Only 2GB detected out of 4GB

[brownpixel]

Hi,
I have 2 * 2gb corsair 800mhz ddr2 ram and ASUS P5Q Pro Motherboard
I have a problem that the BIOS as well as Vista Ultimate (64b) are detecting only 2gb ram.
I tried removing 1 ram card, but then the computer doesnt start at all (gives 1 long beep - 2 short continuously)
I tried rearranging the cards, still no effect.
Computer is running stable right now with only 2gb ram available to use.
Please suggest.

 

[jerreece]

First thing I think of is whether the system will boot with BOTH DIMMs separately. In other words, put in memory stick # 1, then boot. Then take # 1 out, put in # 2, and see if it still boots. This is to resolve whether one stick may actually be defective.

The other thing I'd try would be to update your BIOS to the latest version and see if that works. Corsair is good memory, so I'm doubting the motherboard just doesn't play with it. But you may also wish to check with Asus to make sure your particular memory sticks are indeed compatible with the motherboard.

If none of that works, you may want to download a memory test program and run a test on those memory sticks. Could have one that's bad, but is boot-able.

 

[KyleSTL]

I've had this problem before, many years ago. Turned out to be of the the sticks not fully seated in the DIMM slot. That's the first thing I'd check.

 

[dallasjoh]

Check in your BIOS that Memory Remap is set to Enabled. You can also find this information in your manual on page 3-26 section 3.5.3 under Northbridge Chipset Configuration.

 

[stoner133]

What ever you do don't update the BIOS unless the newer BIOS file fixes the problem your having. Read the release notes on the new BIOS file. If it addresses memory problems then its worth giving it a try. Never just update the BIOS for the sake of updating. Even more so since your having problems with the system.

Testing the memory is your first step.

 

[brownpixel]

First thing I think of is whether the system will boot with BOTH DIMMs separately. In other words, put in memory stick # 1, then boot. Then take # 1 out, put in # 2, and see if it still boots. This is to resolve whether one stick may actually be defective.

The other thing I'd try would be to update your BIOS to the latest version and see if that works. Corsair is good memory, so I'm doubting the motherboard just doesn't play with it. But you may also wish to check with Asus to make sure your particular memory sticks are indeed compatible with the motherboard.

If none of that works, you may want to download a memory test program and run a test on those memory sticks. Could have one that's bad, but is boot-able.

I've done that, computer doesnt boot with only 1 memory placed.
I've heard some bad things about BIOS update failing in ASUS P5Q in other threads, so I'll probably not do that.

I've had this problem before, many years ago. Turned out to be of the the sticks not fully seated in the DIMM slot. That's the first thing I'd check.

Will check it out again, thanks for your help.

Check in your BIOS that Memory Remap is set to Enabled. You can also find this information in your manual on page 3-26 section 3.5.3 under Northbridge Chipset Configuration.

I've already done that, enabled it, was still 2gb ram, disabled and still 2gb.

What ever you do don't update the BIOS unless the newer BIOS file fixes the problem your having. Read the release notes on the new BIOS file. If it addresses memory problems then its worth giving it a try. Never just update the BIOS for the sake of updating. Even more so since your having problems with the system.

Testing the memory is your first step.

I ran a memtest from the bootable disk, it also detected only 2gb ram

 

[Zorg]

Possible bad slot, try slots 2 and 4.

 

[dallasjoh]

Are you putting the memory in the same dimm everytime. Have you tried putting the one stick in Dimm A2 or B1. Could it be that Dimm A1 is bad?

Ah Zorg you beat me.

 

[brownpixel]

@KyleSTL
@Zorg
@dallasjoh
Thanks a lot!
I've placed the memory in B1/B2 now, and everything works fine!
This forum is great!

 

[dallasjoh]

Contact ASUS tech support and explain your problem and your troubleshooting and get an RMA. It appears you have at least one bad dimm (A1).

 

[aevm]

OK, but if A1 or A2 is bad you should still RMA the motherboard. For one thing you want the ability to upgrade to 8GB and you paid for it, so why lose it. For another, there may be other defects too.

LOL, dallasjoh you beat me. You can type fast if you try