memory help
hi iam new to all this so if i make a mistake ill applogise now
i have a crosshair II formula and im trying to work out what the advance memory setting should be to enable me to run my memory as it should be that is ocz 1066 pc2 8500 ddr2 i know the cas is 5 the trcd is 5 the trp is 5 and the tras is 18 but cpuz only says it is pc2 6400 there are more advance setting for the momory and wondered if any one would know the more advance settings for it as i cant find them any where i have consulted the manual but sadly i dont fully understabd it all hope some one can help thanks very much
i have a crosshair II formula and im trying to work out what the advance memory setting should be to enable me to run my memory as it should be that is ocz 1066 pc2 8500 ddr2 i know the cas is 5 the trcd is 5 the trp is 5 and the tras is 18 but cpuz only says it is pc2 6400 there are more advance setting for the momory and wondered if any one would know the more advance settings for it as i cant find them any where i have consulted the manual but sadly i dont fully understabd it all hope some one can help thanks very much
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Comments
Every AM2+ platform I have used seems to recognize the PC8500 as PC6400 by default, I suppose that is because PC8500 is not a JEDEC standard speed. Normally you just need to tweak the bios to get it set properly to the PC8500 bandwidth. Sometimes the Phenom's on board memory controller can be a limiting factor in how many dimms it will handle, two in dual channel seems to work in most cases, but when some go out to four sticks, its a mixed bag, sometimes you can manual set it run a few benchmarks and its fine, other times you just can't get it to run stable at PC8500.
I have very limited experience with your 780a chipset, I only have built with it once for a friend, and for that build I only used PC6400. If you have trouble getting it stable, don't loose sleep over it, the gain in performance is nominal, but I understand how you feel wanting to get your money's worth.
How familiar are you with your system bios?
Thanks very much for your help i realy do apperciate it.
Just now im running the memory ungangged though iam running windows 7 64bit oc i dont know if that has any refrance.
there are 4x2gb sticks of ocz ddr2 platinim pc2 8500 amd thats part of the problem i dont fully understand why it shows as 6400
how ever iam very familiar with my bios and no matter what i do i dont seam to be able to get it to recognise correctly
thanks very much all the best shaun
I'll find the article, but there was something explaining the Phenom memory controller limitation to not accept four dimms of PC8500. Now, I have been able to run it on some boards, I had a Gigabyte 790 board that when I gave some OCZ reaper a little extra voltage (2.1 if I remember correctly) it ran all four sticks stable at 1066, but that tends to be the exception and not the rule. Have you checked your voltage? Its not uncommon for quality DDR2 to be specked to 1.8 volts or so for PC6400 operation, and up to 2.0 or even as much as 2.2 in some cases for PC8500. Perhaps you need to adjust the voltage? Be careful obviously, check where you are at if you have not done so. I'm fairly confident that 2.0 will not cause a problem on any DDR2 OCZ branded stick, perhaps 2.1 or 2.2 is necessary to run DDR2 1066 stable, beyond that it might get a little too hot to handle, but even then, the Phenom memory controller may still be the limiting factor. I would try to feed the RAM a little extra voltage if you have not already (keeping in mind the factory label specs).
Keep in mind that if you can't run it at 1066, don't let it drive you mad. Its one of those funny little fine print limitations that they don't always do a good job at explaining, but PC8500 is in a sense factory overclocked PC6400 and most AM2+ boards have a little disclaimer about it not being able to run all four sticks at that rated speed. I personally run 8 GB of PC6400 timed 4-4-4-12 and let me tell ya, that is massive memory bandwidth, RAM should never be your system bottleneck even if you can't get it past PC6400. So if you want, see what a voltage bump will do for you, but if I am being honest, if I could run that high quality ram slightly cooler with a small trade off in bandwidth, I might, considering you have a whopping 8 gigs on the board.
2. Phenom II memory downclocking explained & overcome
Thank you sir, I was just looking for that.
well im now at 2.2 volt on the memory and it has not made a diffrance
thankyou very much for you help ill keep playing and if i find out how or any more info ill let u know