Sapphire Radeon 4870 X2

[Zinos]

your test system has 4gb of ram. a 32bit os no matter what it is can only access 4gb of ram. your video card has 2gb of ram. that equals 6gb of ram. so how can the os access all that ram when it can only see a max of 4gb? all im saying is it is time to upgrade your os for testing.

Notice the formatted text in my quote. The card doesn't have what is considered system ram, it has VRam.

Vram and System Ram are 2 completely different things that are accessed and recognized completely differently in a Windows based operating system.

[trick0502]

Notice the formatted text in my quote. The card doesn't have what is considered system ram, it has VRam.

Vram and System Ram are 2 completely different things that are accessed and recognized completely differently in a Windows based operating system.

no they are not two different things! ram is ram no matter what it is on.

[Zinos]

Wrong.

It runs on a dedicated memory bus from the GPU to the VRAM, so it is not subject to the machines memory controller and contention from all the other RAM accesses of the computer.

the fact that the graphics card has DEDICATED VRAM means that it will use that VRAM first before looking to the system's RAM for help.

Ideally, you use your system RAM for your OS and applications, and let the GPU use it's own VRAM.

Two completely different things.

[trick0502]

so what your saying is you could have 4gb of system ram, 2gb of gpu ram, 128mb on your sound card and 128mb on a phys card? something has to give...

[Zinos]

Nothing will give. System RAM is the only thing accessed, recognized, and limited by a 32-bit operating system. Other types of RAM on video cards, sound cards, physics cards; caches on hard drives, etc. are all dedicated to that specific device.

[trick0502]

so you can have a gpu with 8gb of ram on a 32bit os?

[trick0502]

http://support.microsoft.com/kb/929605/en-us

Various devices in a typical computer require memory-mapped access. This is known as memory-mapped I/O (MMIO). For the MMIO space to be available to 32-bit operating systems, the MMIO space must reside within the first 4 GB of address space.

For example, if you have a video card that has 256 MB of onboard memory, that memory must be mapped within the first 4 GB of address space. If 4 GB of system memory is already installed, part of that address space must be reserved by the graphics memory mapping. Graphics memory mapping overwrites a part of the system memory. These conditions reduce the total amount of system memory that is available to the operating system.

The reduction in available system memory depends on the devices that are installed in the computer. However, to avoid potential driver compatibility issues, the 32-bit versions of Windows Vista limit the total available memory to 3.12 GB. See the "More information" section for information about potential driver compatibility issues.

If a computer has many installed devices, the available memory may be reduced to 3 GB or less. However, the maximum memory available in 32-bit versions of Windows Vista is typically 3.12 GB.

Can i get some thanks??? so your 4gb system with 2gb of gpu ram is really only running with about 2gb of ram on a 32 bit os.

[Doctor_Death]

so you can have a gpu with 8gb of ram on a 32bit os?

There's no way 8gigs of memory is showing on a 32 bit OS, you have to have a 64bit OS.

I

[Zinos]

http://support.microsoft.com/kb/929605/en-us

Can i get some thanks??? so your 4gb system with 2gb of gpu ram is really only running with about 2gb of ram on a 32 bit os.

In gaming scenarios, the Vram is what is being utilized. The 4gb of System RAM is never really touched. Thus, you still have 4gb of System RAM avail for other things while gaming.

[trick0502]

oh so now your saying i'm right?

[trick0502]

In gaming scenarios, the Vram is what is being utilized. The 4gb of System RAM is never really touched. Thus, you still have 4gb of System RAM avail for other things while gaming.

your so wrong!! you may have 4gb of system ram, but with the 4870x2 you really only have about 2gb of system ram on a 32bit os.

[Zinos]

your so wrong!! you may have 4gb of system ram, but with the 4870x2 you really only have about 2gb of system ram on a 32bit os.

In every day computing? Yes. 4gb is the max you can have on a 32-bit operating system. In gaming? The system RAM isn't affected as it uses the 2 gb of VRAM on the card, leaving the 4gb of system RAM available for out-of-game computing. That is why VRAM is DEDICATED to the CARD. If you have a 64-bit operating system with 8 gb of system ra and 2 gb of VRAM the computer DOESN'T SHOW 10gb of RAM. If it's seperate on a 64-bit operating system, it's seperate on a 32-bit operating system. Two. Different. Things.

Here is why they are seperate and why the operating system does not recognize them both, collectively, as RAM.

This is using a 64 bit operating system scenario: (To prove that both are recognized differently)

Gaming: If somehow he uses the 2gb of VRAM DEDICATED to the graphics card, then the rig will start to dip into the SYSTEM RAM.

Other applications: Say he runs out of that 4gb of SYSTEM RAM then if it were ALL recognized as RAM he could dip into the 2gb on the card, the 128mb on the sound card, etc. Well... he can't. Why? because they are different things.

VRAM is ONLY accessed when gaming or doing other graphic applications.

While gaming, RAM isn't accessed UNLESS it's used all of the VRAM DEDICATED to the CARD.

Show me exactly how this is wrong. If you can show it to me, I will gladly tip my hat to you and be happy that I learned something. Otherwise, this is as far as I can go.

[trick0502]

did you read this?

http://support.microsoft.com/kb/929605/en-us

"For example, if you have a video card that has 256 MB of onboard memory, that memory must be mapped within the first 4 GB of address space."

the gpu ram gets mapped first.

[Zinos]

did you read this?

http://support.microsoft.com/kb/929605/en-us

"For example, if you have a video card that has 256 MB of onboard memory, that memory must be mapped within the first 4 GB of address space."

the gpu ram gets mapped first.

"Note Windows Vista Service Pack 1 (SP1) changed how components of the user interface (UI) report memory."

My hat is tipped to you. I've been without a rig since before then.

In fact, I have yet to own Vista. I owned 64-bit XP and Mac OS X on my X6800 rig.