4GB of RAM, but only 2GB usable?

Dougx1317

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I just replaced my Gigabyte GA-P55-UD4P motherboard with a GA-P55A-UD3. My 4GB of G. Skill DDR3 RAM is only being half used. Windows 7 64-bit says "4GB (2GB usable)", and the resource monitor shows 2GB are reserved for hardware. My bios say one stick is not enabled. I can't find any options to enable it. My gameplay has shown that there probably is only 2GB being used. Does anyone know why this is?
 

Dougx1317

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I've done some testing and here are the results:

Slot 1....Slot 2....Slot 3....Slot 4....Result
2GB.......------......2GB.......------.....Works, but 4GB recognized and 2GB usable.
2GB.......------......-----.......------.....Works with only 2GB. (tried with both sticks)
-----.......------......2GB.......------.....Does NOT work, and post beeps indicate "power error" (tried both sticks)
-----.......2GB.......-----.......2GB.......Does NOT work, and post beeps indicate "power error"

Does anyone have any hints to what's happening? Is this a problem with the motherboard, RAM, or Power Supply?
 

oli_826

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just build a cpu, need your advice. im using i7-920 DO, gigabyt x58-ud5, ocz reaper 6gb 1800mhz, windows 7 ultimate 64bit. my windows properties shows 6.00gb (2.00gb usable) & on my task manager it showed 4.00gb reserve hardware, only 2gb of ram functioning. i tried latest bios, tried also unchecked the maximum memory on system configuration, checked also the cpu pins, loosen the bracket on my cpu cooler also.

i tried yesterday putting 1 stick at a time on each 3 white sockets, 1 stick booted windows on all 3 sockets & the 2 sticks didnt boot windows on each 3 sockets. when installed 3 sticks it can see 6gb but only 2gb usable. ocz 6gb set ram have arrangement on putting in the slots? is it a bad ram or i must reinstall windows?

thanks in advance
 

Ciotto

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i have the same problem, have you resolve the problem clearing manually the CMOS?

@oli_826: i just conctact gigabyte and they can't help me... i have GA-P55M-UD2 motherboard and 4 gb ram but only 2 are usable... (64 bit os)
have you chech in msconfig?
 

oli_826

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saint19 - how can i check gpu memory was added? thanks

ciotto - yes in system config. 5x already check & unchecked maximum memory. did you solve your problem? cleared the cmos already.
 

Ciotto

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i have sapphire 5770 and it can't use shared memory... (or yes?)

@oli: have u clear CMOS? problem is resolved? i not clear CMOS, but if u say that u resolve it, i will clear cmos immidiatly
 

moporoco

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I had the same issue with:
GIGABYTE GA-X58A-UD3R LGA 1366 Intel X58
Intel Core i7-920
G.SKILL 6GB (3 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600

What I noticed was that right after powering the system on, I hid the splash screen and noticed that the RAM was only counting up to 4GB. In Windows it said 6GB of RAM (4GB usable). CPU-Z reported 6GB of RAM.

After hours of troubleshooting I followed a tip to check the pins on the socket of the motherboard. I removed the CPU, placed the mobo under a bright light, and noticed one pin was slightly bent to the side. I straightened it with a tiny flat-head jewelers screwdriver and replaced the CPU. After the next reboot, the BIOS counted up all 6GB of RAM and Windows reported 6GB.
 

rematador

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Hey!
I had the same problem that you had, or have.... and I tried everything that I could have found in the web.... nothing solved the problem until I did what you describe here. Lets say that u you have DDR3(1) and DDR3(2).... install DDR3(1) in slot 1, if it works shut it down and try DDR3(2) in the same slot. One of them will not work. So I think its the Memory cuz I had the same issue. After I found out that, I went and exchanged them for new ones and guess what. I got 4gb again and a 7.5 on windows expiriense index. I hope this had helped you out.
 

If you purchased the RAM individually then RMA {return} the RAM for a Matched Set. Further, if the RAM is NOT compatible then you'll get all sorts of oddball problems. Next, if the DIMM slots are damaged then time for a new MOBO.

Q - What Exact RAM do you have? {provide a link}

Also, see the Resource Monitor image below - the key numbers are the Hardware Reserved, Total & Installed. If the Hardware Reserved is above ~20MB {not GB} then you probably have a BIOS or Compatibility issue. You MOBO does not have an onboard GPU that might suck-up 0.25~0.75GB of physical RAM in the form of Hardware Reserved.

For the 'others' here, assuming no compatibly, onboard GPU, Partitions, bad DIMM slots, bent CPU pins, etc - 9/10 it's a DRAM Voltage issue and/or combined with a QPI/DRAM {IMC} Voltage issue(s). Set the DRAM at or slightly above spec IF the DRAM Frequency is set to RATED SPEED. By Default the RAM should run at 1.5v @ 1066 MHz {most systems} per JEDEC specs {SPD}.

Keep in mind it is VERY COMMON with P55 to have bent CPU pins, especially if there's missing RAM and exponentially so with Gigabyte MOBOs. This is a possibility with the OP. The OP might want to clean the DIMM Slots: Isopropyl alcohol - dampen the RAM pins, insert in DIMM slots, clean and repeat, and allow to dry ~5 minutes.

P55 Slots:
P55_Dual_Channel.jpg


Windows 7 Resource Monitor:
RM_7PRO6GB.gif
 
G

Guest

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i solve this problem

i have notebook Asus X72D and i haved this problem i have 2 X 2GB , its say 4 gb (2gb usable)
all i did is change slots and ,the in start search type msconfig -> boot->Advanced options-> uncheck all number of processors and maximum memory-> ok ->restart comp.. and that is it.....its works,,,,,
 

Fahim Khan

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Jul 23, 2013
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Sorry, very very late reply but there will still be guys with such problems, since i'm using maximus III with xeon x3440, it showed 4gb installed while 2gb usable while running at 1333mhz, my processor bus speed is 1066, so i tried to go manual, turned the ram speed to 1066 and nothing was more awesome than this, all 4gb was usable in bios ... so what's my advice is to lower your rams bus speed because it worked for me, guys using more then 1333mhz with first gen i7 with same p55 chipsets like maximus III, gigabyte p55 ud4 type motherboards, all should try this, hope this helps

JUST TRY TO MATCH YOUR RAM SPEED WITH THE CPU BUS SPEED ...
 

Fahim Khan

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Jul 23, 2013
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Sorry, very very late reply but there will still be guys with such problems, since i'm using maximus III with xeon x3440, it showed 4gb installed while 2gb usable while running at 1333mhz, my processor bus speed is 1066, so i tried to go manual, turned the ram speed to 1066 and nothing was more awesome than this, all 4gb was usable in bios ... so what's my advice is to lower your rams bus speed because it worked for me, guys using more then 1333mhz with first gen i7 with same p55 chipsets like maximus III, gigabyte p55 ud4 type motherboards, all should try this, hope this helps

JUST TRY TO MATCH YOUR RAM SPEED WITH THE CPU BUS SPEED ...
 

RSHARMA9540

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Nov 27, 2013
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if you are used 4gb ram and in bios showing 4gb but yous windows show 4gb ram (usable 2.9 gb) so in that case you have not using graphic card your system resarved 1gb ram for your graphics memory.
solution
1. using graphic card or
2. in bios you nave set internal graphic memory 32mb.

THANKYOU....
IT'S WORKING 100%
 

Swany489

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Feb 21, 2014
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My computer also said "4GB (2GB usable)", and the resource monitor showed 2GB was reserved for hardware. I tested both sticks of memory individually and they both worked. I then moved one stick to an open slot, (they were both in the "blue" slots the motherboard manual suggested), and now both sticks are usable.
 

Boris Milanovic

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I voted on the answer with explanation of taking automatically 1 Gig for Ultimate ( I haven't read all answers just few interesting), and rest ( 1 or 0.9 Gig for ADDITIONAL R.A.M for GPU, even tho you think 1GB is enough for itself I don't play 10D games or whatever... I need that "additional" for performance/ business/ I have the same problem. :) So, I suddenly didn't wanted to THINK that THAT is the case, but- cool. I think you will see more of Boris from Serbia here. ;) all best, Boris Milanovic.