Mailinglist Archive: opensuse (686 mails)

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Re: [opensuse] 64 bit vs 32 bit RAM consumption
  • From: "Carlos E. R." <robin.listas@xxxxxxxxxxxxxx>
  • Date: Tue, 23 Jul 2013 20:37:22 +0200 (CEST)
  • Message-id: <alpine.LNX.2.00.1307232029560.5519@minas-tirith.valinor>
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El 2013-07-23 a las 11:09 -0700, John Andersen escribió:
On 7/23/2013 5:44 AM, Carlos E. R. wrote:

If that data space is large, the impact can be significant.

Except that the impact isn't likely to be significant at all.

The overwhelmingly vast majority of data in any system is not concerned with an
integer here or
a float there. The bulk of data, by a wide margin, is a string, or a block of
text.
In that world, a byte is still a byte.

It can be gigabytes if the app does integer math on large data arrays. I did a proof of concept program somewhere that demonstrated the idea, and I did found time ago an application (commercial?) with this issue.


With bigger registers you can move data twice as fast, because the load time
for 32 bits is
the same for 64 bits.

Huh, not quite.

If you have to add 2 and 3 it will take the same time on both archs. 64 bit is not faster, it is larger. Compare a road truck of 6 wheels to another of 12 wheels and double length.


The programs instructions, your code pages, is the thing that might grow the
most.
Presumably most of that is optimized, but I really don't know for sure.




- -- Cheers

Carlos E. R.
(from 11.4, with Evergreen, x86_64 "Celadon" (Minas Tirith))

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