jokim@jarthur.Claremont.EDU (John H. Kim) (10/30/90)
Thanks to the following people for their replies. I've
summarized for each topic. The person's abbreviation will
precede their comments. If the abbreviation doesn't show
up in a topic, (s)he didn't reply. (Apologies to anyone
who doesn't like how I abbreviated their name)
I'll be keeping this summary til about May. After that,
I'm gone. So if someone wants to make this available on
a more permanent basis, be my guest.
AJM: amichiel@rodan.acs.syr.edu (Allen J Michielsen)
DMD: Doug McDonald <mcdonald@aries.scs.uiuc.edu>
Dun: dunike!pikes!cjones@uunet.uu.net
JKG: genemans@eleazar.dartmouth.edu (Jan K. Genemans)
KJM: Kevin J Martin <sigma@rpi.edu>
Kum: "Rennolet (Kumar)" <rennolet@umn-ai.cs.umn.edu>
LS: lstowell@pyrnova.pyramid.COM (Lon Stowell)
RD: rdu@pruxe.att.com (Ranjan Dutta)
----------------------------
Word Processing
DMD: any
Dun: [WordPerfect will run okay on a 286/12, Word for Windows would
need 386/25 or greater]
JKG: 5 MHz 8088/8086 w/20M HD
KJM: [For simple programs] 4.77 MHz is fine.
Kum: PC-XT at 8MHz or faster. PC-AT at 8MHz if using background tasks
such as printing or spell-checking.
LS: 2-3Mbyte of RAM is o.k. just get [a large drive]
---------------
Database
JKG: Small Data Base (5-25k) -- 8 MHz 8088 w/20M HD
Medium Data Base (25k-200k) -- 12 MHz 80286 w/20M HD
Large Data Base (200k-1M) -- 16 MHz 80386SX w/40M HD
Very Large Data Base (1M+) -- 25+ MHz 80386DX w/80M+ HD
KJM: [hard drive is the important thing] ... extra megabyte of
memory used as a disk cache has incredible effects as well.
Kum: PC-AT at 8MHz or faster, fast hard disk [ESDI, less than 28ms]
JKG: Disk access speeds:
5 MHz 8088 70ms, 5 Megabits per second
12 MHz 80286 28ms, 5 Megabits per second
33 MHz 80386 20ms or less, 10 Megabits per second or more.
---------------
Spreadsheet:
Dun: Depending on on the size of the spreadsheet:
1) Home Budget/Checkbook : 16MHz 80386
2) Small Business Finance : 20MHz 80386
3) Large Business Finance : Cached 25 MHz or 33 MHz 80386
KJM: [286 good enough. Fast 286 if program uses graphics]
Kum: [Word Processing system + math coprocessor and about
1 extra Meg of memory]
JKG: Same as for Data Base. [Math coprocessor recommended
with Large and Very Large spreadsheets]
LS: Spreadsheets are cpu hogs. A 386SX with a Coprocessor
will beat a '386 without one
---------------
Editing Pictures
Dun: This depends more on the speed of your graphics adapter.
For the most part, any of the major brands will do just fine.
JKG: 12 MHz 80286 w/20M HD
KJM: VGA or SuperVGA ... at least a 286 for [speed]
Kum: [16-bit display adapter, some benefit with CPU in 20+MHz range]
---------------
CAD
DMD: 20 minimum, 25 or 33 is better
Dun: All the speed you can get.
JKG: [same as Kum, you really need a CAD minicomputer for the
complex things.]
KJM: [same as Kum]
Kum: full-blown system (as fast as you can go, 386/33+387 or 486).
[Can get by with] a 20MHz 386 with 4Meg of memory and a fast
disk (1-1 interleave, ESDI). ... need a BIG disk to hold all
your designs, such as a 200Meg or larger drive.
LS: get a '386 with a Coprocessor and LOTS of RAM...like 8 Mbyte
---------------
At what speed is a cache useful?
Dun: [25+ MHz, but might not be worth the money at 25 MHz]
JKG: 20+ MHz
KJM: [Cache becomes useful at above 20 MHz. 32K cache provides about
96% hit rate, while larger 256K cache can never exceed 99% (he's
not sure though)]
Kum: A cache would help you in all but the CAD and picture-editing, as
these applications and data would probably not fit in the cache.
LS: 16+ MHz
RD: The fastest memory (DRAMS) available right now works at
50 ns ( ~ 20MHz). So CPUs working above this speed will
definitely benefit from some memory cache.
AJM: I feel that memory cache's don't become effective at under
25 Mhz, unless a lot of wait states are involved in the
system design. Instruction cache memory starts becoming
advantageous at speeds over 16Mhz typically. The increase
is very marginal, unless it's done with static ram. Disk
cache memory starts becoming advantageous at about 12 Mhz,
IF the disk drive is fast. The slower the drive, the less
advantageous the cache.
Kum: My gut feeling is that a 386/20 without cache and without
interleaving is about 20 times as fast as an old, true-blue
PC (4.77MHz). With interleaving, you get about 24, with
cache 27, and a 386/25 without cache but with interleaving
is about 27 also. With cache a 386/25 is about 30, and a
386/33 with cache would be around 40.
---------------
Windows 3.0
DMD: 20 MHz is just enough - unless you want 256 colors,
then I suggest you look very carefully at bus designs
and video cards!
Dun: Windows is interesting in that it eats processor power
like some people eat french fries. You can never have
enough speed when using a Windows application it seems.
JKG: at least a 20MHz 386 system w/40 M HD, 4M RAM
KJM: get a 386 at 20+ Mhz ... and at least four MB of RAM.
RD: Windows 3.0 with one application running will behave just
fine in a 16 MHz machine. Even opening a second window will
not slow it down appreciably. However, if you want to work
with 4 to 6 windows open (eg. dos, word processor, spreadsheet,
communication, graphics/image and a page lay-out) and want
the background processes to work with any significant speed,
you would like the speed of 33 MHz machine. Higher speed
machines are essential for multitasking and very soon you
find out that you can not live without multitasking.
---------------
Additional Comments
Kum: Running Unix:
Minimum configuration is a 386SX with 4Meg of memory and
a fast disk. SCSI is preferred [shifts some work from CPU
to the SCSI controller]
KJM: For most programs, 25 or 33 Mhz is overkill. Trust me.
I bought a 33 Mhz system just because I could, and found
that the system's speed was limited by its peripherals.
I have very few programs that can really use a LOT of
processor power. Quattro Pro is a possibility, or MS Word 5.0.
If you don't know quite what you need, get a 386 system.
[386 is more flexibile. 286 okay if no heavy use planned]
JKG: [You need to be concerned with speed of graphics adapter for
Super VGA and up]
LS: One caution, don't even think of using memory attached to
cards on the bus. The standard AT bus is SLOOOOOOOOOOOOOOOOOW
compared to the main cpu. (These boards make o.k. RAM drives,
but are no faster than a good 1:1 disk controller.)
Get your memory right on the motherboard.
A 16 MHz 386 SX system is a fairly good compromise...less than
$2K with a good 80-140 Mbyte drive. Add at LEAST 2 Mbyte for
Windows 3.0...you won't really be happy with much less than 4 if
you use 3.0 though.....
RD: ...if you are planning for the future, multimedia is just around
the corner, and for that 33 MHz and higher might be desirable.
--
John H. Kim | (This space to be filled when I
jokim@jarthur.claremont.edu | think of something very clever
uunet!jarthur!jokim | to use as a disclaimer)