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3gb switch problems

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April 24, 2009 12:10:20 AM

I tried to setup the 3gb switch and now my machine wont even boot to safe mode it keeps hanging up on the Mup.sys file and then just restarts and does the same things again. I tried all the safe mode options. I did save a backup of my boot.ini though, but I am guessing it is a registry thing.

I am posting this to memory because it is something that memory tweakers are going to be messing with...


HELP!


I also do not have my Windows XP disk. Besides, someone told me that trying to repair using and SP! disk with an SP3 update installed will completely fry your windows install and you will have to start all over again anyway.

Can anyone help?

More about : 3gb switch problems

a b } Memory
April 24, 2009 2:52:21 AM

Many prebuilt computers have a copy of Windows installed on the hard drive, and instructions on how to restore (often started by pressing a Function key, such as F2 during boot). I don't know if this applies to you. Obviously it will delete any data you have.

If you modified your Boot.ini file with Notepad, you may be able to find a Torrent copy of BartPE XP or Vista that should enable you to boot off of a CD (into a pseudo Windows environment) and undo the changes you made. It may be possible to yank out your hard drive and add it as a second drive in another computer and change your file back.

I'm guessing you have 4GB of RAM and wanted to use it all in 32-bit. If so, you may not understand the purpose of the switch:
http://dwf.blogs.com/beyond_the_paper/2009/04/enabling-...

I don't know if there is a BIOS setting that you need to enable. Perhaps related to PAE. Probably not.

FYI:
32-bit Windows supports 4GB of memory, of which RAM is just a part. A computer with 32-bit XP and a 512MB video card should "see" about 3.2GB of your 4GB of RAM. In reality, little difference can be noticed by going from 3.2GB to 4GB.

If your CPU is 64-bit compatible (most are, easily googled) consider putting on Windows 7 RC 64-bit when available on 5th May.

Meanwhile, if your XP was installed on a prebuilt system contact the manufacturer. I got laptop Windows install discs from a 5-year old Dell Inspiron and a newer HP when I contacted them.

(I have an Asus A8N-SLI Premium board and upgraded to 4GB. Windows Vista 64-bit registered only 3GB. I changed the appropriate BIOS settings and got my 4GB. I think most motherboards automatically support full RAM use now in 64-bit. This isn't to do with the Switch but these two are related an many get them mixed up.)
April 24, 2009 3:17:10 AM

Its a new Dell Inspiron. I yanked Vista off of it (reformat of drive) and installed XP Sp1, then manually found all the right drivers, and then got everyhting working nicely. It took a few days to get all my Oultlook and Windows Live mail files, and office and other data files all put in there.

Then, though it has 3GB RAM installed, I can only see 2GB and Photoshop is showing me less than 1GB. That sucks. On my desktop I have the 3GB switch in the and have 4GB installed...etc. Photoshop sees over 2GB RAM when I have everyhing else closed...so I have done this before.

I went into the boot.ini and added the 3GB switch, but did not add the other part (I think I put in userva=2800 on my desktop...and had no issues at all)

So then I went to boot windows and I got a corrupt regsitry error and safe mode would not even boot up.

I did a manual regisitry repair from the XP SP1 boot disk.

I was trying not to spend 3 days rebuilding it all over again.

So...I got windows to boot, but it is of course showing all the programs but they arent actually "installed"

So what I do not understand is why you cannot go to system resotre (which wont even pull up right now at all, which I dont understand) and just find the old restore point...which has to be there...and just tell it to restore to that old restore point?

Related resources
April 24, 2009 3:51:56 AM

Awe...screw it. I am just starting over. At least I know how, and I only had the machine a week, so nothing is on there that I cant put back.

By the way, when is someone going to make software taht is bootable and will do this kind of stuff...restore windows from an old resotre point...etc.

Also, I really dont understand why the heck I cant image a drive and just drop it in another computer that has anything otehr than the exact hardware configuration. I imaged my old drive out of my Acer Aspire and tried to simply clone it to the new drive (had the partitions the same configuration and everything) and it just would not work. I dont see the frikking point of backing up the drive then?

Also tried Laplink, and thats frikkin stupid because you have to run it from one bootable windows install to another. What if you computer craps? Then what? So again, what's the point of imaging your drive as a backup if you cant restore to it anyway?

I thought the point was to save your windows install and programs so you can save time doing all that crap all over agan?

So can anyoneexplain to me how the heck you keep yourself backed up so you can really restore to your desired config without wasting a few days each time you put in a new mobo or shipset or whatever?

As you can tell, I am really pissed. I thought I was doing everything I needed to do. Apparently not.

SRM
a b } Memory
April 24, 2009 1:01:27 PM

The /3gb switch has nothing to do with increasing the total amount of available address space. Rather, this is used for adjusting the amount of space provided to Applications versus what is reserved for system usage.

By default, Windows will set aside 2GB of space for the system, and 2GB for Applications. This Neither Increases, Nor Decreases The Total Amount Of Space Available. What the /3GB switch does is change that to 1GB for system needs, and 3GB for applications. So all you did is re-allocate how much is being used for what purpose. There's a problem with that, as you have clearly discovered, where if the system needs more than 1GB of address space to function and can't get it...



Quote:
So can anyoneexplain to me how the heck you keep yourself backed up so you can really restore to your desired config without wasting a few days each time you put in a new mobo or shipset or whatever?



Easy: You make a recovery disc before you wipe your hard drive or make major changes to your system. Doing so after the fact doesn't work.



Anyways - If you want/need to use the full 4GB, or want to add more, then do yourself a favor and skip 32 bit OS's entirely. Contrary to popular belief, 64 bit Windows runs 32 bit Windows app just fine.

April 24, 2009 2:47:45 PM

Those 3 gigabytes - are they shared among all the applications?
April 24, 2009 4:25:37 PM

Scotteq said:
The /3gb switch has nothing to do with increasing the total amount of available address space. Rather, this is used for adjusting the amount of space provided to Applications versus what is reserved for system usage.

By default, Windows will set aside 2GB of space for the system, and 2GB for Applications. This Neither Increases, Nor Decreases The Total Amount Of Space Available. What the /3GB switch does is change that to 1GB for system needs, and 3GB for applications. So all you did is re-allocate how much is being used for what purpose. There's a problem with that, as you have clearly discovered, where if the system needs more than 1GB of address space to function and can't get it...


The 2GB and 3GB are virtual memory limit per process or application (which must support the additional 1GB). The system can still use the same amount of memory, although you will obviously be hitting the page file if one or more apps are using 3GB with only 4GB of RAM.
April 24, 2009 4:48:33 PM

The same thing happens under Vista64 too; I've seen people with 8GB of RAM installed with access to only 4GB while reporting 6.7GB free. Windows will set aside some RAM for the system Kernal by default, to gurentee the system always has enough RAM to work. The /3GB swith simply moves some of that extra RAM to the applications and away from the Kernal, which can cause problems.

The /3GB switch does not increase avaliable RAM past the 4GB mark on a 32bit OS.
April 24, 2009 5:16:17 PM

theAnimal said:
The 2GB and 3GB are virtual memory limit per process or application (which must support the additional 1GB). The system can still use the same amount of memory, although you will obviously be hitting the page file if one or more apps are using 3GB with only 4GB of RAM.

No, if you have changed the layout of the virtual addresss space then only 1 GB is available to the OS.
a b } Memory
April 24, 2009 11:40:11 PM

theAnimal said:
The 2GB and 3GB are virtual memory limit per process or application (which must support the additional 1GB). The system can still use the same amount of memory, although you will obviously be hitting the page file if one or more apps are using 3GB with only 4GB of RAM.



Incorrect. You are confusing "Memory" with "Address Space". The switch is about address space allocation. Memory is along for the ride.

When you use the /3GB switch, the System gets limited to 1GB worth of Address Space. If you have hardware requiring more than that much Address Space, you will encounter serious issues.
April 25, 2009 1:49:31 AM

I have a system with 3gb of RAM and when I right click on mycomputer is says I have...ooops. Now it says I have all 3gb and I do not have the 3gb switch in there. Why did it say 2gb before? I am really baffled now.

Does SP3 update automatically see more ram?

On my desktop I have 4gb in there and what I was told was that the 4th gb of RAM would be used by the vid cards (I have dual 7800GT in there with 512 each)

Anyway, my other machine runs like a champ. I just opened 14 12MP photos at the same time and it still displayed 90% efficiency in Photoshop. It is updated to SP3 too, and I have the 3GB switch installed with the userva=2800 setting in there, which I dont know what that means, but put it in there on the advice of a tech at my local computer store. He doesnt work there anymore...

So I am confused now..

SRM
a b } Memory
April 25, 2009 4:09:30 AM

I use Acronis True Image and create a snapshot of my C-drive and back it up to my 2nd hard drive. I did this 3 times. Once near the beginning, second as thing are mostly installed and third when things are perfect.

I also regularly back up my e-mail and Documents to my 2nd hard drive.

If I hosed the software on my first hard drive, I could boot from the Acronis rescue disc and have Windows running in 15 minutes (depending on size). Compression will vary, for example if you had 4GB of RAM you might have a 4GB Hibernation file and 6GB Pagefile then Acronis notes the numbers but doesn't actually use this space at all for the compressed image but does create it back when Restoring.

I find Acronis True Image indispensible. it's nice feeling to know you can always easily restore to a fully tweaked version of your Operating System.
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