Talk:Long mode

Physical size of 264 bytes
The article states that "For the time being, it is impractical to equip computers with sufficient memory to require a full 64 bits." This is something of an understatement. Assuming that current (as of 2014) DRAM densities can provide 2×512Mb on a single 12×9mm IC chip, this gives a density of about 9.5 Mbit/mm$2$ or about 1.2 MB/mm$2$. Thus 2$64$ bytes would require about 14.8 million square meters of IC real estate (using current technology). Even assuming that we can increase memory densities another 10,000-fold within the next few decades, this would still require about 1,480 m$2$ of IC space. So I don't see any single CPU ever directly addressing this much total memory space, at least not within my lifetime. — Loadmaster (talk) 22:51, 13 February 2014 (UTC)


 * Yeah, but slice that 1,480 m$2$ of IC space into 1 m$2$ sheets and stack them on top of each other... Let's say that each layer is 2 mm thick –  that results in a stack about 3 m high.  I'm not saying that's actually going to happen, but from that perspective it might be doable; just remember the old mainframes, which had refrigerator-size boxes as their main components. :) &mdash; Dsimic (talk | contribs) 23:01, 13 February 2014 (UTC)


 * Yes, but those mainframes only had about 2$24$ bytes of physical memory, which were originally in magnetic-core memory form (and which were 3-dimensional stacks of memory planes). But 2$64$ bytes is a vastly larger amount of memory (12 orders of magnitude), and my point is that it is probably too large to actually be contained in a single physical memory unit, at least with IC technology in the foreseeable future. Yes, I expect that 3-dimensional circuits are eventually going to be used to solve the problems of quantum noise, but the reasons it has not yet been successful include the manufacturing cost, failure rates, and enormous heat dissipation problems. — Loadmaster (talk) 19:12, 19 February 2014 (UTC)


 * Please don't get me wrong, I'm not trying to argue with you, :) but we should remember that many things looked way too big at some point in time – just as 640 KB looked more than enough, probably at some point in time we'll be over even 264 bytes of RAM. &mdash; Dsimic (talk | contribs) 19:45, 19 February 2014 (UTC)

External links modified
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I have just added archive links to 1 one external link on Long mode. Please take a moment to review my edit. If necessary, add after the link to keep me from modifying it. Alternatively, you can add to keep me off the page altogether. I made the following changes:
 * Added archive https://web.archive.org/20120214231920/http://developer.amd.com/pages/123200367.aspx to http://developer.amd.com/pages/123200367.aspx

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Contested deletion
This page should not be speedily deleted because the stated reasons are not among those supported for speedy deletion. Jeh (talk) 09:48, 17 May 2017 (UTC)