1 |
On 09/16/2011 09:36, Donnie Berkholz wrote: |
2 |
|
3 |
> |
4 |
> For anyone interested how the performance compares to amd64 in more |
5 |
> comprehensive tests, check out the slides from the Linux Plumbers |
6 |
> Conference (particularly 14-21): |
7 |
> |
8 |
> http://linuxplumbersconf.org/2011/ocw/proposals/531 |
9 |
> |
10 |
> In summary, on those benchmarks it looks like a small global win (maybe |
11 |
> 5%) on integer calculations with a few huge wins of ≥25%, but a net loss |
12 |
> around 5% pretty much globally for floating-point calculations. |
13 |
> |
14 |
> Most people probably do a lot more integer calculations unless they're |
15 |
> science geeks like me, plus it should have lower memory use, so my |
16 |
> understanding is that it probably makes sense to switch to x32 no matter |
17 |
> what you're using now (x86 or amd64). |
18 |
> |
19 |
> Mike, would you agree? |
20 |
|
21 |
|
22 |
Again, extremely similar to MIPS cases from a few years ago. While even n32 |
23 |
is fairly stable in Linux (last few years, at least), the idea was always |
24 |
that in an ideal multilib scenario, you'd use pure 32bits (MIPS o32) in very |
25 |
limited cases (programs that just didn't work in either n32 or n64), n32 for |
26 |
a majority of the system, and pure 64bit (n64) for specific applications, |
27 |
like databases, crypto, or science applications. |
28 |
|
29 |
That's supposed to provide the balance so that float-intensive apps can use |
30 |
pure 64bit w/o penalty, but things that simply don't need 64bits' full power |
31 |
can make use of n32/x32. |
32 |
|
33 |
And yeah, lower memory use because the size of codewords is smaller in |
34 |
memory overall. |
35 |
|
36 |
Anyone wanting to compare x32 and n32 can see the old n32 ABI guide here: |
37 |
ftp://ftp.linux-mips.org/pub/linux/mips/doc/ABI2/MIPS-N32-ABI-Handbook.pdf |
38 |
|
39 |
-- |
40 |
Joshua Kinard |
41 |
Gentoo/MIPS |
42 |
kumba@g.o |
43 |
4096R/D25D95E3 2011-03-28 |
44 |
|
45 |
"The past tempts us, the present confuses us, the future frightens us. And |
46 |
our lives slip away, moment by moment, lost in that vast, terrible in-between." |
47 |
|
48 |
--Emperor Turhan, Centauri Republic |