Suddenly my RAM lost half its capacity (from 4GB to 2GB)

A rather odd issue happened to my system. I just noticed that it lost half its memory!

I have two sticks of 2GB running in dual channel. They have worked fine and I've always had a total of 4GB memory.

Lately the system has been running slow. I was convinced it was just in need of a reformat.

Out of luck, I happened to notice the RAM count in the System panel. To my surprise it said 2.0 GB !

So low and behold, after testing with a couple of other sticks my roomates had lying around, my two sticks have reduced themselves to 1 GB each.

The weird thing is that my system has had good stability and the RAM is still running in dual channel mode.

So anyways, my question: is this RAM fuxored? Or is there a way I can "wake up" each of the sticks to remember their full capacity?

The RAM is Kingston HyperX DDR2 8500.

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Need to include the details - make and model of motherboard, model of the RAM - more than one Kingston DDR2

What OS are you running?

What does the BIOS/POST say about your RAM? Does it show/count 2GBs or 4GBs?

------------------------------ Gigabyte MA785GM-US2H, AMD Phenom II x2 550 BE (4 cores@3.6GHz), G.Skill 2x2GB DDR2 1066 (820@CL4), Scythe Katana3, Hec 585W, Samsung 2232BW+, WD Caviar Black 1TB SATA, Sea 500GB USB, 12 IDE HDs w/Masscool IDE-SATA Convertors, Ugly Old Case, Win XP 32bit
Reply to mongox

To clarify the RAM, it is a Kingston 2GB PC2-850 1066MHz DDR2 Kit. The exact model is KHX8500D2K2/2GN

BIOS verifies that there is only 2 GB running. Even though both sticks of 2GB are inserted, which should equal 4 GB (like it used to).

Motherboard is the ASUS P5E. OS is Windows XP 32Bit. I have tested with another set of 2x 2GB DDR 8500 sticks and the BIOS verified 4 GB as normal. So its not the motherboard or anything else, its got to be these two sticks.

Reply to redsmurf

I'd try booting it with only one stick installed. Most MBs will allow this and disable dual-channel.

Test each stick first by simply booting and seeing what is displayed in BIOS for system memory. If one won't boot and the other will, you have your problem solved.

If they both boot as singles, run memtest86 on each stick.

------------------------------ Gigabyte MA785GM-US2H, AMD Phenom II x2 550 BE (4 cores@3.6GHz), G.Skill 2x2GB DDR2 1066 (820@CL4), Scythe Katana3, Hec 585W, Samsung 2232BW+, WD Caviar Black 1TB SATA, Sea 500GB USB, 12 IDE HDs w/Masscool IDE-SATA Convertors, Ugly Old Case, Win XP 32bit
Reply to mongox

32 bit system only support up to 3GB of RAM
64 bit system support 4GB+ of RAM

hope that helps

Reply to play

Thanks play! Quite true and something many forget is that Windows needs 64-bit version to see more than 4GBs of RAM - it generally shows anywhere from 3GBs to 3.5GBs, depending on how much RAM the video uses.

That's why I was most interested in how much RAM the BIOS showed - since it's not affected by Windows. Even if the user had 8GBs of RAM and Win95, it would show 8GBs in the BIOS and POST if the hardware is working right.

------------------------------ Gigabyte MA785GM-US2H, AMD Phenom II x2 550 BE (4 cores@3.6GHz), G.Skill 2x2GB DDR2 1066 (820@CL4), Scythe Katana3, Hec 585W, Samsung 2232BW+, WD Caviar Black 1TB SATA, Sea 500GB USB, 12 IDE HDs w/Masscool IDE-SATA Convertors, Ugly Old Case, Win XP 32bit
Reply to mongox

When each stick is tested individually, they indeed only show up as 1.0 GB. They should both be 2 GB, it says right on the sticker. Any other stick of RAM I have tested posts its normal size (2 GB typically).

Whats weird is how both sticks simeoltaneously have reduced themselves to 1 GB. Very odd.

I'll run memtest86 on them as suggested.

Reply to redsmurf

did you buy a 2gb kit or a 4gb kit.
whats the link to the item you bought?

some kits are advertised as 2gb but its 2 1gb chips.

EDIT: after 32.5seconds of googling

i see the problem kingston is confusing you

KHX6400D2LLK2/2GN 2GB 800MHz DDR2 Non-ECC
Low-Latency CL4 NVIDIA SLI-READY (Kit of 2) 4-4-4-12 2.0V (Datasheet) BUY

seems to indicate its 2 2gb chips but if you read the datasheet...

http://www.valueram.com/datasheets [...] K2_2GN.pdf

Kingston's KHX6400D2LLK2/2GN is a kit of two low-latency 128M x 64-bit 1GB (1024MB)
DDR2-800 CL4 SDRAM (Synchronous DRAM) memory modules that are NVIDIA® SLI™ -Ready.
Both modules are based on sixteen 64M x 8-bit DDR2 FBGA components. Total kit capacity is 2GB
(2048MB).

summary.. you bought 2 gb of memory not 4gb.

Message edited by rand_79 on 10-17-2009 at 08:32:53 PM

Reply to rand_79

Well I'll be dammed!

Reply to redsmurf

Argh, I should have caught that but didn't look up the specs when you posted the part#!!! I'm an idiot!

2 secs on Newegg - lol
Kingston HyperX NVIDIA SLI-Ready 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500) Dual Channel Kit Desktop Memory - Retail
http://www.newegg.com/Product/Prod [...] D2K2%2f2GN

------------------------------ Gigabyte MA785GM-US2H, AMD Phenom II x2 550 BE (4 cores@3.6GHz), G.Skill 2x2GB DDR2 1066 (820@CL4), Scythe Katana3, Hec 585W, Samsung 2232BW+, WD Caviar Black 1TB SATA, Sea 500GB USB, 12 IDE HDs w/Masscool IDE-SATA Convertors, Ugly Old Case, Win XP 32bit
Reply to mongox

redsmurf wrote :

A rather odd issue happened to my system. I just noticed that it lost half its memory!

I have two sticks of 2GB running in dual channel. They have worked fine and I've always had a total of 4GB memory.

Lately the system has been running slow. I was convinced it was just in need of a reformat.

Out of luck, I happened to notice the RAM count in the System panel. To my surprise it said 2.0 GB !

So low and behold, after testing with a couple of other sticks my roomates had lying around, my two sticks have reduced themselves to 1 GB each.

The weird thing is that my system has had good stability and the RAM is still running in dual channel mode.

So anyways, my question: is this RAM fuxored? Or is there a way I can "wake up" each of the sticks to remember their full capacity?

The RAM is Kingston HyperX DDR2 8500.

So please explain what happened here? You said it was 4GBs - never mentioned buying new RAM? Was it never really 4 and you didn't notice?

------------------------------ Gigabyte MA785GM-US2H, AMD Phenom II x2 550 BE (4 cores@3.6GHz), G.Skill 2x2GB DDR2 1066 (820@CL4), Scythe Katana3, Hec 585W, Samsung 2232BW+, WD Caviar Black 1TB SATA, Sea 500GB USB, 12 IDE HDs w/Masscool IDE-SATA Convertors, Ugly Old Case, Win XP 32bit
Reply to mongox

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