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- Newsgroups: comp.sys.ibm.pc.misc
- Path: sparky!uunet!ukma!netsys!agate!dog.ee.lbl.gov!news!manta!discar
- From: discar@nosc.mil (Joe Discar)
- Subject: Re: 486 vs. 386
- Message-ID: <1992Nov10.212830.29724@nosc.mil>
- Organization: Naval Ocean Systems Center, San Diego
- References: <BxFpHv.8zB@news.orst.edu> <1992Nov9.200839.27999@exu.ericsson.se>
- Date: Tue, 10 Nov 1992 21:28:30 GMT
- Lines: 67
-
- In article <1992Nov9.200839.27999@exu.ericsson.se> exuhag@exu.ericsson.se writes:
- >Derek Schott writes:
- >>
- >>After watching the market trend, I have the funniest feeling that
- >>everything has about hit rock bottom. A lot of people keep saying
- >>that the introduction of the i586 is going to severely cut the
- >>prices of both the 386 and 486 machines. Although it might drop
- >>the prices at first, I don't see why it is going to cut them so
- >>much.
- >
- >Not to mention that very few people actually need a 586 (aka Pentium).
- >How many people--excepting ray-tracing fanatics and people who do
- >serious number crunching--have had any speed problems with a 33 MHz
- >486? For the mass-market, the Pentium is a solution waiting for
- >a problem (like CD-I). I can't see people scrambling to buy them,
- >unless they are one of the rising number of buzzword addicts.
- >
- >--
- >James Hague
- >exuhag@exu.ericsson.se
-
-
- I have a prediction about what the i586 will do to the PC market. You
- see, I am an avid upgrader--having gone through ALL iterations of the
- 80x86, from 8088 to 486-66DX-2. Yes, there has been an increase in
- *speed*... but there is more to what a new CPU does to the industry.
-
- Consider a three-tine fork: Speed, Software, and Interfaces. When the
- 8088 was king, the XT bus was popular. The 80286 didn't "kill" 8088
- software (real-mode software was untouched)... but it introduced the 16-bit
- bus.
-
- The 80386 began to kill the 8088 software world. Windows 3.1 is nailing
- down the coffin. It has also, but not quite, killed the XT Bus--and
- made "16 bit" cards the defacto standard (if anything, just so that
- interrupt lines could be doubled). Speed-wise, the 486 is king--70
- times faster than the 8088.
-
- What hasn't changed? The ISA bus is still predominant. But the 486
- will not change it. Why? Because until recently, nobody really *notices*
- that there is a problem with the ISA bus.
-
- But the 486 can access 4 Gigs of memory and supports virtual memory
- (like the 386). But NOW, memory is cheaper--32 megs of RAM in a PC is not
- unheard of these days.
-
- So what's the problem? The ISA bus only addresses 24 bits--or roughly
- 16 megabytes. If memory-mapped I/O is needed (such as in a 24 bit
- NTSC video digitizer), it can only map the I/O at under 16 megs (this can
- also affect some software when virtualizing RAM through a hard disk
- controller). In effect: it reincarnates the infamous 640K barrier at
- 16 megabytes!
-
- The 586 is a new architecture, and I predict that it will introduce or
- at least mandate a 32 bit (or 64 bit) bus. This will, in essence,
- "kill" the 386/486 as it exists now (until motherboards are made for
- a wider bus).
-
- All of the previous is my humble opinion. But I have been beating my
- head against the 16 meg barrier for almost two months now.
-
- Change will happen. By any means necessary.
-
- -> joe <-
-
-
-
-