On Wednesday February 26 2003 11:23 am, Seedkum Aladeem wrote:
> > While there's already 64 bit production machines, that use
> > gigs of ram, there's also already Linux performance optimized
> > kernels for them. IIRC, the kernels were ready before the
> > systems were. OTOH, before you'll see 64 bit desktops systems,
> > 512 mb of ram will still be overkill.
> Thanx Tom,
>
> This suggests that the performance penalty is brought about because
> of hardware limitations (i.e. CPU architecture) and not
> artificially introduced by sloppy memory management software. This
> suggests that some register somewhere in the CPU is not full 32
> bits long. I thought 32 bits of address give 4G of address space
> and not 1G.
>
> Maybe AMD should make 32 bit CPUs address the full 4G before going
> to 64 bit CPUs.
>
>
> Seedkum
Well, you're straining the limits of my ability to explain it
further ... mainly cause I dunno either ;)
I will say it's not so much "hardware limitations (i.e. CPU
architecture)", but has more to do with mathematics... in the realm
of hexadecimal numbers, and 2's complements, 32 things taken so many
ways (permutations and combinations).
It's only been a few years since the 'other OS' even graduated
from 16 bit computing, and as I understand M$ isn't there yet. Mostly
due to tryin to support legacy applications. Linux has always been
capable and willin to re-write software. There's been proprietary
UN*X OS's and applications that have long been 64 bit capable.
Hardware design isn't the big problem, user non-acceptance of change,
and willing acceptance of hardware is probly the bigger factor.
Many might remember the 2000 hoopla that all computers would start
messin up due to not bein able to recognize the difference between
1900 and 2000 dates. My brief self taught foray into programming (C,
C++) at least aquainted me with the fact that dates were stored as
code numbers (even on M$/DOS OS's) and the real limitation was around
2037 when 32 bit systems would barf on higher numbers than 32 bit can
address. The 32 bit mathematical limit just runs out of possible
numbers in row and column (matrix) addressing.
Same goes for memory arrays (ram), altho there are some kludges
that can be employed to get 32 bit kernels further. BUT, that's where
the performance hit comes in. So, at least in my understanding, it's
not an OS or user accepted hardware limit, as much as it's just the
axioms of mathematics at base 16 (hexidecimal), 2's compliment, with
just 32 bits to work with.
BTW, I believe filesystems are also governed by the same
mathematical laws and bits ;) I'm mostly doin some educated guessing
about all the above, Civileme, Juan, Warly, or Todd probly knows.
--
Tom Brinkman Corpus Christi, Texas
Want to buy your Pack or Services from MandrakeSoft?
Go to http://www.mandrakestore.com
