{"id":137,"date":"2007-09-27T07:36:00","date_gmt":"2007-09-27T15:36:00","guid":{"rendered":"http:\/\/outflux.net\/blog\/archives\/2007\/09\/27\/stupid-bios-tricks-to-find-your-4g-of-ram\/"},"modified":"2007-10-04T06:38:35","modified_gmt":"2007-10-04T14:38:35","slug":"stupid-bios-tricks-to-find-your-4g-of-ram","status":"publish","type":"post","link":"https:\/\/outflux.net\/blog\/archives\/2007\/09\/27\/stupid-bios-tricks-to-find-your-4g-of-ram\/","title":{"rendered":"stupid BIOS tricks to find your 4G of RAM"},"content":{"rendered":"<p>A few months ago I upgraded my system to 4G of RAM.  Blinded by my shiny new DIMMs, I never actually looked at the output of &#8220;free&#8221;.  All I saw was that the system-monitor applet now showed lots of free memory.  Only recently did I notice that I only had 3G of RAM, instead of my expected 4G.  This is a rather common problem when running a 32bit OS, but I&#8217;ve been running 64bit for a while now.  In fact, since it&#8217;s such a common complaint for 32bit OSes, I didn&#8217;t have any luck Googling for an answer.  I did find references to chipset limitations (motherboards with only a 32bit memory bus), but &#8220;lshw&#8221; seemed to think I was okay.  I had 4 banks each showing:<\/p>\n<blockquote><p>\n        *-bank:0<br \/>\n             description: DIMM DDR Synchronous 333 MHz (3.0 ns)<br \/>\n             &#8230;<br \/>\n             size: 1GB<br \/>\n             width: <strong>64 bits<\/strong><br \/>\n             clock: 333MHz (3.0ns)\n<\/p><\/blockquote>\n<p>On reboot, I also noted that my BIOS said I only had 3G.  I started to get worried, but managed to find a setting on my Northbridge for Memory to enable &#8220;Hardware memory hole&#8221;.  After that, both the BIOS and Linux were happy and seeing the full 4G.  I assume the BIOS just bumps the memory in the 3G region to above 4G, which makes for a silly kernel message:<\/p>\n<blockquote><p>\n[   24.617275] Memory: 3977852k\/<strong>5259264k<\/strong> available (2281k kernel code, <strong>150272k reserved<\/strong>, 1182k data, 300k init)\n<\/p><\/blockquote>\n<p>But I don&#8217;t care.  :)  It works now, and my &#8220;free&#8221; output makes me happy again:<\/p>\n<blockquote>\n<pre>\r\n             total       used       free     shared    buffers     cached\r\nMem:       3986156    3958396      27760          0      68268    2949472\r\n-\/+ buffers\/cache:     940656    3045500\r\nSwap:      3903672      38676    3864996\r\n<\/pre>\n<\/blockquote>\n<p style='text-align:left'>&copy; 2007, <a href=\"https:\/\/outflux.net\/blog\/\">Kees Cook<\/a>. This work is licensed under a <a rel=\"license\" href=\"http:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\">Creative Commons Attribution-ShareAlike 4.0 License<\/a>.<br \/><a rel=\"license\" href=\"http:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\"><img decoding=\"async\" alt=\"CC BY-SA 4.0\" style=\"border-width:0\" src=\"https:\/\/i.creativecommons.org\/l\/by-sa\/4.0\/88x31.png\" \/><\/a> <\/p>\n","protected":false},"excerpt":{"rendered":"<p>A few months ago I upgraded my system to 4G of RAM. Blinded by my shiny new DIMMs, I never actually looked at the output of &#8220;free&#8221;. All I saw was that the system-monitor applet now showed lots of free memory. Only recently did I notice that I only had 3G of RAM, instead of [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[14],"tags":[],"_links":{"self":[{"href":"https:\/\/outflux.net\/blog\/wp-json\/wp\/v2\/posts\/137"}],"collection":[{"href":"https:\/\/outflux.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/outflux.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/outflux.net\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/outflux.net\/blog\/wp-json\/wp\/v2\/comments?post=137"}],"version-history":[{"count":0,"href":"https:\/\/outflux.net\/blog\/wp-json\/wp\/v2\/posts\/137\/revisions"}],"wp:attachment":[{"href":"https:\/\/outflux.net\/blog\/wp-json\/wp\/v2\/media?parent=137"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/outflux.net\/blog\/wp-json\/wp\/v2\/categories?post=137"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/outflux.net\/blog\/wp-json\/wp\/v2\/tags?post=137"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}