Gentoo Archives: gentoo-user

From: Richard Fish <bigfish@××××××××××.org>
To: gentoo-user@l.g.o
Subject: Re: [OT] Re: [gentoo-user] Intel Core Duo Processor - Anyone?
Date: Thu, 30 Mar 2006 04:48:00
Message-Id: 7573e9640603292043j2fa0f51cxd9bb1f9a75f32ea9@mail.gmail.com
In Reply to: Re: [OT] Re: [gentoo-user] Intel Core Duo Processor - Anyone? by Lord Sauron
1 On 3/29/06, Lord Sauron <lordsauronthegreat@×××××.com> wrote:
2 > www.alienware.com I beg to differ. I could have sworn I saw a laptop
3 > with more than 2G... where was it... wow! You appear to be right!
4 > Darn.. I could have SWORN I saw something with > 2G...
5
6 Actually, you are right. I neglected the monstrous Clevo laptop. Its
7 an AMD X2 with capacity for 2 optical drives plus 2 hard drives, up to
8 3G of memory, and a 200W power adapter. Weighs 12-15 lbs, _not_
9 counting the power adapter! This is acutally a Clevo design, sold by
10 Sager, AGearnotebooks, and many others. Alienware got it with a
11 customized case. All of the reviews I read on it basically said
12 "incredible performance, excellent display, but heavy, noisy, and
13 really hard to describe how large it really is".
14
15 I was actually considering purchasing this beast...but the noise
16 factor scared me off. Not really appropriate for a shared office or
17 conference room.
18
19 > compiler helps with the 64-bit part. It gets a bit technical, but
20 > there is a big difference between something made from the ground up as
21 > 64-bit versus something that was made 32-bit and just recompiled
22 > 64-bit.
23
24 For most applications, this is not true. The vast majority of C/C++
25 code that runs on a desktop system couldn't care less whether longs
26 and pointers are 32-bits or 64-bits in size. It is a compiler
27 function to deal with that. And it is also a compiler function to
28 determine whether 64-bit or 32-bit registers should be used for a
29 particular operation. FYI, gcc has supported non-x86 64-bit CPUs for
30 a long time, so gcc's 64-bit support is probably more mature than you
31 think. So are the applications...many open source applications were
32 ported and adapted (if necessary) to 64-bit sparc and alpha processors
33 back in the late 90s.
34
35 There are opportunities for some programs to take advantage of special
36 processor operations through assembly instructions. This is very
37 similar to how 3Dnow, MMX, SSE, et. al. make programs faster. So
38 there may be some specific optimizations for some operations that can
39 be improved over time.
40
41 An example of an application domain that could benefit from 64-bit is
42 encryption, because for key setups you need to calculate very large
43 numbers. Such numbers could be calculated about twice as fast with
44 64-bit operations vs 32-bit. *BUT*, this does almost nothing for the
45 actual data encryption itself.
46
47 A good resource on the 64-bit vs 32-bit issues is to look at AMDs
48 optimization guide for software developers. Chapter 3 is particularly
49 relevant:
50
51 http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/25112.PDF
52
53 -Richard
54
55 --
56 gentoo-user@g.o mailing list

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Re: [OT] Re: [gentoo-user] Intel Core Duo Processor - Anyone? Mike Myers <fluffymikey@×××××.com>