{"id":38093,"date":"2004-08-22T07:00:00","date_gmt":"2004-08-22T07:00:00","guid":{"rendered":"https:\/\/blogs.msdn.microsoft.com\/oldnewthing\/2004\/08\/22\/summary-of-the-recent-spate-of-3gb-articles\/"},"modified":"2004-08-22T07:00:00","modified_gmt":"2004-08-22T07:00:00","slug":"summary-of-the-recent-spate-of-3gb-articles","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/oldnewthing\/20040822-00\/?p=38093","title":{"rendered":"Summary of the recent spate of \/3GB articles"},"content":{"rendered":"<p> A table of contents now that the whole thing is over. I hope. <\/p>\n<ul>\n<li><a href=\"http:\/\/blogs.msdn.com\/oldnewthing\/archive\/2004\/08\/05\/208908.aspx\">The     oft-misunderstood \/3GB switch<\/a>.     It&#8217;s simple to explain what it does, but people often misunderstand. <\/li>\n<li><a href=\"http:\/\/blogs.msdn.com\/oldnewthing\/archive\/2004\/08\/06\/209840.aspx\">Kernel     address space consequences of the \/3GB switch<\/a>.     An adverse consequence of the \/3GB switch. <\/li>\n<li><a href=\"http:\/\/blogs.msdn.com\/oldnewthing\/archive\/2004\/08\/09\/211356.aspx\">Myth:     Without \/3GB the total amount of memory that can be allocated     across all programs is 2GB<\/a>.     Virtual memory is not virtual address space (part 1). <\/li>\n<li><a href=\"http:\/\/blogs.msdn.com\/oldnewthing\/archive\/2004\/08\/10\/211890.aspx\">Myth:     Without \/3GB a single program can&#8217;t allocate more than 2GB     of virtual memory<\/a>.     Virtual memory is not virtual address space (part 2). <\/li>\n<li><a href=\"http:\/\/blogs.msdn.com\/oldnewthing\/archive\/2004\/08\/11\/212720.aspx\">Myth:     You need \/3GB if you have more than 2GB of physical memory<\/a>.     Virtual address space is not physical memory. <\/li>\n<li><a href=\"http:\/\/blogs.msdn.com\/oldnewthing\/archive\/2004\/08\/12\/213468.aspx\">Myth:     The \/3GB switch expands the user-mode address space of all programs<\/a>.     A program must request it before it gets it. <\/li>\n<li><a href=\"http:\/\/blogs.msdn.com\/oldnewthing\/archive\/2004\/08\/13\/214117.aspx\">Why     does Exchange recommend \/3GB if you have more than     1GB of physical memory?<\/a>     Bologna and cheese sandwiches. <\/li>\n<li><a href=\"http:\/\/blogs.msdn.com\/oldnewthing\/archive\/2004\/08\/16\/215089.aspx\">Myth:     The \/3GB switch lets me map one giant 3GB block of memory<\/a>.     There are still holes in the virtual address space. <\/li>\n<li><a href=\"http:\/\/blogs.msdn.com\/oldnewthing\/archive\/2004\/08\/17\/215682.aspx\">Why     is the virtual address space 4GB anyway?<\/a>     That&#8217;s what happens when you have 32-bit pointers. <\/li>\n<li><a href=\"http:\/\/blogs.msdn.com\/oldnewthing\/archive\/2004\/08\/18\/216492.aspx\">Myth:     PAE increases the virtual address space beyond 4GB<\/a>.     PAE is an extension for physical address, not virtual addresses. <\/li>\n<li><a href=\"http:\/\/blogs.msdn.com\/oldnewthing\/archive\/2004\/08\/19\/217087.aspx\">Myth:     In order to use AWE, you must enable PAE<\/a>.     The two are independent.     AWE is how programs access physical memory.     PAE is how the CPU accesses physical memory. <\/li>\n<li><a href=\"http:\/\/blogs.msdn.com\/oldnewthing\/archive\/2004\/08\/20\/217683.aspx\">The     curious interaction between PAE and NX<\/a>.     NX uses a feature available only in PAE mode. <\/li>\n<\/ul>\n<p> I&#8217;m not sure how successful this series has been, though, for it appears that even people who have read the articles <a href=\"http:\/\/www.ntwizards.net\/2004\/08\/22\/pae_3gb_huh\"> continue to confuse virtual address space with physical address space<\/a>. (Or maybe this person is merely mocking a faulty argument? I can&#8217;t tell for sure.) <\/p>\n","protected":false},"excerpt":{"rendered":"<p>A table of contents now that the whole thing is over. I hope. The oft-misunderstood \/3GB switch. It&#8217;s simple to explain what it does, but people often misunderstand. Kernel address space consequences of the \/3GB switch. An adverse consequence of the \/3GB switch. Myth: Without \/3GB the total amount of memory that can be allocated [&hellip;]<\/p>\n","protected":false},"author":1069,"featured_media":111744,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[26],"class_list":["post-38093","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-oldnewthing","tag-other"],"acf":[],"blog_post_summary":"<p>A table of contents now that the whole thing is over. I hope. The oft-misunderstood \/3GB switch. It&#8217;s simple to explain what it does, but people often misunderstand. Kernel address space consequences of the \/3GB switch. An adverse consequence of the \/3GB switch. Myth: Without \/3GB the total amount of memory that can be allocated [&hellip;]<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/38093","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/users\/1069"}],"replies":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/comments?post=38093"}],"version-history":[{"count":0,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/38093\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/media\/111744"}],"wp:attachment":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/media?parent=38093"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/categories?post=38093"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/tags?post=38093"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}