64-bit vista not recognizing all four gigs?

So I installed Vista Ultimate 64-bit, because it's supposed to recognize all 4 gigs of RAM.

In system information, Vista's task manager and sidebar RAM meter, it only seems to recognize 3.25 gigs.

Help with getting it to recognize all four gigs would be greatly appreciated.

 

Some BIOSes can't handle 4 gb. Make sure you have the latest BIOS update from your manufacturer. What computer is this?

 

Some chipsets cannot handle more than 4GB of RAM either. What chipset do you have?

 

Custom PC.

The motherboard is ASRock x48 TurboTwins WiFi.

My BIOS does recognize all four gigs.

Intel X48, I think.

 

Do you have vista SP1?
If not then it may only be showing the ammount you have available.
Your graphics card is probably running off shared memory so you don't have as much to use and vista without the updated sp1 won't show it.


*Oooops... Disregard this post I didn't see in your screenshot that you did have sp1*

 

I am running Vista Ultimate SP1 and I have 512MB of dedicated VRAM, so I doubt that it would be taking any shared memory.

Edit: Sorry, I posted before you edited. But it's all good.

 

See if there is a Memory Remap or H/W Memory Hole feature in the BIOS. If so, try enabling it, and see how much memory Vista shows....

 

Windows did recognize it all. It's showing total physical memory 4GB. You have 3.25GB because the rest is used to map all the other components, including your video card. Although you have dedicated memory, Windows still reserve some space on the memory to keep track of what's in the video card memory on the system memory. Infact, if you have integrated memory, you'll probably see more available memory.

 

That answer is correct for 32bit version not 64bit version. 64bit does not have 4GB memory address limit you speak of?

So How do we know you have 64bit version? Could it be 32bit?


This from your chipset specs, link.

What does this mean? Not sure I have read ten times. But look at the "bold" is reclaim disabled? That would explain I think? Can you control that in BIOS? Is it set when chipset put in MoBo? I don't know.

This is way over my head just guesses. But it reads like it would explain a 4GB memory address limit from the chipset not the OS. Making it look and read like exactly like a 32bit OS for reported usable RAM.

Any computer scientists "almost" (Greg) that can make heads or tails of this?

 

He has 4GB total physical memory. So I'm not sure what limit you are talking about. Windows is seeing all the memory, only that "available" memory is showing less than 4GB. I would assume that's because of the other peripherals that he has on his system.

 

4GB is the physically installed memory. Not necessary that the whole 4GB is addressable. Though Intel does state that the X48 can address upto 8GB. Since the OP has a custom notebook, it is worth checking out the BIOS for remap options.

 

Under a 64bit OS, the memory mapping problem (which is what limits 32bit OS to < 4GB) is no longer a problem.

Some RAM will take up memory addresses 0-~3.5GB, then system devices take addresses ~3.5GB-4.0GB, and then the rest of the memory takes 4.0GB-~4.5GB.

In a 64bit OS, which supports up to 2^64 memory addresses (that's a lot!) there is no problem asking about address 4.5GB and thus your RAM should be accessible.

In a 32bit OS, any address higher than 4.0GB cannot be addressed (2^32 = 4GB) as there are not enough bits to go around. Which is why you get less than 4GB of RAM on a 32bit OS.

Sheesh...quick lesson in memory mapping for the forum!

Anyway, being able to address anything > 4.0GB requires (1) chipset support (it has to have enough address PCB traces and pins available), (2) motherboard support (manufacturer has to actually run more than 32 lines of address space), (3) BIOS support (I/O of system needs to know 64bit is available otherwise nothing works), and (4) OS support (software needs to know that 64bit addressing possible).

If any one of those four things is missing...BOOM! You can only have ~3.5GB.

 

I am confused. If I am not understanding you and saying things you are aware of I apologize. But I think I understand you so want to inform you. And just noticed you have 64bit OS and 3.25GB's RAM?

Windows sees all the RAM? Yes the BIOS sees 4GB's Windows reads and reports 4GB's. RAM is fine. "Available" under reported? Standard for 32bit OS with 4GB's. Why? 2^32 just happens to equal 4GB's. Coincidence? No. That is the maximum amount of "memory addresses" not the same as RAM/memory. But RAM must use those "memory addresses" to function.

The devices you mention are not using the RAM per se. They are using the "memory addresses" that RAM must also use. If the total amount of "memory addresses" is 4GB's and you have 4GB's RAM? The devices cannot use the "memory addresses" they need (not RAM must make very clear) because RAM is using all.

What happens is the devices use the "memory addresses" for I/O then leaving less than 4GB's remaining for use by RAM. One of the main benefits of a 64bit OS is the ability to use more RAM because the "memory addresses" are know 2^64, a very much larger number I can't explain well now but trust me. Not double, exponential. Windows 64 can use up to 128GB (certain versions) but consumer chipsets I believe are limited to around 16GB's. Those are "memory addresses" not RAM.

So remember some hardware uses "memory addresses" for I/O operations. RAM uses those same "memory addresses" to function. They cannot share. If one must use the other cannot. This cannot be changed on the fly or hot swapped or dynamically switched or whatever term makes sense to you.

I hope I made some sense? If not post back and will consider deleting as off topic for OP.

 

Thanks for your help, guys. I guess I'll just check each of the four things Greg said and see if it works.

 

No, you guys are missing my point. Look at my screen grab of the "System Information"...now I have 4GB installed, but Windows only recognized only around 3.3GB. That's because I'm running pre-Santa Rosa chipset, so my system is limited. Look at my available memory. Much less than 3.3GB. Now look at his screen grab, under Total Physical Memory, he has 4GB. That's what I'm talking about. That means Windows recognized all of his 4GB. Although only 3.25GB is available.

Granted, it could be Vista (where even 32-bit system would show all 4GB available), I'm running XP64. Either way, the only way to really know how much memory Windows is seeing is to get the screen grab of the task manager. Mine is included below.

 

Weird that MSinfo32 on your system is not showing the "Installed Physical Memory".

Anyway, (Total Physical Memory) - (System Cache) = (Available Physical Memory)

 

My chipset limitation will not allow it to recognize anything more than that. This is another limitation that they're referring to. Anything before Santa Rosa for Intel chipset, I'm not sure what it is for AMD.

 

Windows Vista/XP will recognise the total amount of memory installed. Well, you can verify that in CPU-Z. It just gets that info from the registry that is linked with the BIOS of your system.



OP: Check in Msconfig > Advanced Options > Maximum Memory ?

View attachment 24757

 

If it helps, here's my screenshot of task manager. Again, about 3.3 gigs. My computer is a desktop, not a laptop and I don't think I should be limited by my chipset of BIOS.

 

Thanks for all your help guys. I changed a setting in my BIOS and now all four gigs are usable.

 

It might cause driver issues, and if it does you can disable the memory-mapping in the BIOS.

 

It's not vista. The problem is he has a 64 bit processor but the chipset is not true 64bit. The chipset is the limiting factor here, not the O.S. or the processor.