3 GIG RAM detected instead of 4???

**phucahwa** · August 18, 2007, 11:18 AM

Weird....

I just put together a computer system with the Intel Core 2 Duo E6850 3.0 Ghz using the motherboard ASUS P5N32-E SLI Plus. Everything working fine xcept for my 4 sticks (1 gig each) of G.Skill memory which only detected as 3 gig when running 32bit WindowXP home. Did i do some thing wrong? I didnt touch anything in Bios setting and have tried re-sitting the sticks.

Also, i got 2 VGA EVHA 512 MB 8600GTS video card set up (SLI). However, when i run Dxdiag, clicked on Display tab, it says i the system only has 512 MB instead of 1 Gig. Did i do something wrong again?

Any ideas on what could have happened? or how i could fix them? Please please please help.

Thanks.

**spartan_phalanx** · August 18, 2007, 11:41 AM

Check this thread out...

http://www.twcenter.net/forums/showthread.php?t=113792

**phucahwa** · August 18, 2007, 01:30 PM

So i guess i wont be able to set it so that the OS will pick up all 4 GIG?? bummer

**Dick** · August 18, 2007, 01:39 PM

It's not that big of a loss, you couldn't have used all of it anyway. Keep the RAM for when you upgrade to vista (when it's more compatible and useable).

**Niccolo Machiavelli** · August 18, 2007, 01:50 PM

Originally Posted by phucahwa

So i guess i wont be able to set it so that the OS will pick up all 4 GIG?? bummer

You'd need a 64 bit OS to fully address them...

**Freddie** · August 18, 2007, 03:42 PM

There is a fix somehwere on MSDN that allows you to use all 4Gb's of ram running XP 32bit, I found whilst I was at work the otherday but now I'm at home I can't find it for love nor money.

Edit
There is another way but it involes messing aorund with the boot.ini file, you need to add /PAE switch to file (make a back up first) and that only works if your hard supports /PAE. If your computer is fiarly new it should work.

**sapi** · August 19, 2007, 01:10 AM

Setting the page file to 0gb should free up the extra memory addresses for 4GB of ram, but it's not something that I'd recommend.

**Simetrical** · August 19, 2007, 01:34 AM

Originally Posted by sapi

Setting the page file to 0gb should free up the extra memory addresses for 4GB of ram, but it's not something that I'd recommend.

Video RAM will still reduce the figure below 4 GB, in this case to somewhere a bit below 3.5 GB.

Setting the page file to (nearly) zero makes perfect sense: you can't use more than 4 GB virtual memory anyway, so this will just move some of that from swap to RAM. That's assuming, anyway, that the kernel maps memory to the page file before RAM, which seems odd. What's your page file size, phucahwa?

Edit: Ah, you have 2×512 MB video RAM, so that's probably your missing gig there. I imagine shrinking the page file wouldn't help, although I don't know.

**sapi** · August 19, 2007, 01:36 AM

Originally Posted by Simetrical

Video RAM will still reduce the figure below 4 GB, in this case to somewhere a bit below 3.5 GB.

Setting the page file to (nearly) zero makes perfect sense: you can't use more than 4 GB virtual memory anyway, so this will just move some of that from swap to RAM. That's assuming, anyway, that the kernel maps memory to the page file before RAM, which seems odd. What's your page file size, phucahwa?

Edit: Ah, you have 2×512 MB video RAM, so that's probably your missing gig there. I imagine shrinking the page file wouldn't help, although I don't know.

Hmm, never knew that video ram took up system memory addresses; I'll have to remember that. Thanks

**Simetrical** · August 19, 2007, 02:05 AM

That's according to, e.g., this article. Certainly I know that part of the old 1 MB of memory was reserved for video memory, so it only makes sense that the same is true now, and it neatly explains phucahwa's having exactly 3 GB of memory (I'm guessing a bit less than that, actually).

**sapi** · August 19, 2007, 02:08 AM

Yeah, that does seem to make sense.

Does that mean, though, that the page file has no effect (otherwise he'd be at 4096-1024-(default page = 1024 iirc)?

**Simetrical** · August 19, 2007, 02:47 AM

Probably. At least, if I were the x86/kernel creators (whoever's decision it is), I would map all physical RAM to the address space before I mapped the first byte of swap. There's no reason to use swap for memory rather than RAM if RAM is available. (Well, if RAM used for disk cache doesn't count as "available", that is.)