SUMMARY: LX/classic performance

From: James Ashton (jaa101@deakin.anu.edu.au)
Date: Thu Aug 05 1993 - 10:35:40 CDT


I Asked:

>Assuming I don't need ISDN or CD quality sound, why would I buy a
>Classic or an LX? Local pricing means that an LX is cheaper for us
>than a Classic and an IPX is cheaper still. We may even need to pay
>extra to downgrade LX/Classics to Solaris 1.1! Given the above, the
>following table must be misleading, right?
>
> SPECint92 SPECfp92
> Classic/LX 26.4 21.0
> IPX 20.8 21.2
>
>The IPX figures are inflated by the use of 64MB of RAM but the
>Classic/LX figures are inflated (especially fp) by the use of special
>compilers. I'd appreciate information on any side-by-side comparisons
>people have made between the two machines which might give a better
>insight into the situation.

There were a range of responses leaving me with the impression that
it's a close call as to which machine is faster. Those who suggested
otherwise did not back up their opinions with data or reasoning. As
always, which machine is faster for you depends on what kind of
programmes you plan to run. The major points are:

LX/Classic may be a little faster than IPX for integer work.

IPX may be a little faster than LX/Classic for floating point work.

IPX has a much bigger cache (64KB) than LX/Classic (2KB data, 4KB
instruction).

LX/Classic have more hardware contexts (64) than IPX (8).

Weitek sells a Power uP which is a plug in replacement for the
processor in IPX (and SS2). For US$1K5 IPX gets about 1.5 times
faster. Shipping begins in mid September [I already have 3 on order].
It seems unlikely that an equivalent option for LX/Classic will be
available in the near future.

If you run LX/Classic with the shipped Solaris 2.[12] you may lose
around 10% of performance over Solaris 1.1. Solaris 2.[3-9] should
progressively close the gap.

IPX maximum memory is 64MB whereas LX/Classic can go to 96MB.

LX/Classic have fast SCSI2 (at 10MB/s) so disk throughput *can* be
twice as fast as IPX (5MB/s) with the right disk drives.

LX video (GXplus) can support double buffering or 1280x1024 resolution
(with suitable monitors) simply by adding 1MB VRAM.

Classic graphics are much slower than IPX although LX graphics are
probably equal to or a little faster than IPX.

LX (but *not* Classic) includes ISDN and CD quality sound.

Many people can buy LXs for less than IPXs. Check your local price
list.

When upgrading from an IPC, IPX is likely to be the cheapest option.

LX/Classic have a built in UTP tranceiver but with IPX you need to buy
a tranceiver to connect to an ethernet.

IPX uses the sun4c architecture which may soon cease production. The
LX/Classic use the sun4m architecture which is likely to have OS
support from Sun for longer.

Thanks and glory go to:

cogan@mso (Bruce Cogan)
glenn@uniq.com.au (Glenn Satchell - Uniq Professional Services)
John DiMarco <jdd@db.toronto.edu>
fabrice@cisk.ATMOS.Ucla.EDU (Fabrice Cuq)
exudnw@exu.ericsson.se (Dave Williams)
exudnw@exu.ericsson.se (Dave Williams)
Mike Raffety <miker@il.us.swissbank.com>
hargen@sybus.com (Bill Hargen)
szh@zcon.com (Syed Zaeem Hosain)
john@oncology.uthscsa.edu (John Justin Hough)
ericb@telecnnct.com (Eric Burger)
Pat Cain (Denver) <pjc@denver.ssds.COM>
eckhard@ts.go.dlr.de (Eckhard Rueggeberg)

--
James Ashton						  System Administrator
VK1XJA					     Department of Systems Engineering
Voice +61 6 249 0681	  Research School of Physical Sciences and Engineering
FAX   +61 6 249 2698				Australian National University
Email James.Ashton@anu.edu.au			   Canberra ACT 0200 Australia



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