Need some advice please. I've been running my system based on the below specs (minus 6gb of ram that I just added) without any issues for the last 6mo. Yesterday, I added an add'l 6 gb of ram to my MB and now my vid cards are not working when both are installed (SLI enabled or not). When I boot to windows, my video cards are recognized in device mgr as being present, but the vid hardware is not being used (there is an exclamation next to each card in device mgr. So, basically the symptom is that the default windows resolution of 640x480 is being used and cannot be changed.
When I have 12gb or ram installed with only 1 vid card installed, all works well. Same if I remove the add'l 6gb of ram and reinstall both vid cards (as was previoulsy set up).
I'm thinking my PSU could be an issue here as it is a little light? But, before I start buying new hardware, I wanted to see if anyone had any thoughts or suggestions?
Sounds like you have two issues; first the RAM issue:
It's always a good idea to work your way up to an overclock....
If you CHANGE hardware you have to do it again. SO, put the CPU & RAM back to normal clocks, voltages, and timings.... and let us know.
I've heard many, many times you can OC your RAM to 1600 with 3 sticks but bump up t 6 sticks and it doesn't work....
Second issue; WELL ENOUGH OF THE FINE POINTS, you need more power too:
A good rule of thumb is: 650 watts will run almost any SINGLE card..
and 850 watts will run almost any DUAL card setup...
I love the Corsair 850HX supplies because they remain dead silent to almost 600watts...
What is the OS? I've been told that the RAM on the video cards plus the MB ram counts towards the total ram that the OS can handle. Have you with the new ram gone over the amount that you OS can handle?
@Traildriver - I'm running W7 64 bit so there is no issue with max memory limitations.
@jb6684 - You are right on the money with your analysis! I've dialed back my overclock as you suggested and I'm able to run w/ all 12gb at stock speeds (cpu and memory). I will continue to tweak this, but at the moment I'm stable at 3.5ghz with the ram dialed back to 1552. Before adding the ram, I was stable at 3.83/1660.
Not sure if this is a good trade off; sacrafice cpu speed for more ram?