I am new to this forum and hope that someone can help me as I can't seem to get any help from other forums on this problem.
First I have a Asus P5B deluxe board with the latest bios installed (1232) Windows Vista 64bit SP1, CPU Quad Core 9650 1333FSB
The problem is that I just installed 8gig of Twin2x4096-8500C5DF 1066mhz Corsair Dominator ram with Fan.
I was told to run it at 5-5-5-15 2T 1000mhz with 2.15v as the dram freq only gives me the options of 667,833,1000,1111,1333.
It will boot at this and run Vista no problems, when I run memtest I get errors every where, same when I run vista 64bit mem test
I get errors, By the way all the voltages are on Auto except Ram which is 2.15v,
Now I went back into the bios and set the dram freq to 833mhz and the timings on the ram to 4-4-4-12 2T and have no problems at all, memtest no errors, windows memtest no errors, runs stable, My question is why cant I run it at 1000mhz and 5-5-5-15 2T?
The mother board is suppose to support 1066mhz OC, How would I get it to run at 5-5-5-15 2T (1000mhz which is below the ram specs and the boards) Please help I have tried everything with this, I am new to OCing as well.
Some one must know out there........
When you do this, please remember that makers (both Mobo and RAM) often presume a 2 DIMM setup, and their timings/voltages are developed with that in mind. Therefore, when you double up these may or may not be adequate. So you potentially could end up having to play with it to get it all to work.
I recommend manually set all timings to the manufacturer's certified. Manually set tRFC to 54 or greater, and ensure the command rate is set to 2T.
If there's an issue, then manually set the voltages to the max (or near max) of the manufacturer's rating for the modules you have installed. Should be 2.1v~ish. If that works, stress test, then consider dropping a 10th at a time. Slightest sign on instability, bump it back a 10th. Do Not Over Volt your RAM.
If that doesn't work, the next step would be to bump the voltage to the North Bridge by one setting, and try again. So if the NB voltage is 1.3 then bump it to 1.31, or whatever the next higher setting is.
If that still doesn't work, then relax your timings a notch: For example, if your RAM is 4-4-4-12, then change to 5-5-5-15. Try again.
It's possible you'd need to try a couple combinations. But from what I've seen, on quality components, you're looking at a 10th or 100th of a volt here, and a tweak there. You should not need to make big changes, rather small ones to find a working setup.
In my case, I have 8GB of 800 Mhz OCZ Reapers 12 hours Prime 95 Blend stable at 4-4-4-12, 2T, 2.05volts. tRFC is 54. FSB is set to 1.33. There was no need to loosen timings on my setup. Rig details in siggy
thanks Scotteq, I already have the system stable at 4-4-4-12 2T at 833mhz, I just want to get it at 5-5-5-15 2T 1000mhz, This is what I am having the problems with in memtest ect, The system boots ok with these settings just get memtest errors and Vista mem test erros as well.
I have decided to put in a gigabyte GA-X48-DQ6 with the new X48 intel chipset, the P5B Deluxe with the 965 chipset is getting a bit old now, Thanks for all the help though, Also I did try all this with no luck..
The max tRFC that you can set from the bios on the P5b-D is 42, that is probably the issue. It might be possible to flash the spd of you dimms to a higher tRFC but I have seen no confirmed results of this anywhere for this mobo.