Yankee Posted February 3, 2008 Report Share Posted February 3, 2008 Speaking of RAM, all these tips here brought me to this... free total used free shared buffers cached Mem: 515664 509264 6400 0 55380 238160 -/+ buffers/cache: 215724 299940 Swap: 0 0 0 Does that look like the right amount of free RAM for a 512 MB system? This is just after starting up. Quote Link to comment Share on other sites More sharing options...
ianw1974 Posted February 3, 2008 Report Share Posted February 3, 2008 If you're on a 32 bit system, and using a kernel which is limited to 4GB, and you have 3GB or more, then you'll only be able to see 3GB. If you use a kernel capable of 64gb, then you will see 4GB or higher on a 32 bit system. On a 64 bit system, this isn't a problem. Just thought I'd let you know in case you have 3GB or more :) Yankee, yes your memory looks fine to me. Quote Link to comment Share on other sites More sharing options...
scarecrow Posted February 5, 2008 Report Share Posted February 5, 2008 I'm sorry, but this is wrong. You cannot utilize more than 4GB of RAM in any known 32-bit OS (Linux, Windows, BSD, Solaris...) no matter which sort of kernel you are using. The 3 GB is not a strict limit- it depends on the chipset and bios used. It may be less, or more than that- but the 4GB is the upper floor for ANY 32-bit system. Quote Link to comment Share on other sites More sharing options...
Yankee Posted February 5, 2008 Report Share Posted February 5, 2008 All good info... Got a phone call and about lost my thought... I'm getting ready to upgrade to X2 64...This computer has just been so good that I don't wanna let it go... I hear Intel has got it going on, for now... I'm an AMD man, just am...so what ever that 64bit OS can handle is good for me...I remember 8bit... /. Quote Link to comment Share on other sites More sharing options...
ianw1974 Posted February 6, 2008 Report Share Posted February 6, 2008 I'm sorry, but this is wrong. You cannot utilize more than 4GB of RAM in any known 32-bit OS (Linux, Windows, BSD, Solaris...) no matter which sort of kernel you are using.The 3 GB is not a strict limit- it depends on the chipset and bios used. It may be less, or more than that- but the 4GB is the upper floor for ANY 32-bit system. Actually, you are completely wrong. I had a 32 bit distro (gentoo) and I used 64GB in kernel and I could see and use 4GB. When the kernel was set to 4GB, it would only show 3GB. Link to the question I asked on gentoo's forum: http://forums.gentoo.org/viewtopic-t-603941-highlight-.html as evidence you are wrong about a 4GB limit on all 32 bit systems. It will work with 64GB, but uses some paging tricks to do it, which can cause a little resource hit, than using 64 bit. BIOS can cause an issue, as this post shows, but not on all systems. You brand it as all systems cannot do it. Quote Link to comment Share on other sites More sharing options...
jkerr82508 Posted February 6, 2008 Report Share Posted February 6, 2008 From the description of kernel-server-2.6.22.12-1mdv: "......This kernel is compiled for server use, single or multiple i686 processor(s)/core(s) and up to 64GB RAM ....." Jim Quote Link to comment Share on other sites More sharing options...
scarecrow Posted February 6, 2008 Report Share Posted February 6, 2008 (edited) You obviously mean using PAE mode: http://en.wikipedia.org/wiki/Physical_Address_Extension Still you won't be able to use more PHYSICAL RAM with 32-bit applications, even if using special techniques like mmapping under *nix, or AWE under windows. It's simple maths: 2^32 = 4.2 billion, or 4GB. The reason PAE is used on 32-bit server systems is for running special, NON-NATIVE 32-BIT apps. And for the record, an i965 system can use all 4GB of physical RAM with a 4G enabled kernel, unless it's coupled with a tricky videocard. Other chipsets can do equally well, while some others won't even handle 3G. BTW I cannot see something interesting in that Gentoo thread. The only paradox would be compiling a 32-bit kernel for more than 64G of RAM... :P Edited February 6, 2008 by scarecrow Quote Link to comment Share on other sites More sharing options...
ianw1974 Posted February 6, 2008 Report Share Posted February 6, 2008 Just thought I'd add, I'm using Fedora 8 x64 now (have been for the last couple of months or so) ;) My i965 wouldn't use the full 4GB though, until it was changed to 64GB in the kernel. Quote Link to comment Share on other sites More sharing options...
Guest d4v1dv00 Posted March 15, 2008 Report Share Posted March 15, 2008 (edited) From the description of kernel-server-2.6.22.12-1mdv: "......This kernel is compiled for server use, single or multiple i686 processor(s)/core(s) and up to 64GB RAM ....." Jim I having the same issue, I have 4GB of physical RAMs, not sharing with video card (nVidia GeForce 8600M GTX 256MB), using the following (uname -a): Linux localhost 2.6.22.18-server-1mdv #1 SMP Mon Feb 11 16:46:24 EST 2008 i686 Intel® Core2 Duo CPU T7500 @ 2.20GHz GNU/Linux But I only sees 3.5GB although prior this I am able to see 4GB in OpenSUSE 10.3 32bit system. Why? BTW: I am using MandrivaOne 2008.0, earlier installed with kernel-desktop586, then later upgraded to kernel-desktop and now with kernel-server. Edited March 15, 2008 by d4v1dv00 Quote Link to comment Share on other sites More sharing options...
ianw1974 Posted March 15, 2008 Report Share Posted March 15, 2008 As mentioned before, if the kernel is set with a limit to 4GB, then you will only see about 3GB or 3.5GB. Most kernels now in a system have 64GB flag set, so that is why you would probably see the full 4GB on a 32 OpenSUSE system. You can check this by looking at your /boot/config-xxxxxx file and doing: cat /boot/config-xxxxxx | grep -i mem and the flag you need is CONFIG_HIGHMEM64G. If it's set to "y", then that will be why you see the full 4GB. If it's not, then this is why you don't see it. Quote Link to comment Share on other sites More sharing options...
scarecrow Posted March 16, 2008 Report Share Posted March 16, 2008 If your kernel has PAE enabled, it will see all 4 GB of RAM. But I can assure you that performance will be noticeably worse than with a non-PAE kernel. Quote Link to comment Share on other sites More sharing options...
Guest d4v1dv00 Posted March 17, 2008 Report Share Posted March 17, 2008 Thanks alot. I had upgraded my system now running x64 and still i only sees 3.9GB... what a disappointment!. Quote Link to comment Share on other sites More sharing options...
ianw1974 Posted March 17, 2008 Report Share Posted March 17, 2008 And how much do you have? 4GB. Hmm, don't see anything wrong with it. Here is my system: [ian@esprit ~]$ free total used free shared buffers cached Mem: 4056656 1045832 3010824 0 25340 274560 -/+ buffers/cache: 745932 3310724 Swap: 2008084 0 2008084 [ian@esprit ~]$ free -m total used free shared buffers cached Mem: 3961 1021 2940 0 24 268 -/+ buffers/cache: 728 3232 Swap: 1961 0 1961 [ian@esprit ~]$ free -g total used free shared buffers cached Mem: 3 0 2 0 0 0 -/+ buffers/cache: 0 3 Swap: 1 0 1 so rounded down values, so 3.9GB is effectively the same as 4GB. The top one is in KB, so shows the true value. The second one in MB, shows 3.96GB - the same as you. The third shown in GB, shows only 3GB! Or you can check this also: [ian@esprit ~]$ cat /proc/meminfo | grep -i total MemTotal: 4056656 kB SwapTotal: 2008084 kB VmallocTotal: 34359738367 kB HugePages_Total: 0 Nothing to worry about or get disappointed over. However, your performance will be better now. Quote Link to comment Share on other sites More sharing options...
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