GA-P55M-UD2 Ram trouble. Can't enable 8gb

[Xses]

I've got 2x CMX4GX3M2A1600C9 4gb kits. But i can't get them to work...
The BIOS sees all the RAM but will just use 4gb any way i put them. Theese DIMM¨'s are also dual channel, but won't work as dual channel.
If i put one in DIMM3_1 and one in DIMM3_3 as the maniual says...it just enables 2GB of RAM.

Is it a defektive MB or a configuration problem?

[Dark Mantis]

Hi and welcome to the Gigabyte Forum.

Firstly a few more details regarding your setup would be extremely useful. Are you running Windows 7 32bit as that would explain why you can only use 4GB of memory ?

[Xses]

Hello.
Im running Win 7 64bit.

[Dark Mantis]

Hello.
Im running Win 7 64bit.

Thanks for all the extra information I asked for!

[Xses]

Hello, sorry for giving you so little info. I switched from 4x2gb kit to 2x4gb kit, thats why  i did not provide any more info.

But still can't get it to work in dual-channel mode. What kind of info is it that you need?

MB : GA-P55M-UD2  F11 Bios.
Windows 764bit.
8gb RAM (2x4gb CMZ8GX3M2A1600C9) 9-9-9-24 @800Mhz 1,5Volt
ATI Radeon HD 5770
CPU : I5 750 @2,57Ghz


...addon info : I haven't read up on what Dual Channel actually do..  But i finnaly got CPU-Z to go for Dual channel, but i have only 4gb avaliable.
Is that how it works.. double the bandwith but halfen usable RAM?

[Dark Mantis]

Hi again,

Thanks for the extra setup info much more help. Don't forget we only have what you tell us to go on.

No the double bandwidth doesn't cut down on the amount of usable memory. What slots have you inserted the sticks into ?

[Xses]

As of now they are in DDR3_2 and DDR3_1  and show 8gb Singel mode
This is how the MB is marked and slots.
DDR3_1 = 1
DDR3_2 = 2
DDR3_3 = 3
DDR3_4 = 4'
I've tried this :

• 1+2 8gb Usable Singel
• 1+3 4gb Usable .In BIOS it sees 8 but ony 4 enabled
• 1+4 4gb Usable .Iin BIOS it sees 8 but only 4 enabled
• 2+3 No Boot
• 2+4 No Boot
• 3+4 No Boot

No boot means no picture on screen. Tried to reset BIOS between each time but same results.

Thanks for helping me.

[Dark Mantis]

To be in Dual Channel mode the sticks need to be in DDR3_1 and DDR3_3 or DDR3_2 and DDR3_4. The first pair is preferable though.

[Dark Mantis]

I would suggest that if you put them in these slots and they refuse to work properly that you manually enter the timings and voltage in the BIOS rather than leave it on Auto. Post back with your results.

[Xses]

i've now tried to not use auto but manual settings.
It says 8gb but only 4 usable... but clames do work in dual mode.. (and the computer works noticable slower)
See attachment  for pic's

[Xses]

And for slot 1 and 3.

[Dark Mantis]

Have you set them up so that you are using the same settings as the XMP would for 1600mhz ?

[Xses]

Yeah, did try that to now. Same problem. Tried to tweek with som manual Mhz and other settings but then i only rebooted or did'nt wanna start.
No luck yet. Defective MB?

[Dark Mantis]

No defective user !  Much more likely that it is something we haven't done yet.

There are many things that it could be caused by. Try this next as it is easy. Check that you have the right setting for using the full memory.

Start/run/msconfig/boot/advanced options/maximum memory

[Xses]

  Funny guy. defective user....

Tried the ms config. but no luck there either.
Remeber this in Slot  1+2 i get 8gb usable but then only in  Singel mode.
Taking pictures of every BIOS screen is the next thing?