[need help] Why my system reporting 3G RAM while 4G installed

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fuyun1965

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Hi, I am new to install Freenas 8.0.1 beta 4 on an old 775 P4 system. Hardware detail is as followed:
MB Asus P5P800VM (Intel 865 chipset. BIOS version 1004)
CPU P4-630 (3.0Ghz w/HT)
Ram 1G x 4
HDD WD20EARS 2T x 3
usb drive Kingston 4G

The Freenas system status is showing 3048M RAM, while I just reserved 4M from the 4G to VGA usage. I am planning to use ZFS, forming a pool in Raidz. So Memory is very important for me. Please help.

Thanks!
Fuyun
 

survive

Behold the Wumpus
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Hi fuyun1965,

My first guess is that you are running the 32bit version. If you can, try the 64bit (AMD64) build.

-Will
 

survive

Behold the Wumpus
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Hi guys,

I don't think it's because Asus cut corners as much as that's just the way a 32 bit system lays out the system's memory. Take a look at this post:

http://www.dansdata.com/askdan00015.htm

It seems to explain what's going on pretty well.

-Will
 

kashiwagi

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The pentium 4 is a 32 bit CPU. And only being able to address around 3-3.3GB of RAM in a 32 bit architecture is normal. If you really need more memory, you need to upgrade to an AMD64 platform.
 
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Hi guys,

I don't think it's because Asus cut corners as much as that's just the way a 32 bit system lays out the system's memory. Take a look at this post:

http://www.dansdata.com/askdan00015.htm


It seems to explain what's going on pretty well.

-Will

No dan's wrong on many points, the 3 GB barrier is 32 bit windows related, it's not a 32 bit operating system limitation. for reference, I have 2 linux boxes with 8 GB of ram each, one is 32 bit, one is 64 bit. the problem you have is the motherboard can only address 32 bits and your board (as does my a8n-sli) reserves part for other devices (video, disk, etc), you should read up on PAE if you want to learn more about addressing past the 32 bit mark with a 32 bit processor, it's was introduces with the Pentium pro in 1995.

http://en.wikipedia.org/wiki/Physical_Address_Extension



The pentium 4 is a 32 bit CPU. And only being able to address around 3-3.3GB of RAM in a 32 bit architecture is normal. If you really need more memory, you need to upgrade to an AMD64 platform.

see above, you do not need a 64 bit processor to use more than 4 GB of ram, you need hardware that supports it and an os that isn't windows.
 

survive

Behold the Wumpus
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Hi guys,

According to Intel the P4-630 chip does indeed support 64 bit.

Take a look here: http://ark.intel.com/products/27478

So I would encourage you to try the 64bit build of FreeNAS and see if it lets you use all your ram.

-Will
 
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i just ran a VM with 3.5 G of ram with 32 bit FreeNAS, it detected 3377MB of memory, i created a 64 bit VM with 10 GB of ram and installed 32 but FreeNAS, it also detected 3377 MB of ram. your issue is hardware related. although i did learn that PAE is not enabled for the 32 bit version's Kernel.

i would also recommend you install the 64 bit version, but i doubt you'll see any more memory.
 

kashiwagi

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No dan's wrong on many points, the 3 GB barrier is 32 bit windows related, it's not a 32 bit operating system limitation. for reference, I have 2 linux boxes with 8 GB of ram each, one is 32 bit, one is 64 bit. the problem you have is the motherboard can only address 32 bits and your board (as does my a8n-sli) reserves part for other devices (video, disk, etc), you should read up on PAE if you want to learn more about addressing past the 32 bit mark with a 32 bit processor, it's was introduces with the Pentium pro in 1995.

While you do have a valid point with PAE, I think you simplify it a little bit too much, and make it sound like it will always work with anything newer than Pentium Pro and non-windows. I am sure that you already know this, so it is not directed towards you, but more as a FYI towards the people reading the thread. Please have a look at the "3 GB barrier" article on wikipedia:
http://en.wikipedia.org/wiki/3_GB_barrier
 

mchiao

Cadet
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May 31, 2011
Messages
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I had similar problem with my MSI Athlon board. I had 4 GB installed but only 3GB reported by BIO. I went into the bios and played with the memory mapping, I was able to have the bios reporting all 4GB. Once your bios can report all the memory, it shouldn't be an issue for FreeNAS to see those. I dont believe the problem you have has to do with PAE.

Hope this helps.
 
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