Question: 3GB of ram only seen as 2GB...

[Mark099]

Hi Gang,

I got some new hardware today....

EVGA X58 SLI Motherboard (latest BIOS)
Core i7 920 CPU
Corsair 3x1GB Tri-Channel PC3-1333 DDR3

Initially, I installed Win XP Pro 32-bit, but Windows only recognized 2GB of ram. CPU-Z listed 3GB. Then I installed Vista Ultimate 32-bit. Same problem. Finally went on to Ultimate 64-bit and all 3GB is recognized.

The problem is Vista uses pretty much all the ram, and I wanted to wait a while before buying more ram (i.e. for some price drops).

I'd prefer to use Win XP in the meantime if I can figure out a solution to the problem. Any ideas?

[tiro_uspsss]

enabled mem re-mapping in BIOS?

[Mark099]

enabled mem re-mapping in BIOS?

The option is not there in the BIOS to do anything with, however, I did find the answer.

Why does my X58 motherboard only show 2GB of memory in XP 32bit when I have more than 2GB installed?

Answer / Solution

This is a normal occurance due to the amount and complexity of the onboard peripherals on the X58 motherboard.

Due to this the motherboard will allocate some memory to itself for these peripherals.

It is reccomended to use a 64 bit operating system if you would like to utilize the full amount of memory.

[SoulsCollective]

The slightly more technical answer is that a 32-bit OS can only address 2^32 bytes - or precisely 4GB. This is a hard limitation, no workarounds, as to speed up operation your OS, rather than having lookup tables or whatnot, directly maps every resource within that address scheme, not only RAM. So, out of that 4GB comes first system devices and things like the PCI bus, then HDD cache and the like, then video memory (which is where the lions share of the available address space is eaten up, with modern cards having up to 2GB of video memory), and then finally anything left over is available to address your RAM.

If you'd done a little searching before you posted your new thread you'd have seen that this is a very common question with literally dozens of threads on the same topic ;)

[Mark099]

I am familar with the ram limitations of 32-bit Windows. The main issue is that each manufacture and (even) motherboard deals with the issue in a different manner. For example, the Asus P5B board I have with 4GB of ram installed is different than an Asus P5K-E WiFi or a Gigabyte P35-DS3L.

P5B: Memory Remapping Enabled --> 2GB of ram in system properties: Disabled: 3GB of ram in system properties
P5K-E: Enabled --> 3.25GB of ram in system properties: Disabled: 3GB of ram in system properties
P35-DS3L: No option to enable/disable --> 3.62GB of ram in system properties

I am a little pissed because in the 100+ reviews on NewEgg and the hardware reviews I have read I could not find any mention of this issue. If I had seen it, I would have likely not bought the EVGA board, or at least I would have gone for a 6GB tri-channel kit at $50 cheaper than buying two (instead of one) of the 3GB Corsair kits I bought.

[zanzabar]

if u make a memtest disk dose the other ram show up, it seams like a dead stick to me, especially if u only have a 512MB card

[Mark099]

if u make a memtest disk dose the other ram show up, it seams like a dead stick to me, especially if u only have a 512MB card

That was one of the first things I thought of but memtest ran error free. Anyway, 3GB of ram shows up in the BIOS and with CPU-Z.

[xanvincent]

To answer your question, you need a 64-bit operating system.

[Mark099]

To answer your question, you need a 64-bit operating system.

The question has already been answered, thanks for reading. :up: