PAE - Revision history

TpUser0: If you have a choice…

2017-03-12T20:32:10Z

If you have a choice…

TpUser0: /* Processors */ typo

2017-03-12T20:24:01Z

‎Processors: typo

TpUser0: Ubuntu Documentation link

2017-03-12T20:23:06Z

Ubuntu Documentation link

TpUser0: /* Operating Systems */ corr.

2017-03-12T16:51:22Z

‎Operating Systems: corr.

TpUser0: /* Operating Systems */ corr.

2017-03-12T16:50:50Z

‎Operating Systems: corr.

TpUser0: /* Processors */ corr.

2017-03-12T16:35:14Z

‎Processors: corr.

TpUser0: /* Processors */ cat /proc/cpuinfo

2017-03-12T16:34:21Z

‎Processors: cat /proc/cpuinfo

TpUser0: /* Operating Systems */ typo

2017-03-12T16:33:42Z

‎Operating Systems: typo

TpUser0: /* Operating Systems */ Mac OS X 32-Bit

2017-03-12T16:32:43Z

‎Operating Systems: Mac OS X 32-Bit

TpUser0: /* Operating Systems */ 32-Bit clearer

2017-03-12T16:31:38Z

‎Operating Systems: 32-Bit clearer

@@ Line 50: / Line 50: @@
 The one series of processors with internal PAE support but without the CPU flag is the first generation [[Intel Pentium M (Dothan)|Dothan (Pentium M)]]. For this CPU, PAE can still be used with a modern Linux kernel when using the [[Kernel parameters|kernel parameter]] <code>forcepae</code>. (The second generation Dothan core and its successors include both CPU flags: <code>pae</code> and <code>nx</code>.)
-Note that using a PAE kernel on a system with less then 4 GB of memory will produce a certain overhead and thus has a small impact on performance.
+==Choice==
 ==See also==

@@ Line 48: / Line 48: @@
 Note: Processors which include <code>pae</code> in the list of flags also include <code>nx</code> (No eXecute), which is called the NX-Bit on Intel CPUs.
-The one series of processors with internal PAE support but without the CPU flag is the first generation [[Intel Pentium M (Dothan)|Dothan (Pentium M)]]. For this CPU, PAE can still be used with a modern Linux kernel when using the [[Kernel parameters|Kernel parameter]] <code>forcepae</code>. (The second generation Dothan core and its successors include both CPU flags: <code>pae</code> and <code>nx</code>.)
+The one series of processors with internal PAE support but without the CPU flag is the first generation [[Intel Pentium M (Dothan)|Dothan (Pentium M)]]. For this CPU, PAE can still be used with a modern Linux kernel when using the [[Kernel parameters|kernel parameter]] <code>forcepae</code>. (The second generation Dothan core and its successors include both CPU flags: <code>pae</code> and <code>nx</code>.)
 Note that using a PAE kernel on a system with less then 4 GB of memory will produce a certain overhead and thus has a small impact on performance.

@@ Line 55: / Line 55: @@
 * [https://packages.debian.org/wheezy/linux-image-686-pae linux-image-686-pae] (Debian wheezy)
 * [http://askubuntu.com/questions/19389/whats-the-meaning-of-pae-at-the-end-of-kernel-version What's the meaning of “-pae” at the end of kernel version?] (Ubuntu forum)
-* [https://msdn.microsoft.com/en-us/library/windows/desktop/aa366796(v=vs.85).aspx Physical Address Extension] (Windows Dev Center)
+* [https://msdn.microsoft.com/en-us/library/windows/desktop/aa366796(v=vs.85).aspx Physical Address Extension], Windows Dev Center
 * [https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=643012 Debian Bug #643012, Pentium M: Not possible to install PAE kernel]
 [[Category:Glossary]]

@@ Line 15: / Line 15: @@
 Non-PAE Linux kernels use <code>486</code>, while kernels for <code>686</code> most commonly default to PAE since around 2012. Mac OS X/Intel never officially supported 32-Bit non-PAE CPUs. The last Windows operating system to work on non-PAE CPUs is Windows 7 32-Bit.
-Note: 64-Bit operating systems don't use or require PAE (yet). In fact, x86-64 (also called amd64 and x64) does the reverse: current 64-Bit x86-CPUs (2003-2017) use a phyiscal address size of 48 bits, allowing 256 TB of memory to be addressed directly (2<sup>48</sup>). In the future, when this limit comes closer, this may be expanded to the full 64 bits. For now, as 48 bits are absolutely sufficient, it makes sense to not have to wire address lanes that will never be used anyhow. Looking into the past, processors such as the Motorola 68EC020 used 24 bits physically while reporting to be a 32-Bit processor to the software. This all makes sense when considering manufacturing costs and the assumption of not using it anyhow.
+Note: 64-Bit operating systems don't use or require PAE (yet). In fact, x86-64 (also called amd64 and x64) does the reverse: current 64-Bit x86-CPUs (2003-2017) use a phyiscal address size of 48 bits, allowing 256 TB of memory to be addressed directly (2<sup>48</sup>). In the future, when this limit comes closer, this may be expanded to the full 64 bits. But for now, as 48 bits are absolutely sufficient, it makes sense to not have to wire address lanes that will never be used anyhow. Looking into the past, processors such as the Motorola 68EC020 used 24 bits physically while reporting to be a 32-Bit processor to the software. This all makes sense when considering manufacturing costs and the assumption of not using it anyhow.
 ==Processors==

@@ Line 15: / Line 15: @@
 Non-PAE Linux kernels use <code>486</code>, while kernels for <code>686</code> most commonly default to PAE since around 2012. Mac OS X/Intel never officially supported 32-Bit non-PAE CPUs. The last Windows operating system to work on non-PAE CPUs is Windows 7 32-Bit.
-Note: 64-Bit operating systems don't use or require PAE (yet). In fact, x86-64 (also called amd64 and x64) does the reverse: current 64-Bit x86-CPUs (2003-2017) use a phyiscal address size of 48 bits, allowing 256 TB of memory to be addressed directly (2<sup>48</sup>). In the future, when the limits comes closer, this may be expanded to the full 64 bits. For now, as 48 bits are absolutely sufficient, it makes sense to not have to wire address lanes that will never be used anyhow. Looking into the past, processors such as the Motorola 68EC020 used 24 bits physically while reporting to be a 32-Bit processor to the software. This all makes sense when considering manufacturing costs and the assumption of not using it anyhow.
+Note: 64-Bit operating systems don't use or require PAE (yet). In fact, x86-64 (also called amd64 and x64) does the reverse: current 64-Bit x86-CPUs (2003-2017) use a phyiscal address size of 48 bits, allowing 256 TB of memory to be addressed directly (2<sup>48</sup>). In the future, when this limit comes closer, this may be expanded to the full 64 bits. For now, as 48 bits are absolutely sufficient, it makes sense to not have to wire address lanes that will never be used anyhow. Looking into the past, processors such as the Motorola 68EC020 used 24 bits physically while reporting to be a 32-Bit processor to the software. This all makes sense when considering manufacturing costs and the assumption of not using it anyhow.
 ==Processors==

@@ Line 46: / Line 46: @@
 This is the <code>cpuinfo</code> of a Dothan core Pentium M of the first generation. Even though it uses a 36-Bit physical address size, <code>pae</code> (as well as <code>nx</code>) is not listed among the provided processor features.
-Note: Processors which include <code>pae</code> in the list of flags also include <code>nx</code> (No eXecute), which is the NX-Bit on Intel CPUs.
+Note: Processors which include <code>pae</code> in the list of flags also include <code>nx</code> (No eXecute), which is called the NX-Bit on Intel CPUs.
 The one series of processors with internal PAE support but without the CPU flag is the first generation [[Intel Pentium M (Dothan)|Dothan (Pentium M)]]. For this CPU, PAE can still be used with a modern Linux kernel when using the [[Kernel parameters|Kernel parameter]] <code>forcepae</code>. (The second generation Dothan core and its successors include both CPU flags: <code>pae</code> and <code>nx</code>.)

@@ Line 20: / Line 20: @@
 To see if a specific CPU supportes PAE, list the contents of <code>/proc/cpuinfo</code>.
   processor	: 0
   vendor_id	: GenuineIntel

@@ Line 13: / Line 13: @@
 * Windows 8 32-Bit
-Non-PAE Linux kernels use <code>486</code>, while kernels for <code>686</code> most commonly default to PAE since around 2012. Mac OS X/Intel never officially supported non-PAE CPUs. The last Windows operating system to work on non-PAE CPUs is Windows 7 32-Bit.
+Non-PAE Linux kernels use <code>486</code>, while kernels for <code>686</code> most commonly default to PAE since around 2012. Mac OS X/Intel never officially supported 32-Bit non-PAE CPUs. The last Windows operating system to work on non-PAE CPUs is Windows 7 32-Bit.
 Note: 64-Bit operating systems don't use or require PAE (yet). In fact, x86-64 (also called amd64 and x64) does the reverse: current 64-Bit x86-CPUs (2003-2017) use a phyiscal address size of 48 bits, allowing 256 TB of memory to be addressed directly (2<sup>48</sup>). In the future, when the limits comes closer, this may be expanded to the full 64 bits. For now, as 48 bits are absolutely sufficient, it makes sense to not have to wire address lanes that will never be used anyhow. Looking into the past, processors such as the Motorola 68EC020 used 24 bits physically while reporting to be a 32-Bit processor to the software. This all makes sense when considering manufactoring costs and the assumption of not using it anyhow.

@@ Line 7: / Line 7: @@
 ==Operating Systems==
 Modern 32-Bit operating systems rely on Physical Address Extension and don't work without it. Those include (in alphabetical order):
-* Linux with a PAE kernel (ending with <code>-pae</code>)
+* Linux with a x86 (32-Bit) PAE kernel (ending with <code>-pae</code>)
 ** Debian with kernel package <code>linux-image-686-pae</code>
 ** Ubuntu starting with 12.04 LTS
-* Mac OS X/Intel
+* Mac OS X/Intel 32-Bit
 * Windows 8 32-Bit