4gb ram issue.

ezzetabi · 2009-01-09 22:29:29

I updated my laptop, it had 1gb of ram and it worked fine.
I removed the 1gb ram module and put 2 3gb modules.

My bios POST messages correctly show 4096mb of ram... but:

$ free -m
             total       used       free     shared    buffers     cached
Mem:          3017        422       2594          0         47        155
-/+ buffers/cache:        219       2797
Swap:         1027          0       1027

I have no ideas, I am pretty sure the ram isn't used but the video card since it did not used ram when I had only 1gb.

What can I do?
thanks

R00KIE · 2009-01-09 23:23:55

You are using a 32bit version of Arch, to get all the ram you have two choices, either recompile the kernel and activate the support for 64GB or you move to Arch64.

ezzetabi · 2009-01-10 16:39:12

I do have a 64 bit, my uname -a is
Linux nakoruru 2.6.27-ARCH #1 SMP PREEMPT Sun Dec 21 09:13:30 UTC 2008 x86_64 Intel(R) Core(TM)2 CPU T7200 @ 2.00GHz GenuineIntel GNU/Linux

Allan · 2009-01-10 16:57:02

I run memtest on it. Perhaps one of your memory modules has trouble.

Alexdsan · 2009-01-10 16:59:33

I have problem too.

$ free -m
             total       used       free     shared    buffers     cached
Mem:          3955       1986       1968          0         79       1228
-/+ buffers/cache:        678       3276
Swap:          956          0        956

$ uname -a
Linux archlinux 2.6.27-ARCH #1 SMP PREEMPT Sun Dec 21 09:13:30 UTC 2008 x86_64 Intel(R) Core(TM)2 Duo CPU E4500 @ 2.20GHz GenuineIntel GNU/Linux

Sander Hoksbergen · 2009-01-10 17:06:43

Eh, please clarify, because I don't see any real problem with that.

ezzetabi · 2009-01-10 17:17:08

I am afraid I have to give up, it seems it is a mainboard limit. Inside my bios settings I can read: memory 4096, available to OS 3017... I am not sure why, but I guess it can not be solved.

pointone · 2009-01-10 18:33:27

Check your BIOS for an option to enable EM64T or something along those lines.

skottish · 2009-01-10 18:34:21

Alexdsan wrote:

I have problem too.

$ free -m
             total       used       free     shared    buffers     cached
Mem:          3955       1986       1968          0         79       1228
-/+ buffers/cache:        678       3276
Swap:          956          0        956

$ uname -a
Linux archlinux 2.6.27-ARCH #1 SMP PREEMPT Sun Dec 21 09:13:30 UTC 2008 x86_64 Intel(R) Core(TM)2 Duo CPU E4500 @ 2.20GHz GenuineIntel GNU/Linux

You're problem is different than the opening post. As root, try this:

cat /var/log/kernel.log | grep -A3 "Your BIOS"

If you see something like the following, you need to update your BIOS:

Jan 10 07:52:18 iasE Your BIOS doesn't leave a aperture memory hole
Jan 10 07:52:18 iasE Please enable the IOMMU option in the BIOS setup
Jan 10 07:52:18 iasE This costs you 64 MB of RAM
Jan 10 07:52:18 iasE Mapping aperture over 65536 KB of RAM @ 20000000

Alexdsan · 2009-01-10 20:04:16

cat /var/log/kernel.log | grep -A3 "Your BIOS"

Did not return information.

you need to update your BIOS:

Updated the bios and not solved the problem.

 cat /proc/meminfo 
MemTotal:      4050056 kB
MemFree:       3435352 kB
Buffers:         17132 kB
Cached:         172832 kB
SwapCached:          0 kB
Active:         408852 kB
Inactive:       143256 kB
SwapTotal:      979924 kB
SwapFree:       979924 kB
Dirty:              32 kB
Writeback:           0 kB
AnonPages:      362220 kB
Mapped:          62688 kB
Slab:            25760 kB
SReclaimable:    18012 kB
SUnreclaim:       7748 kB
PageTables:       9896 kB
NFS_Unstable:        0 kB
Bounce:              0 kB
WritebackTmp:        0 kB
CommitLimit:   3004952 kB
Committed_AS:   713276 kB
VmallocTotal: 34359738367 kB
VmallocUsed:    110152 kB
VmallocChunk: 34359627259 kB
DirectMap4k:     17280 kB
DirectMap2M:   4175872 kB

PS: Enabled 64 mode in BIOS
PS2: I have vga offboard no TC

I'm confused on what this source correctly returning the total size of memory.

???

Last edited by Alexdsan (2009-01-10 23:35:50)

skottish · 2009-01-10 22:53:21

Alexdsan wrote:

... snip ...

I don't won't to hijack this thread much more unless ezzetabi is done with it. With that being said, if it's not the aperture hole, the only other thing I can think of is that you have shared RAM with a video card, whether you use it or not.

Just a side note, if you can avoid posting large(ish) screenshots, it will be appreciated. Please, just follow the guidelines here:

http://bbs.archlinux.org/viewtopic.php?id=61754

R00KIE · 2009-01-10 23:09:56

Check the manual of your board and see if you can find the limit. I guess some boards played that stunt (bad board design, detects the 4GB+ but can't address them because there aren't enough pcb traces to do so) What board is it? (manufacturer and model). A good place to look for help/info may be the manufacturer's forum, probably someone else has/had the same problem and may know of a fix.

Alexdsan · 2009-01-10 23:41:05

Just a side note, if you can avoid posting large(ish) screenshots, it will be appreciated. Please, just follow the guidelines here:
http://bbs.archlinux.org/viewtopic.php?id=61754

Sorry, already fixed.

Check the manual of your board and see if you can find the limit. I guess some boards played that stunt (bad board design, detects the 4GB+ but can't address them because there aren't enough pcb traces to do so) What board is it? (manufacturer and model). A good place to look for help/info may be the manufacturer's forum, probably someone else has/had the same problem and may know of a fix.

My board support up to 8GB.

I will test other 64-bit systems to see if the same problem happens.

R00KIE · 2009-01-11 00:47:27

Well ... if you want to hear something similar .... my notebook: BIOS says that the system has 3072MB of ram (inside the bios, information screen), then during post it says 4096MB (sometimes I can see it counting up to 5***MB can't see the number, it always decides to finally show 4096MB), my Arch64 install complains about the IOMMU and free -m reports 3950 as expected in this case but in dmesg I get something like this:

Memory: 4043016k/5242880k available (2532k kernel code, 149452k reserved, 1041k data, 336k init)

I'm sure this laptop only has 4GB of ram, I have just opened it and checked the stickers on the ram its 2GB + 2GB.

I have recompiled the kernel on my Arch32 install and free -m reports 4050 .... yay and on dmesg I see

Memory: 4145732k/5242880k available (2159k kernel code, 46808k reserved, 831k data, 288k init, 3276384k highmem)

Isn't this just great HAHA.

Last edited by R00KIE (2009-01-11 00:53:55)

ezzetabi · 2009-01-11 18:21:06

I do not find anything like EM64T, maybe should I update the bios?

rocktorrentz · 2009-01-24 20:11:23

How about something along the lines of memory remapping? That's what I had to change to get over 3gb working on my asus mobo.

Ranguvar · 2009-01-25 01:01:07

I don't know what rocktorrentz is referring to, but here are the things I know cause this problem (@pointone, if EM64T was disabled, they could not be running a 64-bit OS in the first place.... and @ezzetabi, many BIOSes don't have such an option, it's just always on):

1.) 32-bit non-PAE OS (obviously not the case)
2.) RAM problem (Run Memtest+, it's on SystemRescueCd and on the Arch CD, this also helps debugging, see whether Memtest+ can see all of the RAM)
3.) RAM slot problem (same test as above, try mviing around the modules)
4.) Motherboard is incapable of handling above a certain amount of memory, or (more likely) can only accept a certain configuration of modules. My old mobo had 3 slots, and could only handle 1 double-sided RAM stick (most are), and in that case, would only take 1 more single-sided. Read your mobo manual or such.
5.) Old BIOS - update.
6.) Otherwise mis-configured BIOS, try resetting it.

Also, try using other modules or putting yours in a friend's machine.
5.)

Arch Linux

#1 2009-01-09 22:29:29

4gb ram issue.

#2 2009-01-09 23:23:55

Re: 4gb ram issue.

#3 2009-01-10 16:39:12

Re: 4gb ram issue.

#4 2009-01-10 16:57:02

Re: 4gb ram issue.

#5 2009-01-10 16:59:33

Re: 4gb ram issue.

#6 2009-01-10 17:06:43

Re: 4gb ram issue.

#7 2009-01-10 17:17:08

Re: 4gb ram issue.

#8 2009-01-10 18:33:27

Re: 4gb ram issue.

#9 2009-01-10 18:34:21

Re: 4gb ram issue.

#10 2009-01-10 20:04:16

Re: 4gb ram issue.

#11 2009-01-10 22:53:21

Re: 4gb ram issue.

#12 2009-01-10 23:09:56

Re: 4gb ram issue.

#13 2009-01-10 23:41:05

Re: 4gb ram issue.

#14 2009-01-11 00:47:27

Re: 4gb ram issue.

#15 2009-01-11 18:21:06

Re: 4gb ram issue.

#16 2009-01-24 20:11:23

Re: 4gb ram issue.

#17 2009-01-25 01:01:07

Re: 4gb ram issue.

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