Will a Gfx card limiy windows memory?

Keltik THC · 5 Feb 2009 at 09:23

reflux said:
It doesn't affect your graphics RAM at all. It eats into the system RAM. Thus, with two 280s, and 3GB of RAM, on a 32-bit OS, you will only see 1GB of system RAM.

I'd quite like to see what would happen on a 4GB system with two 4870X2s, both with 2GB of RAM each. Would the OS even boot, with no system RAM available?

im wondering if Vista 32 will even work with 2x GTX 280s and 3GB DDR3, i ordered another 280 the other day and it should be with me before the weekend weather permitting... i mean im sure Vista uses like around 40% of ram without gaming as it is.

Although, my system still shows 3GB of DDr3 when i have one 280... i thought according to some of you guys it would only show 2GB of system RAM with the other 1GB being taken up by my GPU?

EDIT: Excellent news, my colleague at work just told me he has a spare copy of Vista 64 that he doesnt use and he will even give me CD key for it.... at least i dont have to chase up microsoft looking for my free upgrade... now once i have this in my hand next week ill just have to hope and pray that all my drivers work on Vista 64 (g15, Lachesis, Cisco Wireless USB stick, Medusa 5.1 headest etc..etc..)... if not then im in a bit of a conundrum which would be to stick with 32 bit and loose 2GB of system RAM out of 3gb and have all my perhiperals and software working fine or go to Vista 64 and have 3GB ddr3 + 2gb of GPU RAM but have issues with my prehiperals and software

... fingers crossed it all works out well, if not im going to be unhappy for a long time... i would feel better if the my other colleague at work would stop constantly telling me i should have bought a Mac lol.

Sweetloaf · 7 Feb 2009 at 09:02

Keltik THC said:
Although, my system still shows 3GB of DDr3 when i have one 280... i thought according to some of you guys it would only show 2GB of system RAM with the other 1GB being taken up by my GPU?
.

This is now confusing me, If Windows 32bit can see 4Gb and my GfX card is 512mb then where has my other 0.5Gb gone?

Even with a 1Gb card I should be able to utilise 3Gb system RAM.

mame · 7 Feb 2009 at 09:51

There is other things that use small amounts of memory e.g. sound (on-board or card)

Sweetloaf · 7 Feb 2009 at 09:53

mame said:
There is other things that use small amounts of memory e.g. sound (on-board or card)

True but where is my other 512mb hiding? I don't use onboard sound and isn't a graphics card aperture a thing of the past that died with AGP?

Fire Wizard · 7 Feb 2009 at 11:16

The maximum amount of address space a 32-bit system has access to is 4GB and within this both your physical memory plus other critical functions that also need to map there memory resources into this space such as System BIOS, configuration for PCI/PCI-Express and any other memory mapped I/O functions such as your graphics card. These functions take priority over your physical memory which means they are all mapped first so if for example these functions take up say 1.5GB, it means that the address space is then cut down to 2.5GB which will then result in the system only being able to address 2.5GB of physical memory.

One of the main functions that result in this inaccessible space is due to your graphics card. The graphics card needs to map a large portion of its memory resources into the address space. It is dependent entirely on your system configuration, this is why it varies from one machine to the next and there is no set number.

Sweetloaf · 7 Feb 2009 at 12:28

Fire Wizard said:
The maximum amount of address space a 32-bit system has access to is 4GB and within this both your physical memory plus other critical functions that also need to map there memory resources into this space such as System BIOS, configuration for PCI/PCI-Express and any other memory mapped I/O functions such as your graphics card. These functions take priority over your physical memory which means they are all mapped first so if for example these functions take up say 1.5GB, it means that the address space is then cut down to 2.5GB which will then result in the system only being able to address 2.5GB of physical memory.

One of the main functions that result in this inaccessible space is due to your graphics card. A large potion of the amount of memory the graphics card has access to is mapped into the address space. It is dependent entirely on your system configuration, this is why it varies and there is no set number.

Ok so If I did upgrade to a 1Gb graphics card is there a way of configuring things that means I will not lose 512Mb system RAM?

-)G(-Sawyer · 7 Feb 2009 at 12:47

Sweetloaf said:
Ok so If I did upgrade to a 1Gb graphics card is there a way of configuring things that means I will not lose 512Mb system RAM?

No, 64bit XP or Vista is the only way to use 4GB or above of ram.

Fire Wizard · 7 Feb 2009 at 12:52

Sweetloaf said:
Ok so If I did upgrade to a 1Gb graphics card is there a way of configuring things that means I will not lose 512Mb system RAM?

Nope, I'm afraid there isn't. If you want to be able to address all 4GB of RAM, you will have to upgrade to a 64-bit operating system which I don't see why people are still against it. When Windows Vista was first released to the public, driver support was slightly below par and there were maybe compatibility issues with certain pieces of software but today, you shouldn't have a problem.

There are other advantages to 64-bit too which you can read about in this article here 64-bit: More than just the RAM by Bit-Tech and a post here written by NathanE.

Stormrider · 7 Feb 2009 at 12:54

What's with the 3Gb memory barrier?

Power users with a hankerin' for dual graphics cards may be experiencing something of a sinking feeling, at this juncture. Yes, the 256Mb reserved for my little old graphics card means exactly what you think it means: Those two 768Mb graphics cards you can totally justify buying will eat one point five gigabytes of your 32-bit memory map all by themselves, cutting you down to a 2.5Gb ceiling before you even take the other reservations into account.

R.O.S.S.I · 7 Feb 2009 at 13:50

Hi all, sorry to hi-jack this thread.

I've just bought a new quad core setup, Q6600, 4gb ram and mobo.

To use with it I have my 7800GT 512mb. Now I know 32bit XP will only see 3.5GB max. and with the 512mb of my gfx card chompin anyway at my RAM, I should be seeing 3GB.

However, when in Windows and I right click on my computer to show the computer details, it is only showing as 2.5gb of RAM? Does anyone know why this is? Because by my reckoning it should be showing 3gb at least?
The RAM is definately working fine as it is brand new, and is showing up as 4gb on POST.

Is there anyway I can find the missing 0.5GB of RAM, or am I best just sticking Vista 64bit on?

TheVoice · 7 Feb 2009 at 14:34

Keltik THC said:
...ill just have to hope and pray that all my drivers work on Vista 64 (g15, Lachesis, Cisco Wireless USB stick, Medusa 5.1 headest etc..etc..)... if not then im in a bit of a conundrum which would be to stick with 32 bit and loose 2GB of system RAM out of 3gb and have all my perhiperals and software working fine or go to Vista 64 and have 3GB ddr3 + 2gb of GPU RAM but have issues with my prehiperals and software :

If it's recent hardware, there should be decent 64-bit drivers available. Easy enough to check anyway, the relevant manufacturer websites will tell you.

Sweetloaf · 7 Feb 2009 at 15:36

-)G(-Sawyer said:
No, 64bit XP or Vista is the only way to use 4GB or above of ram.

That's not what I asked, I mean that I have 4Gb RAM a 512Mb Graphics card and windows is showing that I have 3Gb which leaves 512mb unaccounted for as was said earlier this is reserved for various thing and is different from sysytem to system, I wanted to know if I could free up some of that hidden 512mb. I don't quite understand where that is being used to be honest.

Fire Wizard said:
Nope, I'm afraid there isn't. If you want to be able to address all 4GB of RAM, you will have to upgrade to a 64-bit operating system which I don't see why people are still against it. When Windows Vista was first released to the public, driver support was slightly below par and there were maybe compatibility issues with certain pieces of software but today, you shouldn't have a problem.

There are other advantages to 64-bit too which you can read about in this article here 64-bit: More than just the RAM by Bit-Tech and a post here written by NathanE.

I use a plethora of old VST plugin instruments, Ableton Live, Cubase SX3 etc etc a lot of which still have issues with Vista or just simply won't work at all.

Also it's £90 I don't really feel the need to spend, It's not like I need that extra RAM at the minute for that matter I don't need a new graphics card, I just want to be prepared that's all.