A8V problem with 4 Dimms

[AsymptoticNull]

No matter what I do I can only get my A8V deluxe Rev 2.0 to detect half the installed memory. On post it only shows detects 1024MB when I have 4 Corsair CMX512-3200 installed. I've tried updating the Bios, (to the latest beta 1009.03) but still no go as far as detecting the rest of my ram. The system boots fine otherwise and shows no signs of any stability problems. Any suggestions?

 

[Squally Leonharty]

With 4 DIMMs you need to set the Command Rate to 2T.

I should also mention that I'm not saying that will fix it with 100% certainty. I'm not very familiar with RAM stuff. But yeah, it's true: 4 DIMMs require 2T, so set CMD to that if you haven't done so.

 

[AsymptoticNull]

Well I have tried the 2T setting as enabled, disabled and auto but not one allows the system to detect the missing memory.

 

[Rhin0]

may have trouble getting to to work at all : =(

 

[Wolftrap101]

Also make sure your FSB is set to 333 not 400 as 400mhz with 4 dimms is acutally overclocking it This is a limititation with the AMD 64 chips.

 

[kogase]

It's a limitation in the DDR spec.

 

[AsymptoticNull]

I've tried swapping the modules slots, memtest86 on individual modules and in paired configurations without errors, various bios memory timings settings including setting fsb to 333 but absolutely nothing I do allows all 2048MB to be recognized. What is wierd is that programs like cpu-z and sisoft sandra recognise that there is dimms installed in all four slots, but the motherboard on post only shows 1024MB. Mysterious and quite frustrating.

 

[Dewey]

Originally posted by: Wolftrap101
Also make sure your FSB is set to 333 not 400 as 400mhz with 4 dimms is acutally overclocking it This is a limititation with the AMD 64 chips.

The Asus A8V FAQ makes it sound like 4 DIMMS should work fine at 400MHz, but will default to 333.

http://www.asus.com/support/fa...a.aspx?KB_ID=100090255

 

[jkresh]

there is an option under the memory settings tab for running 4gigs or more, have you tried enabling it, maybe it is required for 2gigs or more? (though it shouldnt be)

 

[Squally Leonharty]

Originally posted by: jkresh
there is an option under the memory settings tab for running 4gigs or more, have you tried enabling it, maybe it is required for 2gigs or more? (though it shouldnt be)

Right, I totally forgot about that. There is indeed an option in the memory configuration section of the BIOS that allows 4GB RAM to be recognized. Enable it and you should be fine.

Edit: I'm at uni right now, so I can't look up what it's called exactly, but it should be obvious (otherwise look at the help panel on the right side of the screen). That should do.

 

[AsymptoticNull]

Toggling the 4GB ram option did not solve the problem.

 

[GTiBri]

I have a very similar problem. I have four cmx512-3200c2 corsair XMS dimms. I can only get two to work. If I have four in it tells me that "the system failed to boot due to cpu overclocking." I'm not at home but right now but when I get a chance I will try manually setting the ram to 333mhz.

Otherwise I'm returning this motherboard. It works great EXCEPT I can't use all of my ram. That sucks.