mdb@abcom.ATT.COM (5013 ) (10/20/90)
I was unable to send this direct so here goes... John H. Kim: > How much is sufficent for word processing? Organizing a > database? Calculating a spreadsheet? Editing pictures on > a paint program? Designing a cruise missle on a CAD program? > Speed of the CPU is not the only thing you need to consider since these machines typically spend much of their life waiting on the user. I feel that you need to also consider the speed of the peripheral devices such as: 1) Hard Drive 2) Monitor This is due to the fact that most bottle-necks in the PC areana revolve around these two issues. > At how many MHz does a memory cache become advantageous? > What speeds would be considered overkill for the above > applications? How about programs that don't fall into the > above categories (like Windows 3.0)? > Memory cashe is used mostly in database applications due to the amount of data being retreive on slow hard drives. Speed overkill, IMHO, occures most often in database applications where data entry is the determining factor. In spead sheets and machine instruction intensive applications ( Windows, CAD/CAM ) are being used then CPU speed coupled with a math coprocessor will make a significant difference to the user. > And what else can you do with expansion slots aside from > memory expansion, video card, drive controller, and (maybe) > a mouse? > Some of the goodies ;-) that you might consider to fill out those empty expansion slots include: 1) Joy sticks 2) Fax boards 3) 9 track interface boards 4) etc.... Hope this will help... If would like to discuss these furthure I can be reached by phone: 415-224-3030 Mike Barnes AT&T Communications
ssingh@watserv1.waterloo.edu (The Sanj - ISman (iceman)) (10/21/90)
>> How much is sufficent for word processing? Organizing a >> database? Calculating a spreadsheet? Editing pictures on >> a paint program? Designing a cruise missle on a CAD program? >> word processing: depends what you mean. If you mean text only, you will be fine with 8 Mhz Xt. If you are using extensive images in your work (assuming WP 5.1 or equivalent), you should get a faster (at least 16 Mhz) CPU; ie. I have a 386sx-16. I am working with a 4-meg WordPerfect file. When I paste in a new image to replace a previous one, the drive grinds away for 10 minutes or more while it is updating all of the temporary files. I usually get a drink while this is going on. data base: this is more dependent on your hard drive... spread sheet: here you have to juggle three variables, the Mhz, the cost of a co-processor, and your wallet. Let me explain with an example fro m CAD: My 16 Mhz SX running AutoCAD 386 in its protected mode (32 bit mode) should be able to keep up with AutoCAD 10 running on a 33 Mhz 386 (real mode; 16 bits). The combo of slower Mhz but special modes is a more cost effective solution. Using similar principles, you will have to figure out what is best for you. Image Processing: Depends on the size of the image and # of colours. Generally the faster the better. Designing a cruise missile: You'd need a Cray to do this. You would have to (after you have done the CAD stuff; you aren't anywhere near finished) model compressible fluid flow, probably using finite elements to know things like heat transfer at hypersonic speeds. VERY intensive. Then you might want to model the strutural dynamics of the nose cone on impact, again using the finite element method. I'm NOT saying you can't do engineering with a PC; you most certainly can, but not aerospace; the tolerances demanded in this field presuppose onlyy the most advanced technology to implement it. I hope to use FEA to model airflow past a bike wheel, and eventually a bike frame, which I will be modelling with CAD. For a more down to earth application like this, try to get the fastest machine you can (include the cost of a coprocessor); also look at the access times of the hard-drives in question. CAD programs use the HD alot. Something else I would like to add, if you intend to run UNIX, you will have to look at controller cards, esp if you are using SCSI devices. I have an AHA 1542B. The bus mastering abilities of this host adapter allow it to manage the HD on its own, while the CPU is busy doing something else. The CPU does not have to wait on the HD. You definitely should be aware of things like this if you are going to do multi-tasking, etc. >> At how many MHz does a memory cache become advantageous? >> About 20 Mhz. Many machines at this speed use a 32K cache. Some use 64K. A few 25 Mhz machines use 32K. ALL 33 Mhz machines use a 64K cache. This is because the CPU is too fast for the main memory to keep up. Use of page-mode memory and interleaving can ensure zero-wait-states most of the time at slower speeds. A cache is needed at the upper echelons of the CPU envelope. >> And what else can you do with expansion slots aside from >> memory expansion, video card, drive controller, and (maybe) >> a mouse? >> >Some of the goodies ;-) that you might consider to fill out those empty >expansion slots include: > > 1) Joy sticks > 2) Fax boards > 3) 9 track interface boards > 4) etc.... > >Hope this will help... If would like to discuss these furthure I can be >reached by phone: 415-224-3030 > >Mike Barnes >AT&T Communications Don't forget scanners and a modem... -- "No one had the guts... until now..." -New Anti-Repression Convert (NARC) |-NARCotic $anjay [+] $ingh ssingh@watserv1.[u]waterloo.{edu|cdn}/[ca] -| watserv1%rn alt.CENSORED: UW Provost sez "THINK SAFE THOUGHTS; AVOID NASTY ALT FEEDS; & PROTECT YOURSELF: WEAR A CONDOM ON YOUR HEAD. Call x-2809. Let's Talk.