Memory timings

cuda-uk

cuda-uk

cuda-uk

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I have an Asus crosshair III and have a problem with the memory timings, I have also posted this under the memory section but thought I would try here as well, here is a copy of that post,

Hi this is my first posting on this board and I am hoping that someone can help me. I am a complete numpty when it comes to overclocking and tweaking etc but i have noticed a problem with the ram timing on my Corsair Dominator ram.
I built this system earlier this month and was hoping it would last me for the next few years. I ordered Corsair memory chosing the dominator DDR3 2x 2gb
TW3X4G1600C9D. After the system had been built a couple of days the temperatures were a little on the high side due to the old case i was using I rang overclockers again to order a new case and water cooler and asked about putting another 4 gig of ram told them what I had and was told there would be no problem and to order the same again, I did. The pc seems to run ok but not really any quicker than it did before, so
Last night I ran a program called CPU-Z which as you know gives a report on your system and to my suprise it showed me that my memory in stead of being 1600MHz, at latency settings of 9-9-9-24 was in fact RAM Speed : 668.9 MHz (3:10) @ 9-9-9-25.

Is this a problem ??? How do I fix it (in very simple steps)??? Was i given the wrong imformation and whats my next step???

The people at Overclockers have given me a great sevice and pointed me to this forum for help.
 
The trouble is I have not got a clue as to what to do, is there a step by step idiots guide for doing this, I dont want too end up with a dead pc
 
I don't know what speed your CPU is running at I presume your Front Side Bus is running at 200MHz? your RAM divider is 3:10 (3.33) so 3.33 x 200 = 666MHz. So your effective RAM frequency is 1332MHz (666 x 2) Dual Data RAM or DDR uses the rise and fall cycles of a clock so the effectively doubles the bandwidth.
The important timings of RAM are explained below:

CL: CAS Latency. The time it takes between a command having been sent to the memory and when it begins to reply to it. It is the time it takes between the processor asking for some data from the memory and it returning it.
tRCD: RAS to CAS Delay. The time it takes between the activation of the line (RAS) and the column (CAS) where the data are stored in the matrix.
tRP: RAS Precharge. The time it takes between disabling the access to a line of data and the begin of the access the another line of data.
tRAS: Active to Precharge Delay. How long the memory has to wait until the next access to the memory can be initiated.
CMD: Command Rate. The time it takes between the memory chip having been activated and when the first command may be sent to the memory. Sometimes this value is not informed. It usually is T1 (1 clock cycle) or T2 (2 clock cycles).

These have to be set manually in the BIOS according to your RAM spec these will be stickered on your modules or google the part number! Yours are 9-9-9-24 I think, dunno what your Voltage is for the RAM though, 1.5V I think!

Your RAM is running lower than rated because your RAM multiplier is incorrect. You need a ratio of 1:4 (4) to give you your desired speed.
Example, 200 x 4 = 800MHz x 2 = 1600MHz DDR.
Hope this helps
Good luck!
 
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Great thanks for the reply it looks simple enough..(did I just say that):)

Whats the worst that could happen if i get it wrong ??? I know this board has a reset feature on the back if it goes all wonky bent is it just a case of resetting the board or should I make a note of all the settings before I dive in.

Like I said i am a complete numpty with this sort of thing..:o
 
I think i may have sorted it with all your help Jonnygrunge, have a look at this please ,is this what it is meant to be?

it looks ok to me:confused:



Fire wizzard thanks for cleaning that up and I have sorted out my Sig too..;)
 
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