Where's half or my memory?

[windyweather]

I've got an Alienware Aurora R2, with 8GB installed, but only 4GB showing up.
Running Windows Home Premium x64.
Windows says I have 8GB, but only 4GB is usable.
What gives?
Where's the "Use Half My Memory" switch in windows so I can turn it OFF!!!


Here's the details: as CPU-Z Screen shots.

Thanks,
ww

 

[ATMINSIDE]

Dedicated or integrated GPU?

 

[windyweather]

Nvidia 560 Ti

It has 2GB memory. So uses none - minimal - of main memory, Right?
- ww

 

[ATMINSIDE]

Its taking 1787MB of your system RAM. Says 1GB dedicated 1.7GB shared.

So, there's part of it.

Have you run Memtest?

 

[windyweather]

No. How do I run memtest?
Also, BIOS shows 4096 "installed", 4088 available. But then on memory pages it shows all 4 DDR3 modules, 2GB each. I don't see errors from BIOs saying 1/2 the memory is bad.

I'll google for memtest.
- ww

 

[ATMINSIDE]

Did you add the memory in or did it come with 8GB from the factory? It might be that 8GB isn't supported by the motherboard.

You'll need a bootable USB stick with Memtest86+ on it. Yumi Multiboot can do it for you.

 

[windyweather]

I found a way to run a memory test using windows.
Restarted into the memory test, ran standard 2 passes. When it rebooted, it said that no errors were found.

I bought system used, but it was not modified by previous owners, so it came this way from Alienware, although I don't know how long it has shown only 4GB.

So, Part of BIOS thinks theres 4GB, and the advanced settings shows 8GB.
Windows says 8GB are there, but 4GB are "Usable".
Windows Memory test shows no errors.
The Core i5-750 does not have an onboard GPU, so it shouldn't be stealing RAM for that.

Sigh.
- ww

 

[windyweather]

Windows Memory test was no help. It passed, but it only checked 4GB of memory:

- System

- Provider

[ Name] Microsoft-Windows-MemoryDiagnostics-Results
[ Guid] {5F92BC59-248F-4111-86A9-E393E12C6139}

EventID 1101

Version 0

Level 4

Task 0

Opcode 0

Keywords 0x8000000000000000

- TimeCreated

[ SystemTime] 2013-07-30T02:46:28.620125500Z

EventRecordID 174398

Correlation

- Execution

[ ProcessID] 3920
[ ThreadID] 3928

Channel System

Computer Alien-Aurora

- Security

[ UserID] S-1-5-18


- UserData

- Results

LaunchType Manual

CompletionType Pass

MemorySize 4087

TestType 10

TestDuration 514

TestCount 12

NumPagesTested 1045199

NumPagesUnTested 1093

NumBadPages 0

T1NumBadPages 0

T2NumBadPages 0

T3NumBadPages 0

T4NumBadPages 0

T5NumBadPages 0

T6NumBadPages 0

T7NumBadPages 0

T8NumBadPages 0

T9NumBadPages 0

T10NumBadPages 0

T11NumBadPages 0

T12NumBadPages 0

T13NumBadPages 0

T14NumBadPages 0

T15NumBadPages 0

T16NumBadPages 0

 

[windyweather]

Added BIOs screens to the photos.
Thanks,
-ww

 

[ATMINSIDE]

Pull the memory out and reseat it.

 

[windyweather]

Reseated, and Swapped around the rosy.

Pull the memory out and reseat it.

Done. Swapped them all around. That's how I found out that the BIOs sees 2 DIMMs as 1/2 of that or 2GB out of 4GB. The white slots [nearest CPU] don't work with either pairs of DIMMs. But the black slots work with either pair. If only the white slots are filled, the BIOS will never come up. The system just hangs.

I assume this is due to the need to have the black slot channel filled first.
If we guess that one of the white dimm slots is bad, that would not account for the fact that the BIOs sees 2GB out of 4GB when the black slots are filled.

- ww

 

[ATMINSIDE]

Definitely seems like the issue is some of the slots not reading right if both pairs work in the black slots.

Do you have another system you can try all four sticks in?

 

[windyweather]

I tried all 4 DIMMs in another system and that system shows 8GB both in BIOS and in Windows with no "Usable" qualifiers. So looks like all the DIMMs are good.
Also, since BIOS does see all the memory [in the advanced pages of BIOS, all 4 DIMMs show up] and since if we put only 2 DIMMs in the system, the BIOS shows 2GB rather than 4GB like it should, can we conclude that it's not a problem with the DIMM MB slots?

So, we are back to some invisible BIOS setting or to some jumper on the Alienware MB that is reserving memory? Maybe for that old AMD GPU that was in the system when I got it.

System just locked up as I was entering this post. Sigh... Maybe time for an upgrade.

- wg

 

[ATMINSIDE]

Can you clear the CMOS on that Alienware?

 

[windyweather]

I set a Set Defaults in the BIOS. is that what you mean?
I have read the BIOS section of the manual that came with the system and it is no more enlightening than the BIOS itself. No note on how to Clear the CMOS.
At this point I have little to lose by "Resetting to Defaults" in the BIOs, so I guess I'll try it.
Back shortly one way or the other.

No joy in setting defaults. No change.

- ww

 

[insanemonkey]

Try turning off the system, unplugging the power cable, and then removing the CMOS battery. Let it sit for 10 min then plug everything back in.

 

[windyweather]

I found a MB manual online. Who knew. It pointed out that the CMOS battery was under the GPU PCI-e slot. When I removed the GPU, I found a jumper that said to move the Jumper to reset the CMOS. Which I did and....... While the CMOS was reset and I did need to reset the boot sequence, there was no change in the problem. Still have 4GB of memory visible to windows while the BIOS sees all 4 DIMMs.

No joy in CMOS reset.

Do we know whether 8GB are in fact supported by this BIOS? Maybe this MB predates the actual shipping of more than 4GB systems by Alienware / DELL. I went round and round with Alienware in the 2006 timeframe with my AW Area 51, but now have it running 8GB [ for real ] and Windows 7 X64 [which AW did not support at the time.]. Are we looking at a system that has been locked down to 4GB max, even tho it was shipped with 8GB?

Anybody sighted a 2010 Alienware Aurora R2 systems running more than 4GB in the wild?

- ww

 

[ATMINSIDE]

You'll have to get some motherboard details for us. What's CPU-z say?

 

[windyweather]

All the details are at the collection from the first post.

Thanks
ww

 

[ATMINSIDE]

My bad, missed the mainboard picture in that.

Not finding much about it. Is there a brand/model printed on the board itself?