Subject: Performance of G94W (summary)

From: <[email-masked]>
Date: Fri, 20 Dec 1996 13:47:48 +0200

Dear CCLers,

Some days ago I posted the following question:

>
> Dear CCLers,
>
> I'm going to buy a new PC with 64 MB RAM and a 4 GB hard disk in order
> to run G94W. I would like to know what is the best combination of CPU
> and operating system for this program, among the following:
>
> Pentium 200Mhz with Win 95
> Pentium 200Mhz with Win NT 4.0
> Pentium Pro 200 Mhz with Win NT 4.0
>
> If you have any experience on these systems, plese let me know.
> I' ll summarize if there is enough interest.
>
>                               Gianfranco
>
Many thanks to all those that replied to my question. In particular I wish
to thank Morten Langaard of the Roskilde University, Denmark, who gave me
the answer I was looking for.
Here it is a brief summary:

According to Morten G94W runs fine with Win NT 4.0 (it should be remarked
however that Gaussian Inc. releases G94W for Win 3.1x and Win 95 only).
His 200 Mhz Pentium Pro runs G94W jobs about 3 times faster than his 120Mhz
Pentium (which means about a 50% extra on a Pro processor compared to a
common Pentium). According to Morten this may be mainly due to the L2 cache
on the Pro, although he does not exclude that other factors (better processor
design, board, disks, etc.) may also play an important role.
Of course since G94W is a 16 bit Win 3.1x application you want exploit the
performance of the Pro architecture to the maximum. If you want maximum
performance you should use Linux or FreeBSD as OS and get the appropriate
version of G94.
The use of Win 95 has been discouraged by several people. The 16 bit code
still present in Win 95, the recent file system, and the conscious decision
on the part of the designers to emphasize foreground processes over all
makes it less than optimal platform. Programs like G94W that uses substantial
amounts of memory will eat all your resources under Win 95. Moreover Win 95
is less stable than Win NT 4.0.
In conclusion one should buy a 200Mhz Pentium Pro with Win NT 4.0, because
it cost only slightly more than a pentium, and performs like a "300 Mhz
Pentium" with G94W.

		Merry Christmas and happy new year to all CCLers
				Gianfranco

Prof. Gianfranco Ercolani
Dipartimento di Scienze e Tecnologie Chimiche
Universita' di Roma Tor Vergata
V. della Ricerca Scientifica
00133 ROma---Italy
E-mail: [email-masked]