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Re: off topic : Pentium : std,mmx,pro,II



This is really off topic, but might interest most of you.

On Sun, 01 Mar 1998 11:42:24 +0200, Erez Doron <erez@savan.com> wrote:

>Hi
>
>sorry for being a little off topic, but i want to
>a new computer and i would like to know
>if i should invest more money and buy pentium II or ppro
>instead of P+MMX
>
>what is the diference ?
>
>I've heard  that P II is PPRO+MMX
>is that right ?
1. P II = PPro code + MMX enhancements
2. PII L2 cache runs at 1/2 clock speed, while PPro L2 cache runs at
full clock speed. Future PII's will also have a full clock speed L2
soon (slot 2 PII's)
3. Biggest PPro L2 cache is 1MB, while PII L2 cache is 512KB. Again,
this will change soon (slot 2 PII's).
4. PII Slot 1 supports 2-way SMP, while PPro supports more. Again,
slot 2 solves this.
5. PPro handles some 16 bit code worse than Pentium (!), while the PII
cures that.

Until the 450NX chipset is officially out in April 15, the PPro is
intel's preferred product for high end SMP machines for high workloads
due to the 4-way (and up) SMP, and the larger and faster L2 cache.

So in general, forget PPro.

In April 15, lots of new stuff will be announced (see
http://sysdoc.pair.com). If you don't mind waiting, you'll see:

1. 440BX chipset, with 100MHz motherboard speed (if you buy a 100MHz
PII).
2. 100MHz bus speed PII's for 440BX.
3. 450NX SMP chipset for Slot 2 PII's.
4. Slot 2 CPU's for the 450NX chipset.
5. 440EX/440LXR low end chipset and PII's with no L2, to kill the
Socket 7 market (Pentium, K6, ...)

>and what is the diference between Pentium and PPRO ?
The Pentium core (Pentium, MMX) vs. the PPro core (PPro, PII) are
radically different. The Pentium core issues UP TO two instructions on
every clock, while the PPro core breaks x86 instructions into several
internal uOps (micro-ops), which are simpler to execute, and can run
up to 5 of these in parallel. It can run OOO (out-of-order), and
generally can achieve 50% more work for the same clock cycle than a
Pentium core. Considering the fact that the PPro core can
technologically achieve a 30% higher clock rate than a Pentium core
**ON THE SAME MANUFACTURING PROCESS**, it is in total almost twice as
fast as a Pentium, for the same 0.35micron process. That's why top
0.35u Pentium was 233Mhz, while the top PII was 300MHz. ofcourse, with
0.25u, both chips scale up.


>Regards
>Erez.

Udi