Memory readings in CPU-z are listed in two seperate columns. The second column shows my current settings of 5-5-5-15, which are manually set in the bios. The 1st coumn lists 4-4-4-12. Any idea what those are?
Seems from what I've read that they're the actual timings out of the box. But unless they sent me the wrong ram, it should be 5-5-5-15. Any idea?
don't the 2 columns show the reading for different Front Bus Speeds?
I think so. I'll have to check when I get home tonight. Regardless, I have them manually set to 5-5-5-15. Wouldn't think it would matter the FSB if they're manually set. May see if I can tighten the timings and keep it stable. Memory definitely isn't my forte.
The 4-4-4-12 timings show for 266, like 31 mentioned. Why is that? The memory is rated at 5-5-5-15. I'm tempted to set FSB back to default, and let the memory run on auto to see what CPU-z reads it at.
Or can someone clarify for me so I don't have to jack with it?
Anyone think I'd be able to tighten the timings on this ram and keep it stable running at 400FSB?
Your memory is rated to do 400MHz (800DDR) speed maximum, but can also be used at the slower PC2-5400 speed (667DDR) or PC2-4200 speed (533DDR).
The SPD should have entries for all these 3 speeds, with the latency timings growing 'tighter' as speed decreases.
Y'see, the speed in MHz and the latency timing delay in clockcycles are inversely proportional - as the one increases the other decreases, and vice versa.
My SPD timings are:
266MHz - 3,4,4,10
333MHz - 4,5,5,13
400MHz - 5,5,5,15
Now, the theory is that if you were running your memory synchronous with your FSB 1:1 and were not overclocking, 3,4,4,10 timings would come up for the 266 FSB speed automatically.
Since you have your Conroe running @ 400MHz FSB 5,5,5,15 are correct timings for your memory at this speed (and should be delivered if memory set to 'Auto').
I would leave memory on Auto setting but, more importantly you must be aware the memory voltage must be set high enough - 1.8V is not enough.
Manually specify at least 2.0V if your mobo does not supply that on 'default' (which my ABit does).
Interestingly, I run a mild OC with my FSB @ 300MHz (1200QDR) which gives me 2.4GHz CPU.
My memory (set on Auto) comes up 4,4,4,10 at this speed which is between the registered values in the SPD - so it's perfect (and automatically perfect, even better LoL).
At the 400MHz maximum rated memory speed, you could attempt to run the memory timings listed in SPD for the next slower speed ie. DDR2-667 which would be 4,5,5,13 for my memory.
This is unlikely to work without at least 2.1~2.2V supplied to the memory, and very good system ventilation.
So you're good with the 'inversely proportional' thing now? It is a recurring concept that keeps popping up in science,
Thanks for the quick lesson! Things a rolling around the ol' brain pan a little better now.
Curious about the mem voltage though. It's currently running at stock which is 1.8. Everything is running fine, so I haven't bothered raising it. Are you saying it's a good idea to do so even though I'm not having any problems?
I haven't bothered raising it. Are you saying it's a good idea to do so
Well... yes and no.
If you ever need to increase the speed beyond 400MHz or wish to manually specify tighter memory timings, you will need ~2.0V or so.
A lot of memory won't run right (won't even POST in dual-channel mode) with the default 1.8V, so you are fortunate.
A lot of motherboards won't deliver increased voltage and choice of memory for those is very important. Folks are unaware that their new memory needs 2.2V or whatever and their budget motherboard won't supply it... many are pissed off.
Anyway run your 1.8V if it works for you, why not.
Yours and my memory both have the same conservative JEDEC standard timings 5,5,5,15 in SPD - these are designed to POST no matter what.
But I'm just saying, you will do much better overall with 2.0V as it will help your stability and timings. My mobo gives 2.0V on Automatic so, that pretty well sums it up for me.
But yours and my memory have the same spec, however yours does it @ 1.8V - that makes it better than mine if you look at it that way! Mine is rated for 2.2V but it requires 1.9-2.1V minimum...
So basically OCZ is saying "hey, this memory will fly - all you gotta do is give it a little voltage." By specifying a higher voltage they can advertise it as CAS4 memory @ 800MHz - but that's not what's in the SPD though, is it? heheh...
OCZ thinks 2.0V should be the standard default, and ABit agrees. This is why my rig first started up perfectly, no probs (and that was back in the summer too) but I hear about many problems with this stuff - and the cure is always 2.0V :wink:
Thanks again! My memory is listed at 1.8-2.0, so I'd feel comfortable raising it. Plan on pushing it to 430 FSB to break 3.0 as long as my temps hold. I'll goose the memory up a notch or two if needed.
OCZ thinks 2.0V should be the standard default, and ABit agrees. This is why my rig first started up perfectly, no probs (and that was back in the summer too) but I hear about many problems with this stuff - and the cure is always 2.0V ...
That's because OCZ goes for performance over compatibility. There's no problem in making modules that work at the standard 1.8V, but you'll get smaller yields when you do that. The actual cure for modules that don't work at 1.8V (as they are supposed to) is to return them for a free replacement with modules that do work at 1.8V. Understandably, people are impatient and don't want to wait for an RMA, so they let the manufacturer slide.