Re: [tlug] Is Prime PC a good enough place to buy a PC

[Tobias Diedrich <ranma@example.com>]

Ian Wells wrote:

> The last 486 was a DX2-133, I believe. Original Pentiums certainly went to
> P133, possibly P166, PPros to 200MHz. PIIIs are difficult to quantify, cos
> something based on the PIII core was in their Pentium Ms. But I've certainly
> used PIII-Xeon-800s. Somewhere in that sequence they went from 1 instruction
> per clock to 2 - the first Pentiums, maybe?
> 
> I've used 8088s, 188s and 286s but it's far too long ago to remember about
> such things...

Hmm... From the top of my head (currently without telephone+internet
until at least 3. October :():

8086:  16bit, max. 1MB of address space, 64K segments
80186: Basically an 8086 with integrated peripherals (PIC, PIT,
       etc.), slightly incompatible to IBM PC architecture.
80286: Introduced protected mode, still 16bit, max. 16MB, supports
       paging of segments
80386: 32bit, introduced MMU & page based paging, 4GB address space
80486: first x86 RISC/CISC-Hybrid (8086-80386 were CISC),
       cpuid instruction was added to late models
Pentium: Superskalar architecture with two pipelines (max. 2
         instructions per clock), MTRRs, built-in performance
         counters, timestamp counter, later models got MMX
PPro: Optimized for 32bit mode => bad W9x/16bit performance
      IIRC first x86 cpu designed with SMP in mind, introduced APIC,
      onchip second level cache (but with seperate dies, making it
      difficult to manufacture), Either PPro or Pentium2 were the
      first to cludgily support more than 4GB of RAM (but not per process
      of course), not sure which one

> PIIIs were, in my experience, much better at instructions per cycle than the
> PIIs. And the P4s as well - the original P4s had faster clock speeds but
> were a step down in performance on the best PIIIs, and even now don't seem
> to perform as well as their clock speed would suggest. Compare a P4 2.8 with
> a mobile Pentium 1.7 laptop, for instance; there's not anything like a 50%
> improvement - and AMD are competing with their made-up
> clock-speed-equivalency numbers which are now tending towards 2x the actual
> chip speed.

Not sure about the differences from PII to PIV, but AFAIK the PIII
got some new multimedia enhancement over the PII (SSE? or MMXext?),
which made quite a bit of a difference for apps like MPlayer...

-- 
Tobias						PGP: http://9ac7e0bc.uguu.de
Mail over UUCP over Bicycle+Train