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Upgrade 101 - Part 3: Adding memoryToronto Star Fast Forward Upgrade 101 series part 3 for Oct. 7/99Preparation and cautions (READ THIS FIRST)
This is the third in our 10-part series on upgrading PCs. In this segment, we're going to add some memory to our test bed. In terms of the actual work of adding a memory module or two, this is a difficulty level 2 task (you have to open the system's case). Tools required: Phillips screwdriver to open the case. Your system manual. Installing is easy; the preparation and shopping is a little harder. How much do you need?Modern graphical operating systems such as Windows and the MacOS want lots of memory just to get themselves on screen. Then they carve up what's left to offer it to the programs you run and they, in turn, will use more. Symptoms of low memory include a slow computer (the operating system keeps swapping code out to your hard drive to make room for more, which slows everything down) and a lot of "illegal operation" errors (the more balls the operating system has in the air, the more likely it is to drop some). The recommended comfortable amount of memory for a Windows 95/98 system is 64 megabytes (MB), but that's the place you start if trying to run Windows NT (soon to be Windows 2000). When you buy a new PC in today's market, you're likely to get between 32 and 128 MB to begin with - and it all depends on the package put together by the vendor. The varied amount allows vendors to offer configurations to fit a range of pocketbooks. Today's memory prices, however, may cause many vendors to offer lower amounts of memory to begin in order not to frighten off potential first-time buyers. So, how come, if what I've said above is accurate, do most applications say on the box that they require less memory than 64 MB? Software vendors, too, are afraid of alienating potential customers. Despite the fact that modern graphical operating systems encourage you to run more than one application at once, the memory amounts specified as minimums on the box assume that you're running only that program. A lot of software products now carry two figures - the absolute minimum you need and the recommended amount required to get the most out of the software - and it's no accident that this figure is often 64 MB. How much is too much?I seldom hear from people who say they have too much memory in their computers, but it can happen under certain conditions. For example, regardless of the age of the computer on which they run, neither Windows 3.1x nor DOS versions less than 7.0 can "see" memory above 64 MB - it simply cannot be used. Windows 95/98, on the other hand can theoretically use up to 4 gigabytes (GB) of memory, although in testing, it stops working with 2 GB or more and may show signs of instability in systems with more than 768 MB (an amount none of us is ever likely to have). However, even relatively recent PCs using Pentium or Pentium MMX processors and Intel's 430VX or 430TX logic chipsets on their motherboards can have problems. These computers have physical room for more than 64 MB of memory. If you add more, they can even use it. However, if you do add more than 64 MB to them, they will slow down by up to 20 per cent. The reason is a little complicated - and the brief description, that the chipsets only allow caching of the first 64 MB isn't much help - but I'll come back to this to clarify it a little later. Note that this does not apply to the 430HX chipset, nor to the 440 series (LX, BX, EX, ZX) for Pentium II/III systems. Shopping tipsThe simple adage that applies when adding memory to your computer: To avoid problems, get more of what you already have. The simplest place to find out what you need is in the manual that should have come with the system. The next simplest way to find out what you already have is to take the system unit with you to a retailer and have the store's technicians look it over. Here are all the things about your PCs memory you have to know before you can shop for more: - its type. Is it FPM-DRAM (fast page mode-dynamic random access memory), EDO RAM (extended data out RAM), or SDRAM (synchronous DRAM). Whether your system can use a specific type will be in the manual, but support for EDO RAM and SDRAM is provided by the motherboard chipset. If the chipset doesn't support a particular type, you cannot use it. And, it's usually not permitted to mix types.
- the number of memory modules you have to add each time you add more, as well as the amount of memory in each module to reach the total you want. New systems using DIMMs add memory one module at a time - and the values can be as high as 128 MB per DIMM. Older Pentium systems using 72-pin SIMMs normally require you to add two modules at a time and computers using 30-pin SIMMs usually require memory to be added four modules at a time. - type of metal used in both the contact strip along the bottom of the module as well as in the memory slots on your motherboard. Once upon a time, both were gold. A few years ago, some companies started using a less-expensive lead / tin alloy. While there is a debate over whether the ion exchange between gold and lead/tin contacts causes corrosion of the lead/tin quickly or slowly, it does occur. You can avoid having to guess which side is right by getting more of what you already have. - whether your system uses parity or non-parity memory. You don't have to know what parity is, but if you get the wrong type of memory, it won't work in your system. If your existing memory modules have nine small chips on the face of each module, it's parity memory and will cost you extra to get more. If they have any other number (such as eight or three), it's non-parity memory and you can breathe a sigh of relief. - anything special about your system's memory. For example, dual inline memory modules may be buffered or unbuffered and use two clock cycles or four. Only your system's manual can tell you for certain. Now, having mentioned the manual several times, I may have led you to believe that it has every answer to every question you'd ever want to know about memory. It should, but sometimes it doesn't. Unfortunately, name brand computer makers often do funny little things to their motherboard designs that require them to put funny memory in them, too. It's just funny enough so you can't buy generic memory for these systems - and their manuals sometimes gloss over the difference. You have to tell your memory vendor exactly which brand and model of computer you have to get an accurate quote. InstallingHow you install memory in your PC depends upon its age. 30- and 72-pin SIMMs work slightly differently than 168-pin DIMMs. See the notes on preparation that dealt with opening the computer case, the precautions to take before you do, and in particular the instructions dealing with taking care of the static electricity in your body.
Once you have the case open, start examining the motherboard surface to find the memory slots. Typically, they're located on the side of the board closest to the drive bays, but they may also be on the side near the front of the computer. There may be as few as two slots or as many as eight. In some systems manufactured during the transition period from 72-pin SIMMs to DIMMs, there may be a mixture of slot types. In some rare cases, you can use both types simultaneously, but it's far more common for you to have to choose one type of memory or the other. Check your manual. If all the slots are empty (because you're starting from scratch), the manual is also the place to find out which slot to start with. It matters. It will also tell you how many modules you need to add each time you add any. 30- and 72-pin SIMMs are held in place from the side, near the top, by small spring clips. The clips may be plastic or metal. If they're plastic, exercise extreme care when attempting to release them because they can break rather easily (ask me how I know). The metal clips are more forgiving. Dump static now.
When you get your new memory home, and before you remove it from the package, dump static again. Examine the modules. A 30-pin SIMM has one edge that is notched slightly (see picture above). When you try to engage it in the memory slot (sliding it in at that same 30-degree angle), it should engage easily. If you have to push hard, stop. You've got it backwards. If you push too hard, you may be able to jam it into the slot in such a way that you'll never get it out. One additional clue will be to examine the other SIMMs that are still mounted in the system to see which side contains the actual DRAM chips. Line the new modules up the same way. 72-pin SIMMs have both a notched end and another notch in the contact strip, just off centre. There's a corresponding off-centre spacer in the memory slot. It's really hard to get these in backwards. As with 30-pin SIMMs, these modules slide into their slots at an angle.
TroubleshootingThere isn't much that can go wrong with new memory that's working, but there are some interesting effects that can pop up. - Your system cannot find the new memory.Most likely cause is that you bought generic memory when your system requires something a little exotic. Did you tell the vendor exactly what brand <italic>and model<italic> of computer you had? Second most likely cause: You have 72-pin SIMMs totalling 32 MB in two 16 MB modules and tried to go to 64 MB by adding a single 32-MB module. Sorry, but I'll bet the farm that your system requires you to add memory two modules at a time. - Himem.SYS reports intermittent parity errorSome readers have told me that some implementations of the Intel 430HX PCIset on early ASUS Pentium motherboards can have problems with some 60ns memory. If you suspect this might be your problem, try resetting the memory speed to 70ns (your on-board setup should allow this). Contact Intel ( www.intel.com ), ASUS ( www.asus.com ), or the vendor of your system's motherboard and the memory module supplier to see if this problem has been addressed. - The system halts or does not boot up. Either the beep codes from the BIOS report parity error (see your manual) or you get an on-screen message to the same effect.There are several possibilities: A memory module has died or is about to do so. A memory slot is malfunctioning. You have parity memory in your system and attempted to add a non-parity module. You have non-parity memory in your system and someone got you to fork out a lot of extra money for a parity memory module. Older memory SIMMs with parity checking on board have nine chips on the surface of each module. If the module has any number other than nine, it is a non-parity SIMM. - The CMOS (see prep notes) reports "memory mismatch"This is normal in some systems where the BIOS doesn't automatically detect the amount of memory in the system and also in systems where it does, but doesn't update the CMOS automatically. Invoke the on-board setup (see prep notes) and call up the screen that reports the amount of memory you have. Even if you don't have to change anything (the BIOS now reports the accurate amount of memory), save the results and exit from setup. Restart the system When more memory is added to a system, or even if a module is removed, then re-inserted, the CMOS, which was running on battery power while the system was off, notes the activity. It invokes the memory mismatch message to alert you to the fact that memory has been changed since the last time the system was powered up. This reset often clears the problem. If saving the CMOS reset doesn't clear up the problem, it's possible that the memory module only appears to be firmly seated in its slot, but in fact is not. Even if you thought you heard the respective clips engage, power the system down, then remove the module and try re-seating it. If this doesn't work, you may have given the module a jolt of static. It may be too badly mismatched in speed with your existing memory to work at all. It may be the wrong type of memory, or may be simply a bad module. In all of these cases, you need to shop for more memory, again - and may want to get the vendor to help you install it this time. What the heck happened to memory prices?If you've been shopping for extra memory for your PC in Metro this season, you'll have noticed that memory prices have been going nuts. Some examples. In the middle of August, PC-100, 32 MB DIMMs (dual inline memory modules) were selling on the street for about $50, 64 MB DIMMs were $100, and 128 MB DIMMs were about $199. As of this week (the week of September 27 - mw), the same DIMMs were $110 for 32 MB, $280 for 64 MB, and a whopping $499 for 128 MB modules. It has an effect not only on people wishing to add memory to existing systems, but it's pushing the price of new computers up as well. The number of theories about the cause depends on who is doing the telling. For example, just about everyone talks about typhoons in Hong Kong and the earthquake in Taiwan. Others note that fall is the traditional time of year for a blip in memory prices as companies stockpile memory in anticipation of the Christmas rush for new computers. Still others point to the new anti-dumping duties imposed by the US Commerce Department against specific Taiwanese companies this past summer. And there are darker theories as well. Taiwan accounts directly for about five per cent of the world's supply of DRAM chips, the main component of memory modules. It also produces components used by other memory manufacturers throughout the world, bringing the total to nearly 12 per cent of the global supply. While it's true that none of the major component fabrication plants were directly damaged by the September quakes, intermittent electricity supply and knocked-out transportation on the island has taken its toll. You simply cannot run a heat-sensitive fabrication process when you have power for 15 minutes, then none for an hour. Not only are the plants incapable of making new components until the situation stabilizes, but all components that were in the manufacturing process when the lights went out have been cooked. As a side-note, Taiwanese factories also supply a significant portion of the global supply of PC motherboards, modems, graphics controllers, sound controllers, and drives of all kinds - as well as supplying board-level components that other manufacturers use to assemble these parts in Japan, Malaysia, Singapore, Indonesia, Korea, Hong Kong, and North America. The short term effect of the resulting part shortfall has made many Metro-area distributors and local system assemblers nervous. Fall is memory manufacturer profit time. Large name-brand companies stockpile systems for back-to-school and Christmas markets. And this year, there's an added bonus. For example, in Canada, the tax break for updating to Y2K-compliant systems runs out at the end of October and there is an anticipation of a mini-boom between now and then. Last spring, led primarily by an initiative from Micron Semiconductor, US memory manufactures complained that it was the dumping practices of Taiwanese companies over the past three years that led to the fall in memory prices from the lofty heights of $50 per megabyte to last summer's low. As a result, the US government slapped duties ranging from 4.96 per cent to 38.9 per cent on Taiwanese memory - specifically altering the amount of the duty depending on the specific supplier. Shortly after the duties came into effect in late June, Micron shut down half of its production capacity for "re-tooling." Then prices for memory imported through the US really began to jump. "The memory market has always been volatile," said Chris Francis, president of Nuvocom, Inc., a local memory importer and distributor. He agreed that it's much like the stock market and subject to the same type of price fluctuations for much the same reasons. When a butterfly sneezes in Taipai, the market can go crazy. When will prices go down? "Not much before January," is the general consensus of local retailers, and it's more likely to last until at least early spring of next year. Have prices stopped rising? We can hope so, but don't bet the ranch on it. Questions? Email troubleshooter@computerwriter.com. Components for this series were provided by Grey-Tech Computers, Inc., Markham, Ont., www.greytech.com. |
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4 - Replacing a graphics controller