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Just remember to differ between virtual addressing and the pagefile. Two different things. :-)

Before SP2, XP could make use of more than 4 GB address space with PAE, so you could get 4 GB usable system ram. But only up to 4 GB usable, so they don't want non-server editions to go beyond 4.

I still use an old 16bit app. That needs 32bit Windows. I have just chosen to run it in a virtual machine.

If you want to overwrite the entire drive, just run diskpart during setup. It has the option to do it.

Then you will have to download Linux. The necessary tools are included with Windows. So I don't know if it is the best one.

Intel calls it "compatibility mode", and instructions are executed directly by the hardware

#4 It is smart enough to create two mappings. The lower part will run in dual channel mode. Intel calls it flex mode.

That is just a myth. You cannot hardcode your application to do that.

Sometimes exaggeration makes the point more clear

That is not given. Commited memory just means that it is available to the application. It doesn't necessarily mean that physical memory has been assigned. If I commit 10 GB, but only use 512 MB then only 512 MB physical ram is used.

It is something with chains and weak links...

Why do people insist on that the page file is still there and data moved out to it when it is disabled? :)

It doesn't do that now. Applications cannot reserve memory in the page file. If an application checks if there is a page file, it might be out of fear of running out of memory.

The system ram is not being used, it cannot be used, because the cpu has no way of addressing it. It can only be addressed after remapping - that is why remapping was invented. I am not sure we're on the same page. I never said such a thing. I keep saying the address space is being used (mmio)...

Look at it again. It has two areas with mmio. One below 4 GB and one below 64 GB. The traditional mmio is not moved. It is still located below 4G. Look at how the ram is remapped (reclaim base). No, and btw, if you look at the map you'll se "OS Invisible" in the overlapping area with mmio...

Unless it uses tricks :)

No, the address space is used. The RAM is not. I said in a previous post not to confuse mmio with dma. You see all of it in x64 Windows, because you have a much larger address space. If the ram was actually reserved for use with dma and such then it would also be gone in x64.

About making it easier for programmers... they don't really care about it. It is all handled by the OS. You are right in one thing: If your amount of ram equals the size of your total address space then you have a problem, because you need empty space for remapping.

Okay, let us review what Intel says: "The (G)MCH provides the capability to re-claim the physical memory overlapped by the Memory Mapped IO logical address space. The (G)MCH re-maps physical memory from the Top of Low Memory (TOLUD) boundary up to the 4 GB boundary to an equivalent sized...

In your first reponse you said that the memory was actually being "used". That is still wrong. I have never said that mmio has no address space. I said that the missing ram has no address space (therefore it is not used). Look up memory remapping in any hardware reference manual at amd.com or...

Remapping doesn't actully move the mmio area (it stays below 4G), it moves the overlapped system ram up above 4G.

The ram that is hidden behind mmio has no cpu address space, hence you cannot use it. It is as simple as that. Memory remapping fixes that - in conjunction with an OS that goes beyond 4G. If you write to a mmio address that points to vram then you write "directly" to the vram, your system ram...

So you agree that this statement is faulty? In order to "use" the ram, you need to assign address space to it - which you cannot do when Windows doesn't allow access to address space above 4G.

They are the same, they share the same physical address space. The part with MMIO cannot be used by ram, so it is therefore not used (wasted).

I don't think that makes it any more clear, because it doesn't use all the installed ram. It is ram vs address space.

Use TrueCrypt.

Still there are computers with 64bit CPU+OS which cannot address anything above 4G.

The shared graphics memory is not reserved, so everybody can use it.

You can control it a little bit

If my point is not clear: The issue with hardware not being able to do 64bit-addressing is the same whether you install a 32 or 64bit OS. Double buffering will be needed in both cases - which is handled by the OS.

If the developer wants it to, it can trap just as fine as the 64bit OS can. The problem doesn't change just because you install a 64bit OS. The same goes for a 64bit OS.

Yes, the driver tells Windows that the card cannot do 64bit-addressing. That same goes for at driver in 32bit Windows. If addressing above 4G is needed then the OS does its magic...

Well, that is not an excuse, because there are workarounds to that - which are also needed by a 64bit OS.

Well, what a waste of ram and money.

Did you even try to understand? It seems you don't understand the difference between the term "RAM" used in that wiki article and what DRAM is. It is really not the same thing. All your talk about MMU, page tables and virtual memory in this debate makes you look like a noob. Sorry.

Try and understand that the CPU and MMU as such has nothing to do with the memory controller. The memory controller is the link between your DRAM and the rest of the computer. As said, picture an older cpu - that will make it easier for you. The memory controller in the northbridge is what...

This is a waste of time.

You should ask yourself that. Or try and think on an older cpu where the memory controller is not embedded inside it. What name will you give the address lines coming out from it?

You are a funny guy. If the address space (in this context) was defined as the space between the memory controller and your ram - then how can an address point to something not in ram?

Address space is just an empty space initially. A bunch of address lines going out from the CPU. The address space is populated with RAM and MMIO. His problem was a shortage of address space (the maximum memory setting in Windows). He only had 4GB address space. That is not enough for both...