mind my motherboard can handle 16gb (M4A77TD PRO) I'm curious as to what the issue is, I can run them separately, so either 4gb or 8gb, but I am unable to have both pairs working simultaneously?
I am assuming this is due to BIOS settings for the 8gb set being better than the 4gb, but would like to clarify this before I start changing things.
Is a BIOS update a potential fix too?
Thanks.

 

[kromonox]

Is the 8gb Ripjaws memory one drr3 stick? if so i don't think ur mobo suports 8gb sticks. I would check asus' and check memory/device suport
http://www.asus.com/Motherboards/AMD_AM3/M4A77TD_PRO/#MSL

 

[alrobichaud]

Are you using 2x4GB and 2x2GB of RAM? If so, I don't think you can mix and match different size memory modules. Also, you would need to set the BIOS to the RAM with the slowest timings and the faster should default to the slower speed. Don't forget to make sure that both sets are the same voltage. Are both of these sets rated for the same speed?

 

[yellams]

The 8gb Ripjaws is 2x4gb and the original Crucial is 2x2gb.
In my old computer I was able to mix 2x512mb and 2x1gb (a long time ago) if that's what you're referring to regarding mixing and matching?
I believe both sets are 1600Mhz but don't have access to the order details for the original pair to clarify this. So if I lower the new and better ram to the same settings as the old pair, it should work?

 

[alrobichaud]

Like I said, I really don't know anything about your motherboard but I just read the manual and it says that you can use modules of varying sizes in channels A and B but it says that they need to have the same CAS latency. I believe your G.skill has a CAS latency of 9 at 1.5V. If your Crucial RAM is the Ballistix 4GB (2 x 2GB) 240-Pin DDR3 1600MHz then it has a CAS latency of 8 at 1.65V. Even if you lowered the crucial timings to 9/9/9/24 to match the G.skill one operates at 1.5V and the other at 1.65 V. You could try raising the G.skill voltage to match the crucial but I have no idea what damage if any this will cause.

 

[alrobichaud]

Also, you may need to make the nescessary BIOS changes with only one set installed and then install the second set and power up.

 

[yellams]

Ok, thank you for your help, I just realised the model number was on the stick itself, so the Crucial memory is CT25664BA1339.16FF, which is 240 Pin DDR3, I've just looked this up on Ebuyer and it seems it runs at 1333Mhz, not 1600Mhz like the Ripjaw (F3-12800CL9D-8GBXL) as they both seem to be running at 1.5V cl9. the other difference is the crucial is PC-10600 while the Ripjaw is PC-12800, so are they just incompatible together as a result of that difference?
Thanks again.

 

[alrobichaud]

i would think that you could still install both sets with your DRAM frequency set to 1333MHz and it should work.

 

[yellams]

Ok, I'll give that a try when I have a bit of time later today and I'll post back with the result.
Thanks for your help