searsj

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Hi,
I just upgraded to 1.5gb of Corsair XMS 3-3-3-8. I had 512 before, and I bought a new gig stick. Anyway, on startup the full 1536mb shows up during POST, but when Windows loads only 1.00gb shows. Now, I've tried switching the sticks so that the gig was first and so that it was second. I also tried upgrading to Vista. Neither worked so far. My motherboard is a Foxconn NF4 K8mC. I would definitely enjoy being able to utilize the extra half a gig of RAM. Thanks for any help!
 

erloas

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This is simply a guess, but it could be because your motherboard is trying to match your RAM for Dual Channel mode.
If your 512 stick is single sided and your 1GB stick is dual sided it would mean the 1GB stick is 512 per side, so it may be matching the 512 single side stick with 512 of one side of the 1GB stick and running in dual channel mode and ignoring the second side of the 1GB stick.
I don't know how likely this is, or if its even possible, but I haven't had the opportunity to try either.

I guess one way to check is see what CPU-Z reports and see if it is running in Dual channel mode or not.
I see the motherboard only has 2 RAM slots anyway, otherwise I would suggest trying both chips in different channels.

It might just be a limitation of your motherboard (which says it supports 2GB of memory) with two sticks installed, in which case in order to use the 1GB stick you would have to get another 1GB stick to pair it with.

That is just speculation based on what you've mentioned, if you can find out how CPU-Z is reporting the memory it might make it easier to figure out what is wrong.
 

searsj

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with regard to rodney: haha, it wasn't just the ram thing. i'd been planning the upgrade for a while in order to a) take advantage of the 64 bit cpu b) (buy a legitimate copy of windows:: read upgrade from pre-SP1 bootleg XP and get USB 2.0)

anyway, erlaos -- the motherboard reports that it is running in dual channel mode during POST, but at that point it also claims 1536mb RAM. does this still fit with your hypothesis? i'll run cpu-z when i get home from work. there's no way to disable dual channel in order to test this, is there?
 

rodney_ws

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That's what is so confusing... his board properly recognizes the correct memory amount. I looked up the board the OP mentioned and it shows 4 DIMM sockets although the OP implies he only has 2 memory slots... so I'm not really sure what to say. Vista would definitely appreciate the extra half GB of RAM so this is definitely something worth pursuing.
 

Hatman

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What may be doing it is that he has a 512mb stick and 1 gb stick.

2 sticks.

512 x 2 is obviously 1gb.

It may just be using 512mb of the 1gb stick, if taht is a problem though dont look to me for answers because I got no idea how to go about it lol
 

searsj

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rodney - board definitely only has two dimms -- i think the difference may be between the nf4k8mc-ers and -rs w/ regard to the 2 v 4 thing.

hatman - are you going along with what erlaos said?

i won't be able to see new posts/reply until tomorrow, as our dsl is down right now. but when i get home from work will also test the gig stick and the 512 separately to see what they report in windows. also, im gonna check what ubuntu says... if anyone else has had this problem, lemme know.
 

erloas

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My guess is that when the system first boots up it scans both banks on both memory slots, seeing 3 banks of 512 (one on one stick and 1 on each side of the 1GB stick) then it matchs the 2 banks of 512 and forgets about the last bank of 512 because it doesn't have anything to pair it with.

I haven't seen any place to enable or disable dual memory mode, but thats not to say its not available in some BIOSs.

One thing to check to see if this is even possible is how the chips are laid out on each RAM module. If on the 512 stick all of the chips are on one side and on the 1GB stick both sides seem to be mirrored then it could be possible. If the 512 stick instead has 2 banks of 256 (chips on both sides) then this seems much less likely because I doubt it would be able to match up a 256 bank and a 512 bank.
 

htoonthura

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have you tried with your new 1 gb stick only? Have your system recognized as full 1 gb or 512 mb?
 

searsj

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hey, didn't get a chance to test it yesterday... some things came up and i didn't get home till late. will try just the gig today, let y'all know what happens tomorrow. no internet at home really bites.
 

searsj

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hi, so i tested it yesterday and here goes:

with just the gig stick: 1023mb, 4.5 score on vista's operations per second rating.

with just the 512: 511mb, 2.9 score.

with both: 1023: 4.5

Now, the wierd thing I did notice was that my 128mb 6600GT is showing 376 mb, with 256 of those from shared memory. Could Vista be re-allocating my RAM towards video? or is this hard-drive space that they've reassigned. And, if the former is true, where's the other 256 going?

Finally, with regards to the double sided theory: both sticks (1gb and 512mb) are double sided, so its 2x512 and 2x256. So I don't think that's what is doing it, especially since BIOS picks it up fine.

Any ideas?
 

einheriar

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How many memory slots do you have? If you have 3 or four , have you tried in the two non matching channels? IOW have you been putting them together in the two matching channels alone?

 

searsj

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i don't have onboard video. just a pcie 6600gt. under device manager it specifically is showing up with the extra ram. is that actual ram or virtual memory?
 

searsj

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update: so i'm sick of vista (i know, big surprise). just bought another hd for extra space, will install SP2 back on there. I'll post again if it does anything for my Random *** Memory situation.
 

kpretired

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I am having a similar problem. On my sisters pc, her windows xp is reporting 244 ram, but I know she has 256. What would be causing this? Is there something configured perhaps in bios or windows?