Re: P4 VS. Athlon

["Bryan J. Smith" <b.j.smith@xxxxxxxx>]

Andy wrote:
> Looking to build a new system and was wondering if
> anyone had experience with either the P4 or Athlon and
> Linux??

I could go into the design aspects of the P4, but let's just say
that the price is not worth it, let alone the current Rambus-only
mainboards for it (ServerWorks will have DDR SDRAM chipsets out for
the P4 near the end of the year).  When it comes to engineering apps
and high precision floating point, the P4 just tanks it versus the
Athlon.  Not just MHz for MHz, but even again the MHz advantage of
the P4.  Even basic applications are not safe as Ziff-Davis found
equally configured Micron Athlon 1.33GHz and Dell Pentium IV 1.7GHz
systems perform about the same, but differ in cost by ~$1,000 (and a
only 1.5GHz Dell model loses to the Athlon on every single
benchmark, especially at most games and engineering applications by
as much as 24%!).

So your best "bangs-for-the-buck" are P3 or Athlon, although the
Socket-370/GTL+ P3/Celeron platforms is limited to 1GHz CPUs where
as the Socket-A/462/EV-6 Duron/Thunderbird/"Athlon 4" platforms are
available at upto 1.33GHz speeds (and will support future ones as
well).

Given the price of the low-cost AMD Duron, and its overwhelming
performance advantage for the Celeron, I do not consider the Celeron
a "good option" anymore.  Even the higher-end AMD Thunderbirds are
dropped below $100 now.  So, I have trouble recommending the P3,
unless you were going dual-processor.

I think your only delima will be what mainboard to buy.  I offer the
following "recommendations" as you look at different mainboards:

1.  If you go ViA chipset (for either AMD or Intel), be sure to get
a mainboard with the latest 686"B" southbridge and Ultra100
support.  Not so much for speed, but for efficiency (ViA's 596B/686A
Ultra66 chipsets were no faster than the 586/596A ones) and
compatibility with Linux.  You'll want to use either the 2.4 kernel
or a 2.2 kernel with Hendrick's IDE backport for maximum performance
and reliability (although _avoid_ Western Digital drives with ViA
chipsets).

2.  If you decide on AMD, you'll want to go with the newer ViA
KT133A or AMD 760 chipsets as the KT266 still hasn't come out on
boards yet.  The KT133A is a PC133 chipset with 266MHz FSB support
for CPUs -- which means the memory and FSB run synchronous (unlike
the previous KT133 which only supported 200MHz FSB CPUs).  The AMD
760 supports the newer DDR SDRAM parts with many benchmarks showing
DDR SDRAM adds ~10-15% performance on the Athlon platform.  When the
KT266 starts appearing, some mainboards should sport both memory
slots, so the user can choose whether or not to use them -- although
ViA has been taking criticism in early reviews of the KT266 versus
the AMD 760 (where the KT266 with DDR seems no faster than the
KT133A with SDR).

3.  If you decide on Intel, you can "future proof" your decision by
going with the newer ViA Apollo Pro266 chipsets where the mainboard
sports both SDR (i.e. "regular") 168-pin SDRAM DIMM slots as well as
DDR 184-pin SDRAM DIMM slots.  Most enthusiast sites are finding
that DDR on the older GTK+/P3 platform is not a big deal because the
FSB is still stuck at 100-133MHz (whereas Athlon is 200-266MHz). 
Besides adding DDR SDRAM support, the Pro266 adds expanded support
for SDR SDRAM including 512MB IC parts and more additional bit
widths (i.e. you're going to have a hard time finding a SDRAM that
isn't supported ;-).

[ See my elug-hardware post on this for more info:
http://www.zepa.net/hypermail/elug/hardware/2001/02/0008.html ]

4.  The common, "commodity" SDRAM platform for Intel is the i815
chipset.  The i815 chipset has integrated video, audio and LAN,
although it is up to the manufacturer to break pins out for each. 
There is an AGPx4 slot option on most i815 mainboards, allowing the
end user to upgrade.  Probably the "major limitation" to the i815 is
the memory support, only upto 512MB using 2x256MB modules.  And even
then the SDRAM modules that you can use are limited (although
becoming more commonplace), with ECC and registered NOT an option. 
Hence, the old i440BX and i440GX chipset can still be found, usually
with an off-board Ultra100 disk controller (since the old PIIX4
southbridge only supports Ultra33).

5.  If you want to stick with Intel chipsets, there are several
options.  If you have money to burn, then buy all means, go RDRAM
and i840.  It sports dual-memory channels and one 64-bit PCI
channel.  The downside to RDRAM is the current size limitations of
RDRAM and the i840 will only allow you to upgrade to 1GB (with 4
pieces).  And if you go i820, that means only 512MB (with 2
pieces).  For the P4, you _have_to_go_ i850 which is _only_RDRAM_.

6.  Of course, when you start looking at the i840 and RDRAM,
ServerWorks chipsets are no more expensive.  ServerWorks, formerly
Reliance Computer Corporation (RCC), has made chipset for large OEMs
(IBM, Compaq, Dell, etc...) for years.  Now they sell chipsets to
end-user mainboard manufacturers -- including Intel themselves
(since they lack a "high-end" chipset that supports >2GB of SDRAM). 
The "big plus" with ServerWorks is the sheer I/O support, there is a
1GBps bridge between the northbridge and southbridge (even ViA and
Intel's latest are only 266MBps) which allows for dual 64-bitx66MHz
PCI busses (in addition to a 3rd, legacy 32-bit PCI bus).  It also
allows upto 4-way, 16 slot SDRAM memories for upto 16MB support. 
But the ServerWorks chipsets are definately designed with servers
and cluster nodes in mind, requiring ECC Registered PC100/133
memory, having a poor AGP implementation (most mainboards don't
bother putting it on-board) and only support for Ultra33 (as most
users will either put SCSI or a _real_ ATA RAID controller
on-board).

Regarding #2 & #3, DDR SDRAM is very commodity now.  You can get
quality, 266MHz DDR (aka "PC2100") SDRAM for as cheap as SDR SDRAM. 
Even Micron-brand Crucial 256MB DDR SDRAM sticks are only $66!  So
DDR is not a bad option, especially with Athlon and the AMD 760
where the FSB can take advantage of the bandwidth.

Regarding #3-6, the SDRAM v. RDRAM issue is up you to decide on. 
With Intel's SDRAM mainboards, you're limited in options and
expansion room.  With ViA you've got more flexible options, but they
are all P3-only (and no P4 is planned because Intel will not share
the info).  P4 is RDRAM only, at least until ServerWorks releases a
DDR SDRAM mainboard later this year.

As far as "recommended mainboards," for the Athlon, I have used:

CHEAP:  <$90, Abit KT7E
This is an older, 200MHz FSB only KT133 mainboard combined with the
newer, 686B southbridge with Ultra100.  This makes a perfect Duron
and 200MHz FSB Thunderbird (through 1.3GHz) chipset.

SOLID:  ~$140, Abit KT7A-RAID
Newer 266MHz FB, KT133A+686B that has tripple voltage regulation and
easily tames even the latest 266MHz FSB Thunderbirds (through
1.33MHz).  Also includes a Linux-compatible HPT370 second IDE
controller.

There are other KT133A+686B-based solutions as well, and many are
lower costing, although you must bewary of the mainboards with extra
IDE controllers using the Promise Ultra100 chipsets (like Asus'
products).

As far as Intel P3, Tom's Hardware just released a new review of 10
different Apollo Pro266-based mainboards.  Two of them can use
either existing SDR or newer DDR SDRAM:
http://www4.tomshardware.com/mainboard/01q2/010430/index.html

In addition to the AMD 760 and forthcoming ViA KT266 DDR SDRAM
chipsets for Athlon, the ALi Magic 1 was the first DDR SDRAM chipset
for Athlon.  Unfortunately, it seems lackluster on performance and
has reported compatibility issues (much like the ALi Aladin V did
for the Pentium generation).  Tom has a review of several of these
mainboards here:
http://www4.tomshardware.com/mainboard/01q2/010509/index.html

For i815, Pro266 and other reviews, just do a search.  As far as P4,
the cost is up to you but be sure to run with the latest distros
(otherwise the P4 isn't supported).

-- TheBS

-- 
Bryan J. Smith, President        mailto:b.j.smith@ieee.org
(407)366-7013 pager:(888)694-5793 chat:thebs413@AOL/MS/Yho
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