BIOS detects 4GB RAM, WIndows detects 2GB.

[SeanGilbreth]

When building my computer, I made sure that I was future-proofed in terms of RAM, so I installed 4GB of RAM (4 x 1GB sticks). My problem is that Windows only detects 2558 MB not the full 4096 MB. I find this very odd, as my BIOS reads that I have 4GB, but Windows doesn't. (BTW, this was the case with XP and Vista).

Can anybody suggest a solution?

Thanks for any help!

 

[stduc]

How much does memtest86 detect? (

http://www.memtest86.com)

Build a bootable CD or floppy and test - report back here.

 

[SeanGilbreth]

I have just noticed that my BIOS now says I only have 2GB, I'm pretty sure when I first put the computer together that it said 4GB. Anyway I started a MemTest, here is the description it gives me:

Athlon 64 X2 2612 Mhz
L1 Cache 128k 21410 mb/s
L2 Cache 1024k 5319 mb/s
Memory 2559m 1700 mb/s
Chipset: nVidia nForce (ECC: Disabled)
Settings: RAM: 163 Mhz (DDR326) /cas: 2.5-3-3-7/ Dual Channel (128 bits)

 

[JSD7878]

Ok here's some question I would have for you
1) What is the make model of your MB?
2) Does the MB except 4GB of memory?
3) The memory modules are they seated properly
4) Are the contacts dirty?
5) I assume all the memory modules are the same manufacturer?
Also a future suggestion for me out of laziness mainly I usually will go to crucial.com and use their memory calculator to make sure I'm buying ram that will work in my MB. Another thought too I'm not sure if anyone can ever be future-proof I think it's only possible to be ahead of the curve for a year at the most.

 

[stduc]

OK
I guess you are sure you have 4 1MB sticks of RAM?

Time I think to pull the power from the HDDs & CD-ROM drives (just makes life easier) (assuming your booting from floppy for memtest - adjust accordingly if not)

It's time to test each stick of RAM one at a time in each slot to check the slots and the RAM. Then test adding 2 then three etc. run at least one cycle of memtest each time.

Bad RAM and badly configured RAM cause windows so much grief that I always do a final overnight run of memtest before I even start installing windows on any new machine.

Also read your mobo manual and verify you have the right kind of RAM and are pairing it up correctly if it needs that. Mobo manuals can also be wrong. Also check you BIOS settings (RAM clock/refresh/etc) are correct. Sometime you have to play around quite a bit to get memtest to verify all is well. If memtest fails at any point then windows will screw up big time.

I had one mobo with 3 RAM slots that claimed I could put RAM in any which way I liked - turned out not to be true - took me 2 days to get the BIOS right and the order right so that 2*256 and 1*512 would give me 1Gb of working RAM.

 

[wahnula]

Did you install the PAE /3GB switch in boot.ini? Windows will not see more than 3 GB RAM without Physical Address Extension.

Tony

 

[stduc]

Windows will see the RAM but waste it without the 3GB switch! Good point to remember later when he has 4GB working.

 

[SeanGilbreth]

Thank you everybody for the replies:

JSD7878, here are my responses:

1)LANPARTY UT NF4 SLI-DR Expert

2)MB supports up to 4GB of memory.

3)I removed them all, and reseated them firmly.

4)The contacts are very clean.

5)All of the memory modules are the exact same type, made by Kingston.


studc: Yes, I am using 4 x 1GB sticks. I will try out your suggestions! Thanks!

wahnula: Thank you for the tip, I will try your suggestion when I can get the BIOS to read my 4GB.

Thanks again everybody for your time!

I will report back as soon as possible.

 

[SeanGilbreth]

The test of my first stick of RAM in slot 1 is now executing, however will I have to test each stick of RAM in EACH slot, or can I just test 1 stick in all slots, and then only the remaning sticks in the 1st slot?

 

[wahnula]

Try resetting your BIOS to Optimum System Defaults. I did this on my 4 GB RAM server and solved the problem of the BIOS not seeing all the RAM. If you have custom settings in BIOS go through and log them with pen and paper, don't count on the BIOS export to remember them.

Tony

 

[SeanGilbreth]

Okay, I've figured that I am not going to MemTest my RAM unless I absolutely need to; it spent 3.5 hours test one stick so it's a bit time consuming. However, I have tried many different RAM combinations in the slots:

Ones which worked:

1
2
1 & 2
1 & 3
1 & 2 & 3 & 4 (Obviously I can run Windows as normal, but all of my RAM is not being detected.)

Ones which didn't (I know they don't, as the computer won't boot, and I get a series of long beeps.):

3
4
1 & 4
3 & 4
1 & 2 & 3
1 & 2 & 4
1 & 3 & 4

I've also set my BIOS back to it's original state and it still doesn't detect the extra 2GB.

Does this clear the problem up a bit more?

 

[Glenn9999]

Windows will see the RAM but waste it without the 3GB switch! Good point to remember later when he has 4GB working.

Here's the right answer. The memory is likely all working correctly. Windows XP won't "see" anything beyond 2GB without the /3GB switch defined at boot. And programs can only use the extra GB if they've been compiled to do so.

I don't know how Vista is going to be regarding this matter. But for Windows XP, this is a little bit too future-proofed.

 

[franklin97355]

Also this board will set itself to dual channel if you use pairs of identical memory.

The answer is "42"

 

[cdogg]

Glenn,
Except for Dakota's 2nd post which said:

I have just noticed that my BIOS now says I only have 2GB

Even though Windows may or may not report the correct amount, the BIOS should.

~cdogg
"Insanity: doing the same thing over and over again and expecting different results." - Albert Einstein
[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884

 

[stduc]

The test of my first stick of RAM in slot 1 is now executing, however will I have to test each stick of RAM in EACH slot, or can I just test 1 stick in all slots, and then only the remaning sticks in the 1st slot?

Basically - yes that will do. If the board accepts 1 stick in any slot.

You can leave letting memtest86 to run through till later if you are impatient. Just check that memtest86 can 'see' whatever you have installed. Once the BIOS & memtest86 see 4GB then you know you have a windows issue.

I would recommend a run of memtest86 through the whole 4GB though when you can find the time (overnight?)

 

[SeanGilbreth]

Thank you again everybody for your continuing support. I will try a MemTest overnight tonight (8:31 GMT here), with my 4GB. In the meantime, are there are other things I could try?

 

[SeanGilbreth]

I have a theory that this problem may have something to do with lack of power to the memory slots. When I first said I remember seeing the BIOS list 4GB of memory, it was with my previous PSU, but I changed it about 6 months later to a more powerful one, and I didn't check if 4GB was still listed until yesterday when I noticed the problem. Could it be that maybe I haven't fully connected all of the cables I need to when I changed PSUs? I've looked everywhere on the motherboard for a power plug near the RAM slots, but I can't find one.

Also, my DRAM Power LED is light orange colour, maybe this is an indication?

 

[SeanGilbreth]

Wow! I activated something called "Memory Hole for PCI MMIO" and now the BIOS and Windows now say I have 3.5GB! However, for some reason, the sound coming from my speakers is EXTREMELY crackly and unbearable, and I still don't have the full 4GB. Any more suggestions?

 

[Sympology]

Do you have an internal Video card? This may be eating up some of your memory, but 512mb may be a bit two much !

Stu..

Only the truly stupid believe they know everything.
Stu.. 2004

 

[wahnula]

Wow! I activated something called "Memory Hole for PCI MMIO" and now the BIOS and Windows now say I have 3.5GB

This is one of the BIOS features I had to reset to get my full 4GB visible in BIOS & Windows after enabling Physical Address Extension. Strange, with BIOS defaults loaded all 4GB should be visible in BIOS. If BIOS cannot see it Windows won't either. What exactly did you do between your first and second posts???

As a note for the future, when troubleshooting write down all changes you make to the system. Took my mentor a year to get me to do it, but now it is second nature. Makes backtracking easier.

Tony