Getting the board to recognize 4GB of RAM

[carage]

Hi,

I got a Giagabyte K8NXP-SLI with 4 sticks of 1GB OCZ 3-3-3-8 PC3200 RAM installed.
Unfortunately, the motherboard and Windows only recognizes 3.25GB of RAM.
What happened to the 768MB?
The Gigabyte box did offer a warning saying it is normal to see 4GB recognized as 3.XX GB due to PC design limitations.
How do I get around this? I know some people are running 4GB RAM, how can I make sure the system utilizes all 4GB even if it only shows 3.25GB?
Some people have told me there might be a hidden BIOS operation titled "fix hardware memory hole" that is present on certain models, however I couldn't find it anywhere on mine even after pressing Gigabyte's Ctrl-F1 trick.
I am running BIOS version F9.

 

[papaHesch]

Carage,

I feel your pain on this one. Tried 4GBs and my SCSI raid card vomited every time I tried to remap the over 4 GB memory address. Do video and photo editing on my machine besides games. You defiantly need to contact Gigabyte and ask them if the bios has an option for remapping memory over 4GB for hardware (most important) and potentially a software remapping option. A considerable amount of hardware uses those memory addresses in post. If you are running WinXP32 you will also have some issues sometimes getting windows to recognize the full 4 GBs. Search the forum for help on this one. Without the remapping options it is likely that you will ever see the full 4GB but try this. Pull out every card on your bus besides the video card and reboot twice. How much memory is recognized at this point? If the number is larger then you really need to find out how to remap. You also might just want to return the 2 1GB sticks and just get an additional two 512MB sticks for 3GBs (Dual channel will still run fine). Unless you are doing video or photo editing you really will see no performance gain. In games you will defiantly see no gain. Plus it is cheaper, painless and you can save up for a 7800GTX.


Good Luck and tell me how the bus pull goes,
papa

 

[evilharp]

Originally posted by: carage

Some people have told me there might be a hidden BIOS operation titled "fix hardware memory hole" that is present on certain models, however I couldn't find it anywhere on mine even after pressing Gigabyte's Ctrl-F1 trick.
I am running BIOS version F9.

The 4GB Memory Remap option is usually on the Advanced Options page (CTRL-F1) at the very bottom (at least it is on my GA-K8NS Ultra-939).

What CPU are you running? Some BIOS setups only display options that the CPU will support (remember that the A64 memory controller is on-chip) such as memory dividers, etc... (if it is the FX-55 in your "my rig", it may not have the feature. I didn't see it until I plugged in my X2).

 

[carage]

Originally posted by: evilharp

Originally posted by: carage

Some people have told me there might be a hidden BIOS operation titled "fix hardware memory hole" that is present on certain models, however I couldn't find it anywhere on mine even after pressing Gigabyte's Ctrl-F1 trick.
I am running BIOS version F9.

The 4GB Memory Remap option is usually on the Advanced Options page (CTRL-F1) at the very bottom (at least it is on my GA-K8NS Ultra-939).

What CPU are you running? Some BIOS setups only display options that the CPU will support (remember that the A64 memory controller is on-chip) such as memory dividers, etc... (if it is the FX-55 in your "my rig", it may not have the feature. I didn't see it until I plugged in my X2).

Athlon FX-55 Clawhammer
I got another FX-55 SanDiego lying around, I'll install it today or tomorrow whenever I have the time. Hopefully that will solve the problem.

 

[Peter]

You can't have 4 GBytes of contiguous memory because there are other system devices that must map into 32-bit space. BIOS ROM image, all PCI device resources, and other misc bits and pieces. Particularly because of the graphics card's large RAM size, this easily amounts to a full gigabyte or slightly less - as observed.

All Athlon-64 have the memory remap feature. However, you will obviously need an operating system that supports either 36-bit paged "PAE" addressing, or 64-bit flat mode. That'll be XP Pro or x64 flavors. Normal XP home no can do.

 

[carage]

Alright, I installed my new FX-55 based on the SanDiego core, unfortunately the results are less than encouraging.
Let's start with the good news.
First of all, evilharp is correct, the fix hardware memory hole option did appear right after I installed the new CPU.
Secondly, I was able to boot into Windows on the first attempt with hardware memory hole fix enabled and speed manually set to DDR400.
Now the bad news.
Everything seemed to be fine until I started running Super PI-1M calculation. Something went wrong on the 6th or 7th loop then the system rebooted itself.
After that, the system will either hang on updating DMI pool or it will present a BSOD saying there is something wrong with a347bus.sys
So I started some experimenting. Here is what I have figured out so far.
DDR 400 + hardware memory hole fix enabled = recipe for disaster, sometimes it would hang at the memory test
Just enabling hardware memory hole does not seem to have any effects. Yes, the POST memory test shows 4GB. However, Windows still reports 3.25GB, and I do have /PAE mode enabled. FYI, I am running Windows XP Pro SP2.
Just manually setting the speed to DDR400 is also a recipe of disaster that usually ends in a BSOD or hung DMI Pool Update.
Adding 0.1V to the DRAM voltage seems to have no effects at all.
Now I am running the system with hardware memory hole fix turned on and speed set to default DDR333. I just finished running Super-PI and 3DMark05, so I think it is stable enough.

 

[carage]

I kind of gave up hope on the 4GB issue now.
Although I would like to have all 4 sticks running at DDR400.

 

[funks]

Is the San Diego Core an E core?

On my Epox 9NPA+SLI, I have 4 x 1GB of the OCZ PC3200 Platinum (2 sets of DC RAM).. Processor = X2 4200+

It locked up at the Default SPD Memory values which were

2-3-2-5 (2T) (200 MHZ) (2.6 volts for memory)

I changed the values to

2.5-3-2-8 (2T) (200 MHZ) (2.7 volts for memory)

and the system is completely stable now..

You might want to increase your timings and see if it stabilizes.

With the S/W Memory Hole Remapping Option enabled - WinXP 64 now sees all 4 Gigabytes of RAM, WinXP32 only sees 3GB max.

 

[carage]

It's an SanDiego E4.