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64-bit system not recognizing all memory.

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March 10, 2008 3:17:13 AM

Basics:
Home-built system with MSI K9A2 Platinum board and 4Gb of OCZ SLI-Ready Memory.
Running Vista Ultimate 64-bit.

Every other start reads 4.00Gb like it should, and the other alternating starts show 3.25Gb.
Not sure why yet, been trying to see if I'm missing any hardware updates, or if my memory timings/voltage aren't correct.

I pumped up Memory voltage to 2.25 from 2.1
Timings are 5-5-5-15 at the moment.

Still doing this.
I'm confused as to why.

This is almost a $2000 high end system, and I was going to pump in another $110 for more OCZ Reaper Memory (to have 8Gb. But I'd like to know if I can actually use it first.

So.
In recap:
64-bit OS:
4Gb of OCZ RAM onboard MSI K9A2 Plat.
alternating restart show 3.25 and 4.00Gb of RAM
Voltage has been pumped up some, and timings looks correct in BIOS.
March 10, 2008 4:00:16 AM

Why did you "pump up" the voltage?
Run memtest.
March 10, 2008 5:02:47 AM

Bios... some memory remapping stuffs must be enabled so that the 4GB will be recognized. Since 4GB is the maximum RAM for most chipsets but complexity involve you need to change bios settings to make it succeful. Search some related threads about this if you get confused.
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March 10, 2008 5:56:00 AM

pogsnet said:
Bios... some memory remapping stuffs must be enabled so that the 4GB will be recognized. Since 4GB is the maximum RAM for most chipsets but complexity involve you need to change bios settings to make it succeful. Search some related threads about this if you get confused.


According to MSI, your MB should support up to 8GB of memory.
I tried to download your MB's manual to check if there's a memory re-mapping function.
But something's wrong with their servers and I am unable to download it.
What you should do is check whether the memory re-mapping function is on!
According to x64 OSs, this shouldnt be an issue at all when recognizing all 4GB of memory.
From what I understand, the memory re-mapping works together with a x86 OSs which has a MAX 4GB physical memory limit:

(1) when turned on, memory allocation of hardwares (sound card, graphic card, etc.) are re-routed so the maximum system phsical memory (4GB) is shown.

(2) when turned off, the memory allocation of hardwares (sound card, graphic card, etc.) takes up a few hundred MBs of the 4GB memory OS allows and hence people usually see only 3.25 ~ 3.5GB with 4GB installed!

I run 4 x 2GB on a MSI P35 Neo2 FIR with Vista Ultimate 64.......no problems
My motherboard's BIOS dont have a "memory re-mapping" function so I guess its automatic or some say the function is actually enabled / disabled with CPU settings in the BIOS.
Either way I see all 8GB in BIOS and in the OS.

I guess checking the OS version to make sure it is 64bit is another option (a stupid suggestion I admit).

Anyway, good luck.............

If you get it up and running, I tried turning off the paging file and it does seem to respond smoother even when multiple memory hungry programs are running!!!
March 10, 2008 2:08:46 PM

gh0st - I did that because I read somewhere that without enough voltage (and some mobo's don't give enough by default) it won't read all of it, I didn't think it'd work, but hell, you gotta try before you know.

pogs - As gudodayn says, the mobo should automatically be able to handle up to 8Gb.

Gudodayn - Thanks for the thorough reply.
Although didn't help much. I read through the mobo manual front to back before I posted. Saw nothing about this. I'll re-check for another "re-mapping function" in the BIOS, but I didn't see one the first few times I've been in there.

And yes, I know for an absolute fact I have 64-bit OS, mostly because half of the stuff I'm used to having on 32-bit OS won't freaking work for me. :/ 

Other than that, the system is blazing, (well one other minor glitch with the mouse) and I'm happy.
March 10, 2008 3:36:59 PM

Not to detract from the suggestions given here but have you contacted OCZ Tech support?

Amazing bunch there!
March 14, 2008 5:46:11 PM

Alright - ran Memtest and DxDiag.
Both return normal results, and show no errors.
DxDiag also shows 4Gb of RAM installed.

Cannot find any option in the BIOS like that for the memory.

Remember, the system on every other restart shows 4Gb, and the ones it doesn't show 4Gb - it shows 3.25Gb.

I will probably contact OCZ or MSI support soon, if this problem doesn't go away.
!