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Questions about GIGABYTE products => Motherboards with Intel processors => Topic started by: geossl on March 27, 2012, 01:19:54 pm

Title: 8G Ram installed but 4G usable
Post by: geossl on March 27, 2012, 01:19:54 pm
Dear All,
 
  My motherboard is P55A-UD3. There are 4x2G RAM.

  However, the bios reports all 4 modules of RAM but 2 dimm channels are disabled. Win7 (64bit) reports 8G RAM (4G Usable).

  How to fix this.

  I already loaded the latest BIOS.

Title: Re: 8G Ram installed but 4G usable
Post by: Dark Mantis on March 27, 2012, 03:47:22 pm
Hi and welcome.

I would think that it is quite possible that this is down to a bent pin or pins on the CPU socket. Have you had any BSODs recently ? Also what voltages etc are you using at the moment ?
Title: Re: 8G Ram installed but 4G usable
Post by: Lsdmeasap on March 28, 2012, 06:41:29 am
What voltages do you have set?   Can you please test with three sticks and see if you get 6GB?  Two sticks will always need to be in the white slots, but if you do get 6GB with 3 sticks, then test the other slot with that third stick to, this way you know all the slots are OK and no bent CPU socket pins.

Then if that is all OK, it's probably just voltages need adjusted, maybe ram voltage increased a little more than spec, or QPI/Vtt may need adjusted to 1.2-1.4+ depending on your CPU
Title: Re: 8G Ram installed but 4G usable
Post by: geossl on March 31, 2012, 10:47:02 am

Manual said it cannot use 3 modules , so I just test with 2 modules in all combination of 4G.
It seems that all four ram modules is working.

Besides, I am using default voltage. I did not overclock. Is this related to voltage?


Hi and welcome.

I would think that it is quite possible that this is down to a bent pin or pins on the CPU socket. Have you had any BSODs recently ? Also what voltages etc are you using at the moment ?
Title: Re: 8G Ram installed but 4G usable
Post by: Dark Mantis on March 31, 2012, 10:52:58 am
Well it is quite possible that you will need to increase the voltage a little to compensate for filling all the slots and putting an exttra loading onto the memory controller. If your default voltage for these sticks is 1.5v then try increasing it to 1.55v. If the default is 1.65v then up it to 1.68v -1.70v. Just m,ake sure that you maintain the 0.5v max differential between the QPI/Vtt and the DRAM voltage.
Title: Re: 8G Ram installed but 4G usable
Post by: Lsdmeasap on March 31, 2012, 09:59:57 pm
I was trying to get you to test the slots really, not the memory itself.   You can use 6GB / 3 modules if you want, please test as I mentioned previously, thanks!

As for voltage you may need to increase the QPI/Vtt voltage, the ram voltage should be fine at it's stock spec'd value.   You need to do the test I mentioned above before anything else though, so you can see if you have bent CPU socket pins.   Or you can remove the CPU and look if you want, if you do that please take several images for us to look at.  Do this in a well lit room with no flash, and the camera set to macro mode if it has that option.  Take the images from several angles off to the side looking into the CPU socket, just not directly over it. 

And be VERY Careful while there is no CPU in the socket!!!
Title: Re: 8G Ram installed but 4G usable
Post by: Dark Mantis on April 01, 2012, 06:02:13 pm
And be VERY Careful while there is no CPU in the socket!!!

You wouldn't be the first person to put the camera lens down onto the socket and bend some pins whilst at it!  :o
Title: Re: 8G Ram installed but 4G usable
Post by: Lsdmeasap on April 02, 2012, 07:02:54 am
Any updates on this?  Just checking in!
Title: Re: 8G Ram installed but 4G usable
Post by: geossl on April 04, 2012, 01:22:41 pm
I cannot get it with 6G.

With the white slots is filled, I try all combination but cannot achieve 6G.

Only Channel 1 and 2 can be enabled.

I also took out the CPU but cannot find any pin bent as the pin is so close and small, it is packed so dense together.


Any updates on this?  Just checking in!
Title: Re: 8G Ram installed but 4G usable
Post by: Dark Mantis on April 04, 2012, 05:36:41 pm

I also took out the CPU but cannot find any pin bent as the pin is so close and small, it is packed so dense together.


That was precisely why Lsmeasap and I asked you to take photographs of the socket. We are used to seeing these pin configurations and spotting anything out of the normal.
Title: Re: 8G Ram installed but 4G usable
Post by: JFC15 on April 04, 2012, 09:13:33 pm
I had this same problem... this is what worked for me...

Check the system configuration settings
 This problem may occur because the Maximum memory option is selected incorrectly. To fix this, follow these steps:

1. Click Start, type msconfig in the Search programs and files box, and then click msconfig in the Programs list.
2. In the System Configuration window, click Advanced options on the Boot tab.
3. Click to clear the Maximum memory check box, and then click OK.
4. Restart the computer.
 
Title: Re: 8G Ram installed but 4G usable
Post by: Dark Mantis on April 05, 2012, 10:09:29 am
I had this same problem... this is what worked for me...

Check the system configuration settings
 This problem may occur because the Maximum memory option is selected incorrectly. To fix this, follow these steps:

1. Click Start, type msconfig in the Search programs and files box, and then click msconfig in the Programs list.
2. In the System Configuration window, click Advanced options on the Boot tab.
3. Click to clear the Maximum memory check box, and then click OK.
4. Restart the computer.
 

That is another point that is quite possibly the issue. As JFC15 has just said it is worth checking out. Here is the shortened version for you:

Start/run/msconfig/boot/advanced options/maximum memory
Title: Re: 8G Ram installed but 4G usable
Post by: geossl on April 06, 2012, 10:59:28 am
CPU PHoto....
Title: Re: 8G Ram installed but 4G usable
Post by: geossl on April 06, 2012, 11:00:10 am
Socket Photo
Title: Re: 8G Ram installed but 4G usable
Post by: geossl on April 06, 2012, 11:01:16 am
I have also tried to configure with Start/run/msconfig/boot/advanced options/maximum memory , unchecking the maximum memory.

However, is does not work.
Title: Re: 8G Ram installed but 4G usable
Post by: Dave noob on April 06, 2012, 02:25:51 pm
I had the same problem two days ago when cleansing my computer. I pulled out everything from the board including batery (to clear CMOS), and when I installed everything back again and started the computer, bios shows that memory is 4 GB but just 2 GB enabled.

I got it fixed by pulling out memory and installing it back while shorting the "clear CMOS jumper". I have P55A-UD3P with F14 bios, so I guess it may help.
Don't forget to umplug the power cord before doing this.
Title: Re: 8G Ram installed but 4G usable
Post by: Dark Mantis on April 06, 2012, 08:52:28 pm
If you want to clear the CMOS at least do it properly and leave it for a few hours to make sure that all charge has dissipated. Like this:

Remove the power cable from the mains supply and then press the power switch on the case for a few seconds just to drain any residual energy in the PSU capacitors.

Once done remove the motherboard battery for at least one hour before replacing it.
 
Next plug back into the mains supply and boot.
 
You will now need to enter the BIOS by pressing DEL and load Optimised BIOS Defaults.

Make any other changes to the BIOS settings to suit your self like disabling the floppy drive, disabling the full screen logo and making the HDD the primary boot device and then press F10 to save and exit.


Regarding the photos I am afraid they were of rather poor quality and the flash especially ruined them. Better to use "macro" setting and with good natural light or at least diffused lighting so there is no glare. Please post some more.
Title: Re: 8G Ram installed but 4G usable
Post by: JFC15 on April 07, 2012, 02:07:09 am
hmmmm...   

Tell me about your memory modules...  make/model

All modules are the same make/model... correct?

What is your DRAM voltage setting in BIOS?  Since you are using all the slots, you might have to increase board default voltage.

Did you try testing memory with MemTest86?

Title: Re: 8G Ram installed but 4G usable
Post by: Dave noob on April 07, 2012, 03:40:38 pm
Something strange happened when just 2 GB of 4 GB was usable. WEI scored my memory 5.5, down from 7.9 but my 3DMark vantage score goes up to 18576 from initial 18100. Resource meter reported that the 2 GB is reserved to be used by bios and hardware.

I just wonder, if I install 8 GB bust just 4 GB enabled, may I have even higher score in 3DMark?
Title: Re: 8G Ram installed but 4G usable
Post by: Dark Mantis on April 07, 2012, 08:56:24 pm
I can only suppose that if the extra 4GB had been allocated to the graphics processing rather than the system it would have given you a higher graphics rating in WEI at the expense of the memory score. I just can't imagine why iot would happen like that.