[Solved] Dual Channel memory problem

I am having Intel DG31PR with Intel Core2Duo E7300 processor.

I have 2x2GB DDR2 800MHz Transcend memory.

both are 800 MHz but when they operate together the bios and CPU-Z showing only 667MHz.,..

i bought the same two model from Transcend JM800QLU-2G but still there is timing difference between the two...am i getting 800MHz or 667 really...can it cause trouble to my motherboard or memory...should i try getting the same memory ie the older model with same name,,,,

when both memories are operating individually they show 800 MHz....actually i bought same models from Transcend one is older and one is new with following timings:

older : 5-5-518
newer: 6-6-6-18

although they carry same model no. why thr is timings diffrence...

as per my knowledge older one is fast!! but why would they decrease performance timings in newer model?

u tell which model is better i will get same stick then....

i m posting images of slots and memory from CPU-Z

hope that cl;ears evrything u wanna know....

yes they arent matched even they are from same maker with same model....

ii can change one module u suggest what would be better option out of these two??

(5-5-5-18) + (6-6-6-18) @ 667 MHz

or 2* (6-6-6-18) @ 800 MHz

i m having first combination now i can get the second combi by returning the older one...i cannot get the older model ...I am from India.

what matter more in performance? timings or frequency?

should i get another "new" one or keep the existing new+old at 667?

can you just manually set the memory to 800mhz in the bios when they are installed as a pair? vs having the motherboard autodetect and auto set them?

it might be that easy.

ok so i will be going for 800MHz @ CL6 cos thats the only option avail...thanks for the help guys...

You could also manually set the timings to 5-5-5 18 but leave it at 400 and see if the "new" ram will pass memtest. Alot of times companies will state specs just to be on the safe side.

I am now running two modules of CL=6 @ 800 MHz. Just let me know out of these two which is faster and recommended?

1. One CL5 800MHz module + 1 CL6 800MHz module = 667MHz


By dcosmopolitan at 2009-09-20


2. Two CL6 800MHz module = 800 MHz


By dcosmopolitan at 2009-09-20

I'll try again!

1. One CL5 800MHz module + 1 CL6 800MHz module = 667MHz CL=5 -- This is your BIOS's response to finding un-matched RAM modules attemping to run them as dual channel. Since it cannot match them at 800MHz, it drops down to 667 speed which it finds a match in CL specs. This is likely NOT a stable configuration - you should NEVER use un-matched memory modules in a pair of dual channel slots.

2. Two CL6 800MHz module = 800 MHz CL=6 -- The system finds a pair of perfectly matched modules and rewards you by showing them in 800MHz mode. Since they are matched, you can easily change them to 667MHz mode if you want - so you'd have the exact same specs (667/5) that you have above.

Again, since you cannot get two modules with 800/5 specs, the best choice is two with 800/6 specs. ANY 800/6 RAM will run at 667/5 - so which is faster is not an issue. As for whether 800/6 is faster than 667/5, it's a complicated calculation and people will disagree about the results. But again, no one will tell you to use un-matched modules as dual channel memory.

1. One CL5 800MHz module + 1 CL6 800MHz module = 667MHz << BAD - DO NOT USE because memory modules do not match.

2. Two CL6 800MHz module = 800 MHz << GOOD - Memory is matched and should be stable.

3. Two CL6 800MHz module @ CL=5 << BEST - but not an option to you unless you return ALL your modules and replace them with faster model or faster Brand of RAM.

Your BIOS apparently has, among others, the following choices regarding RAM:

SDRAM Frequency
in Advanced > Chipset Configuration or Advanced > Memory Configuration
• Auto
• 266 MHz
• 333 MHz
• 400 MHz
Allows override of detected memory frequency value
If you wanted to, you can manually reset choice 2 above to 667MHz and see you have CL=5 automatically.

SDRAM Timing Control
in Advanced > Chipset Configuration or Advanced > Memory Configuration
• Auto
• Manual – Aggressive
• Manual – User
Defined
Auto allows timings to be programmed according to the
memory detected.
Manual – Aggressive selects the most aggressive user
defined timings.
Manual – User Defined allows manual override of
detected SDRAM settings.

You can experiment with the CL and other settings with the above BIOS option and others. Your pair of matched RAM (choice 2) may run fine at 800MHz and CL=5 - you have to try it and see.

DO NOT KEEP UNMATCHED RAM (CHOICE 1)

Great!

The quotes I had above came from the Webpages on your motherboard.
http://www.intel.com/Products/Desk [...] erview.htm
Your motherboard manual:
http://download.intel.com/support/ [...] 201_en.pdf
This is where I found them - in the Glossary of BIOS terms. This may be general terms and not specific to your board.
http://www.intel.com/support/mothe [...] 020304.htm
You should download everything there and save all the webpages so that you can easily refer to them. Do not update your BIOS unless you think it will do something good for your system - but you can save the updates, if any, for later use if needed.

Be careful here. If the module is CL6 @ 800 then it is also CL5 @ 677. ------ But you have to experiment to see if the good pair will perhaps run well at CL5 @800. [/quotemsg]

Yes, normally it is fine. Any very different settings may have to be tested. But if your system seems to work OK with changing CL to 5 at 800MHz, it's probably OK. If you make a setting that is not allowed, usually the motherboard will 1)not boot at all 2)not complete POST or 3) not enter Windows. If that's the case and you cannot get into the BIOS to change the settings, then you use the motherboard jumper to CLEAR CMOS and reset it.

The software which I use to set these values is designed specifically for my board - and I don't like it very much. I'm not sure if there is any general software. I set the values in BIOS, then boot and test the changes. I use the programs CPU-Z and CPUID Hardware Monitor available at www.cpuid.com and also Prime95 available at www.mersenne.org to test the memory settings. A test only for memory errors is memtest86 which is run from a CD or a diskette - this you use when you think memory might be bad.