Edgy 7.04 does not use all RAM: it sees only 2GB of the 4GB available
Bug #153830 reported by
Ronald Koster
| Affects | Status | Importance | Assigned to | Milestone | |
|---|---|---|---|---|---|
| Ubuntu |
Invalid
|
Undecided
|
Unassigned | ||
Bug Description
My computer has 4GB of RAM. When I install Edgy 7.04 32bit version all works fine except it detects only 2GB of RAM. uname -a output:
Linux mycomputername 2.6.20-16-generic #2 SMP Wed May 23 01:46:23 UTC 2007 i686 GNU/Linux
When testing RAM directly from the Ubuntu install CD it does detect all 4GB without errors.
System info:
Motherboard: Asus P5B-E Plus
CPU: Intel Core2Duo E6600 2.4GHz S775 BOX
Obviously I want it to use all 4GB instead of only 2GB.
Revision history for this message
| Chris Halse Rogers (raof) wrote | #1 |
To post a comment you must log in.
This is likely due to memory mapping of I/O regions - various devices such as your graphics card, AGP/PCI-E busses, etc get mapped into the address space of the processor so that reads/writes to those addresses go to the appropriate device rather than to RAM. Sadly, the total address space for a 32bit processor is 4GB, and the memory-mapped devices generally get mapped to addresses in the 2GB-3GB range. Sometimes (in your case, for example) this confuses things sufficiently for the RAM above the memory mapped devices to be not detected, but even without that problem you won't get your full 4GB of ram available, and there's nothing we can do about it.
Your options include:
* using the -server kernel - this has the PAE extension enabled, which increases the address space out to 64GB. This should fix your problem, although it's a bit slower (which is why it's not enabled by default).
* using the 64bit version of Ubuntu 7.04. x86-64 has a huge address space, which is pretty much the whole point of x86-64.