A PC buyer's primer.
A PC is not everything to everyone. You must know whether your PC will be used to type five letters a week or model 20,000 biochemical reactions a day.
* Wrong item, wrong price. I estimate that most organizations waste more than 10% of staff time and 50% of hardware and software purchases because they buy the wrong items at the wrong prices and fail to teach staff how to use them. In other words, they don't know the most effective program for a particular application. I know one department director who pays a person with no computer experience between $12 and $15 an hour to write tables and do simple graphs fro scratch. That misguided manager may spend several hundred dollars and waste several days doing what would take 5 minutes and cost $1 using the right software.
* More than a toy. Computers now come in far more models than ever and have a wide range of options designed for specific tasks. Before you buy a computer, you must consider your immediate needs and likely usage over the next 3 years. Be realistic. A computer in your office is more than an appliance or a toy: It is an integral part of your job and your life.
Once you start using a computer, you are tied to it every time you turn it on. You must learn commands, file names, daily maintenance, and other chores. If yo are not ready to learn all it takes, limit your purchase to what you can handle A computer requires 100% accuracy on your part. Contrary to popular belief, an inexperienced user can destroy quite a bit of information. Before you risk wiping out a year's worth of data, take the time to study the basics. See "Common computer terms," p. 55, and my earlier Computer Dialog columns for information on networks, computers connected to laboratory equipment, and futur computer needs in the [lab.sup.1-3] What follows are some PC buying and operating tips for laboratorians who are not already computer experts.
* Speed demons. Computers work in cycles of time as measured in megahertz (Mhz, 1 million cycles per second). The electronics that connect all parts are called buses and are limited to about 16 to 32 Mhz. Central processing units (CPUs) can go from 10 to 100 Mhz. To move information faster to the screen or hard disk, manufacturers have implemented a faster bus called a local channel that bypasses the CPU. There are two versions: the 1992-1993 version, VESA, and the 1993-1995 model, PCI. If you think you need that much speed, VESA will add about $50 to the cost of a computer; PCI will add another $100.
Computers using more powerful CPUs are built with more powerful components and faster random access memory (RAM). The higher the number of cycles, the faster the CPU. For PCs made with 80386 chips, 16, 20, 25, 33, and 40 Mhz are the most common processing speeds. With 80486 PCs, 25, 33, X2 (double the speed), and X4 (triple the speed) are found most often. With newer Pentium (Intel Corp., Portland, Ore.) CPUs, 60 and 100 Mhz are typical.
* Original or clone? Initially, most CPUs were made by Intel, which has or ha the copyrights and patents on them. Many companies acquired partial rights or developed a functionally equivalent clone based on different structures. There are now four major manufacturers: Intel; IBM (International Business Machines, Armonk, N.Y.), which has rights to Intel products if sold as part of the computer; AMD (Sunnyvale, Calif.); and Cyrix (Richardson, Tex.). Because non-Intel processors are usually cheaper and faster, a 386/40 Mhz CPU from AMD may cost less and outperform a 386/33 Mhz from Intel. Several new companies may clone the Pentium.
* Special features. There are several types of CPUs. In general, the 386 and S models do not contain mathematics coprocessors, while the 486DX and Pentium do. The coprocessor accelerates calculations used for statistical analyses and graphics drawing. Some processors include the designation "L." These CPUs are designed to use small amounts of electricity and are found in portable PCs.
Typical hard drives range in storage capacity from 80 to 400 Mb. Larger ones that can hold the huge databases found in clinical laboratories are available but are far more expensive. Monitors vary in screen size and resolution. Most medical and text applications, which do not need high quality professional graphics and design applications, do fine with cheaper and smaller monitors. With rare exceptions, most components are excellent and it is seldom beneficial to pay extra for a well-known brand name. In fact, a local assembler in your area may provide better and more cost-effective service (and probably uses the same parts as better-known companies).
* Typical uses. Typing and preparing documents are best done with word processors. Calculating data for tables is best done with either spreadsheets o statistical analysis software. The storage and retrieval of information may be done with:
* Word processors (for random thoughts and small text files)
* Spreadsheets (for well-organized and relatively small data sets)
* Databases (with different ones used for specific tasks)
Special software and modems handle communications with other computers, fax, an voice and electronic mail. There are a wide range of graphics programs for charts, drawings, and presentations that use multimedia. Each of these programs can be adapted to the specific needs of the individual, and each has different hardware needs.
There are single programs that do almost everything. Modern word processors include graphics and table-making features, for example. But you may spend hour or days doing a task that a more specific program can do in minutes. If you do certain tasks frequently (such as graphics, QC charts, or presentations), you will save more in personnel time than you will spend in a one-time purchase of appropriate software. I collect data using general-purpose, data-acquisition software. I then transfer the data to a spreadsheet to do the appropriate calculations. I analyze the data with a statistical program.
You can buy a PC at prices ranging from $200 to nearly $20,000. More money will buy faster, more efficient, and easier-to-use equipment. It will also get you additional accessories and devices that may be of some use to you. On the other hand, you don't really need a Porsche to drive to the corner.
* Opening Windows. One significant decision you must make is whether you want a computer that will run Windows (Microsoft Corp., Redmond, Wash.), the graphic operating system that makes your PC look like an Apple computer, or if you are sticking with DOS (Microsoft). Every non-Apple PC needs DOS to run and manage all other programs. Software running under DOS is very fast and efficient. It also can operate on cheaper computers and requires fewer resources. However, most DOS programs have very different and unique interfaces (appearances), and you must learn each one. It often takes more time to learn a DOS program than i does to master one under Windows.
Windows superimposes upon DOS another interface, one that is standard across programs and easier to use. Because of this intermediary, programs run more slowly and require faster and more expensive computers to run well. Most companies are writing Windows-only software because it more easily interacts with already existing programs. For these reasons (and because Windows programs make it easier to communicate with input and output devices), most lab software is being written only for Windows.
Programs running under Windows can easily exchange information--tables, drawings, voices, pictures, and data, for example--and can receive or send data through many devices. By 1995, the difference between Windows and DOS will ceas to exist. The impending version 4.0 update of Windows practically eliminates DOS. If you are planning to buy a computer near the end of this year, it might benefit you to wait to purchase one with Windows 4.0. In general, the cost of a faster computer using Windows is recovered in saved staff time. If you do not need the power of large computer programs, however, but are sticking with such specialized application as answering the phone or typing letters, you can get a "obsolete" 386 PC for under $700. The periodical Computer Shopper, found at man newsstands, will prove a good resource.
Another important decision you must make is whether you need to share data or software among different computers. If you do, you must set up a network. Such system requires a server--a fast central computer that coordinates the PCs in the network. It costs about $300 to connect a PC to a network.
* Buy what you need. Most individuals use PCs mainly for word processing, occasionally opening a spreadsheet. DOS-based word processors, spreadsheets, an a large variety of other kinds of software will run well on an old 80286 PC wit 2 Mb RAM and a 40 to 80 Mb hard drive (available for under $400). These sometimes come with EGA or VGA color monitors.
* More sophisticated word processors demand more memory and speed. A 386SX, 1 Mhz unit with a VGA monitor, 60 to 80 Mb hard drive, and 2 Mb RAM (available fo about $600) is an excellent system for DOS programs. It will serve for Windows applications but only if you use such features rarely (they run slowly on a 386). I used a 386 for several years for my lab.
The next minimum system adequate for simple Windows applications is a 386/25 Mh or a 486SX/40 Mhz. These systems sell for about $1,000 (with a 140 Mb hard disk and 4 Mb RAM). If you choose to standardize on Windows, which I recommend for most laboratories, then this is the minimum basic system for administrative an secretarial staff. It will not be enough to run Windows 4.0, however.
* Faster and faster. For those who also use word processing to prepare tables and simple graphics, or for frequent recalculations on spreadsheets of small size (under 200 Kb), you should choose a computer with a mathematics coprocessor. For a small additional cost, I recommend a 486DX2/50 or 66 Mhz system with a VESA local bus for such Windows-intensive applications as large calculations on spreadsheets, statistics, pattern recognition, plots, and complex graphics. You can buy a 486DX2/66 Mhz system with 4 Mb RAM and a 200 Kb hard drive for under $1,200. (Get 8 Mb if you can.)
The price of these computers makes them cost-effective. Competition among CPU makers and the availability of the Pentium is driving prices down. The boost in performance that you get with a Pentium does not justify its far greater 1994 price unless you have a specific need for it. Were you to purchase a smaller computer and attempt to upgrade, however, the cost would be much higher. Upgrading to a faster processor with the intention of plugging it into your old computer usually is not cost-effective. When you buy the processor as an individual unit, you pay a premium. If you then upgrade the memory and other parts needed to take advantage of the faster processor, it may cost you almost as much as an entire new computer (unless your current model is loaded with man accessories).
A local bus allows the video card, and sometimes the disk controller card, to operate at speeds close to that of the processor. This means 33 Mhz or more (while the current bus or motherboard operates at 8 to 16 Mhz). In addition, video cards designed for Windows can display data 5 to 20 times faster than regular video cards. Using Windows, a fast local bus computer and a fast video card may give you improvements of more than 20 times the speed of an old 386/16 Mhz computer.
* Upgrading memory. RAM is sold in units of 256 Kb and 1, 4, 16, and 64 Mb (units increase by a factor of four). Most computers have four slots for memory on the board. If you purchase 4 Mb, you usually buy four 1 Mb chips. When you want to upgrade, you discard the 1 Mb chips and buy new, bigger ones.
Plan ahead for your needs because memory prices drop every year. If you anticipate needing more memory within 6 to 12 months, save money and time and buy it now. For instrument control, 2 Mb is often enough. For mathematical calculations involving area integration (such as used in chromatography), pattern recognition (hematology, for example), or statistics on large files, yo may need from 8 to 16 Mb RAM. It may be much cheaper to buy one 16 Mb chip now, rather than getting two 4 Mb chips when you purchase your computer and having t buy another two later on.
If you run several Windows applications that use graphics (such as those used t prepare slides for presentations) or very large files (over 5 Mb), you should have at least 8 Mb and, preferably, 16 Mb RAM. Otherwise, every time you change something in your graphic, it will take a long time to redraw. I find that slow computers cost more in staff time than you would spend on more expensive and faster PCs.
1. Siguel EN. How to make a fortune by marketing good laboratory computers. Computer Dialog. MLO. May 1991; 23(5): 75-77.
2. Siguel EN. The future of computer-aided diagnosis in the laboratory. Compute Dialog. MLO. August 1991; 23(8): 71-73.
3. Siguel EN. Casting your net for optimal networking. Computer Dialog. MLO. February 1992; 24(2): 51-53.
Common computer terms
* Motherboard: The electronic module that holds the basic computer parts.
* Case: The housing for the motherboard and other components, commonly including video, modem, and fax cards, or hard, floppy, and CD ROM drives. The case can be either horizontal or vertical.
* Central processing unit (CPU): Included in the motherboard, the CPU is the core of the entire computer system. For PCs, CPUs come in sizes of increasing power: 80286, 80386, 80486, and 80586 (Pentium).
* Random access memory (RAM): The memory used by the computer to temporarily store programs and data and quickly execute them. RAM comes in chips of 256 Kb, 1 Mb, 4 Mb, and 16 Mb.
* Hard disk/drive: The component used to permanently store data and programs within the case. Hard disks come in many different speeds and capacities.
* Floppy disks: Storage devices for holding your data outside the case. They come in sizes of 3.5 inches (720 Kb or 1.44 Mb capacity) and 5.25 inches (360 K or 1.2 Mb capacity).
* Removable media: Large-capacity (usually 40-600 Mb) storage devices. They may be removable hard drives or optical laser disks.
Edward N. Siguel is a senior scientist in the Fatty Acid Laboratory, Clinical Nutrition Unit, Boston University Medical Center Hospital, Boston.
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|Title Annotation:||includes related article; part 1|
|Author:||Siguel, Edward N.|
|Publication:||Medical Laboratory Observer|
|Date:||Sep 1, 1994|
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