So how do youset DIMM timings, and why is it important?

purplefire

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Hi there, I was talking to a friend last night and he mentioned something about DIMM timings for ram. Apparently when you get new sticks you have to input the four-number sequence on the side of the sticks. Looks like i missed this, and boy is my face red.

So i got into the advanced part of the BIOS and put in the new 4-4-4-12, and then i put the refresh to ACT setting to max, as well as the write to precharge delay, as he told me to. The system becomes highly unstable. Either i get some weird sky blue screen when i lob in, or a blue screen after boot. When i launch ArmA2 i get a screen full of thin vertical bars that are dark grey and light grey. I have a HD5870 and i've only seen these screens with this new card.

So is it even worth setting these timings, and is there a performance gain? He seems to think it would be substantial. Can i make them stable?

Thanks for any advice!
 
What motherboard and memory? Did your friend forget to tell you that RAM voltage also is important and that it has to be set correctly if you don't use the default timings (JEDEC) values? Using tighter timings will not make a huge difference, but performance might increase by up to 1-2 % in some games.
 

roonj

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Just in case this is a little too technical at this point, go back and set everything to Auto and get the system running again.
Then just look at what settings its using and compare these to what the memory chips say.
Commonly 4-4-4-12 is a high quality DDR2-6400 memory module. To achieve this the voltage is usually higher than what auto selects.
Your new memory which I guess is all your using should say on the package what voltage it requires to use these higher settings.
While you don't say what board your using some have an enhanced memory feature which can set the voltage and timings based on what the chips say when enabled. You need to go look and report back.
 

purplefire

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Sorry should have been more specific. I have four sticks of 1Gig quad channel black dragon ram, from GeIL. I'm unsure where the packaging is as i've had them for ages. The motherboard is a GA-P35-DS3L
 

purplefire

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Sorry, where do you set that? Is it the CPU VCore voltage? As that's the only one capable of going to 2.000v. DDR2 only goes up to something like 0.6v, and even then it's red and flashing like i shouldn't ever touch it.

Is increasing voltage dangerous? I understand there are overclocking risks most of the time, but playing with voltage seems a bit dodge.

Thanks for the help!
 

Not necessarily. Sometimes, you can run a motherboard with all DIMMS without increasing voltage. If you're running standard JEDEC timings, you should always be able to. I'm running all 6 slots full on my i7 with memory voltage below stock (and timings tighter than stock). It's true that running 4 DIMMS increases the load on the memory controller, but if it's stable at 1.8V, there's no reason to increase it.

Purplefire: it sounds like your BIOS setting is the additional voltage over stock. Since the standard is 1.8V, to get 2.0 V, you would need to add another 0.2. This would be a setting of 0.2 in the BIOS. 0.6 up from stock would give you 2.4V, which is quite high (and it is understandable that it would be flashing at you if you were trying to select this).