I figured after everyone had the 2GB limit problem with XP that they would FIX it with Vista, but I guess I thought wrong! I have 4GB and Vista only sees 2GB!! What is wrong with Microsoft?? 
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Mac Pro + Vista Business = only 2GB of RAM???
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Eh? 3GB, but still.
Is there a solution to this? I have 32-bit Vista Business edition, and 4GB of ram. It sees all 4 cores, but only 2 of my 4GB of ram.
Is there a solution to this? I have 32-bit Vista Business edition, and 4GB of ram. It sees all 4 cores, but only 2 of my 4GB of ram.
I have vista ultimate, and like you it only see's 2gb of memory in system profile.
MacPro 2.66. 5gb Memory..
MacPro 2.66. 5gb Memory..
to get full access to 3GB or all the memory in windows you need either the /3GB switch (not got vista but in xp its added in the boot.ini) or the 64bit version. If youre running a 32bit os, it will allocate 2GB to programs and then 2GB to the os without the switch when theres 4GB for example
That is messed up. I know a few people that brag about having 4 GB on their Windows boxes too. They have no clue about any setting or switch.
Anyways, I brag back to them about my 8 GB and having a real OS. But I don't have any programs that can use more than 2 GB.
Anyways, I brag back to them about my 8 GB and having a real OS. But I don't have any programs that can use more than 2 GB.
The 3G switch only allows programs to allocate up to 3GB of memory, whereas other wise they are limited to only 2GB. This does not change how much memory windows can see.
its not a bios issue, most if not all modern bios' should be able to read 4GB, some intel only like 3GB iirc but its still more than 2GB. As a general rule 32bit xp can see 4GB but only utilises upto 3GB with programs due to it allocating memory for system components such as graphics, sound, pci bus etc - this is generally 2GB with 4GB installed when the switch is not added.
Windows has a really weird configuration when more than 2GB is installed. Instead of increasing the amount of useable ram for programs (and as such visible in task manager etc) it shunts the extra onto the system ram. To claim back the extra gig when there is more than 2GB you need to apply the /3GB (this does not always work with all programs)
link on the topic
Also within windows the amount of ram visible can vary depending on what you use. System properties/Task manager only shows the usable ram for the programs (ie ram which is accessible within windows) so without the 3GB switch it will only show 2GB. Add the 3GB switch and it will show 3GB.
I can confirm this is what happens as I run 4GB ram on 32bit windows xp pro with the 3GB switch.
The above is working with xp
EDIT - and to add the /3GB switch in vista 32bit - linky
Windows has a really weird configuration when more than 2GB is installed. Instead of increasing the amount of useable ram for programs (and as such visible in task manager etc) it shunts the extra onto the system ram. To claim back the extra gig when there is more than 2GB you need to apply the /3GB (this does not always work with all programs)
link on the topic
Also within windows the amount of ram visible can vary depending on what you use. System properties/Task manager only shows the usable ram for the programs (ie ram which is accessible within windows) so without the 3GB switch it will only show 2GB. Add the 3GB switch and it will show 3GB.
I can confirm this is what happens as I run 4GB ram on 32bit windows xp pro with the 3GB switch.
The above is working with xp
EDIT - and to add the /3GB switch in vista 32bit - linky
Explanation of the /3GB Switch
What people really need is the /PAE switch. This lets the processor use a special memory addressing mode which allows you to use all your available memory.
Although you are correct in saying you don't have a physical legacy bios, windows is using a virtual one. This virtual one may not be set up properly.
Mac OSX tiger has 64-bit memory extensions. The kernel itself is 64-bit on 64-bit machines. The only reason it is not said to be fully 64-bit is because some of the library (quartz and what not) are still 32-bit. Thus on tiger you can run a 64-bit thread but only have a 32-bit interface.
Are you using 64-bit linux? Linux handles memory differently from windows. Maybe it just uses the /PAE and /3GB switchs that windows has as options.
No the problem is your lack of understanding on the issue.
Actually linux shunts the memory to 3GB / 1GB just like windows with the /3GB switch. Linux just does this automatically whereas windows does not for compatibility reasons.
Just for your information the upper limit for memory is about 3.5GB without PAE. There is only about 512MB allocated for other devices in a PC.
What people really need is the /PAE switch. This lets the processor use a special memory addressing mode which allows you to use all your available memory.
Windows needs a bios to boot. EFI is a new version of the BIOS. Apple added bios emulation to the EFI layer to allow you to boot to windows.
Although you are correct in saying you don't have a physical legacy bios, windows is using a virtual one. This virtual one may not be set up properly.
Mac OSX tiger has 64-bit memory extensions. The kernel itself is 64-bit on 64-bit machines. The only reason it is not said to be fully 64-bit is because some of the library (quartz and what not) are still 32-bit. Thus on tiger you can run a 64-bit thread but only have a 32-bit interface.
Are you using 64-bit linux? Linux handles memory differently from windows. Maybe it just uses the /PAE and /3GB switchs that windows has as options.
It is most certainly a problem with Windows.
No the problem is your lack of understanding on the issue.
Actually linux shunts the memory to 3GB / 1GB just like windows with the /3GB switch. Linux just does this automatically whereas windows does not for compatibility reasons.
Just for your information the upper limit for memory is about 3.5GB without PAE. There is only about 512MB allocated for other devices in a PC.
pae is installed automatically with the latest drivers, it is not added to my boot.ini in xp
Are you sure about the 512MB used bit because that isn't the case with mine. The absolute maximum my memory could be after any deductions is 3.25GB (graphics card taking some extra and so only showing 3GB).
Are you sure about the 512MB used bit because that isn't the case with mine. The absolute maximum my memory could be after any deductions is 3.25GB (graphics card taking some extra and so only showing 3GB).
to see more than 2GB of RAM in Windows, you will need a 64bit version of Vista or XP installed. 32bit XP (regular XP) and 32bit Vista will only show 2GB of ram.
What TBi is saying is correct, and no amount of switches if configuration will change this. Its to do with the way Apple's EFI implements the legacy BIOS. 64bit OSes will see all your RAM, 32bit Windows will only ever see 2GB.
Trust me on this, I have installed various Windows in BC loads of times, and the only way to get more than 2GB show up is to use a 64bit windows.
What TBi is saying is correct, and no amount of switches if configuration will change this. Its to do with the way Apple's EFI implements the legacy BIOS. 64bit OSes will see all your RAM, 32bit Windows will only ever see 2GB.
Trust me on this, I have installed various Windows in BC loads of times, and the only way to get more than 2GB show up is to use a 64bit windows.
I can also confirm that 32bit Vista won't see any more than 2GB. While there are some downsides of using 64bit Vista (lack of BT drivers for example), there are other benefits, including the ability to use more than 2GB. After a "less than successful" upgrade from XP to Vista Ultimate 32bit, I did a clean install of Vista Ultimate 64bit, and it works great. If you are interested, you might want to read the following link:
http://www.wintellect.com/cs/blogs/...ta-x64-on-a-mac-pro-totally-awesome-dude.aspx
http://www.wintellect.com/cs/blogs/...ta-x64-on-a-mac-pro-totally-awesome-dude.aspx
GG, TBi. Nice flamebait.
Flame bait? Ya i thought your posts were that alright.
MacPro Vista 2GB limit solved !!!!
Folks, finally relief comes with Vista SP1. Some of us poor sods who bought the MacPro intending to use it as a Windows machine as well could not get Vista to see more than 2GB of RAM , however much RAM was actually present. I installed SP1 in the fervent hope that this would be fixed and IT HAS BEEN FIXED ! Now my system reports 4GB of memory and all is well with the world again!
Folks, finally relief comes with Vista SP1. Some of us poor sods who bought the MacPro intending to use it as a Windows machine as well could not get Vista to see more than 2GB of RAM , however much RAM was actually present. I installed SP1 in the fervent hope that this would be fixed and IT HAS BEEN FIXED ! Now my system reports 4GB of memory and all is well with the world again!
Clarification
I forgot to clarify that I am using Vista 32 bit, not 64 bit and it now sees 4 GB of RAM. It is interesting to speculate whether it was an Apple problem that MS worked around or it was an MS problem all along. Since Dell and others have been delivering Vista 32 machines with 4GB of RAM, there is not enough evidence to suggest that it was an MS problem. On the other hand, with SP1 update the problem disappeared......Any ideas ??
I forgot to clarify that I am using Vista 32 bit, not 64 bit and it now sees 4 GB of RAM. It is interesting to speculate whether it was an Apple problem that MS worked around or it was an MS problem all along. Since Dell and others have been delivering Vista 32 machines with 4GB of RAM, there is not enough evidence to suggest that it was an MS problem. On the other hand, with SP1 update the problem disappeared......Any ideas ??
mac pro vista and ram
Just read your post and would like to make sure I understand what you are saying.
Here my problem. I am running Vista Ultimate 32 bit. I have a Mac Pro but perfer to use Vista. I have 8gb of ram however when I am in Vista which is most of the time, it only sees 2gb as you say.
I do video editing and use Avid and its wants to see way more than 2gb of ram so it will not run.
So you say if I do a clean/full install of Vista 64 bit then Vista will see more ram? and the EFI from the Mac Pro will not prevent Vista from seeing more than 2 gb of ram?
Not sure if VMware is a solution because I am not sure how much ram it will allocate to Vista and it does not have firewire support...but it might be a temp solution.
So then if I get a Vista 64 bit it will solve this ram problem?
Jim
Just read your post and would like to make sure I understand what you are saying.
Here my problem. I am running Vista Ultimate 32 bit. I have a Mac Pro but perfer to use Vista. I have 8gb of ram however when I am in Vista which is most of the time, it only sees 2gb as you say.
I do video editing and use Avid and its wants to see way more than 2gb of ram so it will not run.
So you say if I do a clean/full install of Vista 64 bit then Vista will see more ram? and the EFI from the Mac Pro will not prevent Vista from seeing more than 2 gb of ram?
Not sure if VMware is a solution because I am not sure how much ram it will allocate to Vista and it does not have firewire support...but it might be a temp solution.
So then if I get a Vista 64 bit it will solve this ram problem?
Jim
Ya I thought too. After the SP1 update, my performance setting in control panel said I now had all of my 8gb. However when I looked in Task manager I saw that Vista is only able to use 2gb.
