# 1GB RAM - I get only 877MB

## Cr0t

I have a really strange problem. I should have 1024MB RAM but I only get 877MB RAM in Linux. Even sensors tells me that I have one 512MB stick and two 256MB sticks. I played around with lilo's mem option but nothing changed I still have (only) 877MB RAM.sensors | grep SDRAM

Memory type:            SDRAM DIMM SPD

SDRAM Size (MB):        256

Memory type:            SDRAM DIMM SPD

SDRAM Size (MB):        256

Memory type:            SDRAM DIMM SPD

SDRAM Size (MB):        512

I used the memtest86 Program to see if memtest86 finds the 1024MB... memtest86 finds 1024MB RAM even the BIOS tells me that I have 1024MB of RAM but not gentoo... any ideas?   :Crying or Very sad: 

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## delta407

Enable high memory support in your kernel and life should be good.

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## Cr0t

 *delta407 wrote:*   

> Enable high memory support in your kernel and life should be good.

 

(4GB) High Memory Support is on.

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## deathdruid

Some of your RAM is being set aside for kernel mapping of virtual addresses to physical addresses and other overhead associated with CONFIG_HIGHMEM. For example, in a 4 GB machine, only 3 GB is set aside for userspace, while the kernel allocates 1GB for its use.  See here for a nice explanation.

Hope this helps,

Rahul

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## Cr0t

I recompiled the Kernel twice and now it's working   :Razz: 

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