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Upgrade It

You've run Wintune on your system and compared the results with those of other systems in its class. You've tried all the tuneup tips we describe in this issue, as well as those recommended to you by Wintune. In short, you gave it your best shot, but you're still not happy with your PC's performance.

There's one last step to take before you bite the bullet and purchase a whole new system.

A well-considered upgrade just might give your setup the extra vim and vigor you're looking for. The four articles in this section tell you what you need to know about upgrading your CPU, memory, hard disk and video. When is it worth investing a few more bucks in your old system? Which components does it make the most sense to upgrade? Read on.

Upgrade It: CPU

A CPU upgrade isn't always the best path to greater power. When is it right for your system?

By Jonathan Blackwood
Reviews Editor, Hardware

Carbon-based life forms like us have a significant advantage over the silicon kind: We don't become obsolete nearly as quickly. That's how you can console yourself when you discover the computer you bought two years ago for $2,500 is already wheezing. And that 286 you have at home is positively Precambrian. Of course, if a system is still useful to you, it's not obsolete. Hang onto that 286 or 386 if you're using it only for word processing, Quicken for DOS or downloading files. If you want more power, trade up and donate the old dinosaur to a friend. Although there are CPU upgrades for these machines (such as the Make-It 486 package from Improve Technologies), you probably don't want to trust your data to a five-year-old, 40MB MFM hard drive-not to mention the antiquated BIOSes in machines of that era. Let 'em move gracefully toward extinction.

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Can You Upgrade?

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Can You Upgrade?

The upgrade outlook is more optimistic if you have a 486 or Pentium machine. CPU upgrades are currently available for both, and you should be able to get OverDrive upgrades for Pentium Pros later this year.

If you have a 486 that runs on a 25MHz or 33MHz motherboard, you can get a clock-doubled or -tripled CPU upgrade from Intel, Evergreen Technologies, Gainberry Computer or Kingston Technology. Naturally, the Intel OverDrive modules use Intel processors, while the other vendors use chips from AMD, Cyrix or Texas Instruments. These lower-priced chips are functionally similar and provide performance levels comparable to the Intel models.

CPU upgrades are not for every machine. Don't consider upgrading the CPU on a 486 without local bus graphics.

A system board with local bus graphics allows the video subsystem to run at the full speed of the motherboard-typically 25MHz or 33MHz for 486 systems-on a 32-bit (or even higher bandwidth) pathway. Nonlocal bus models push the video subsystem's data stream through the ISA bus, where it finds a 16-bit, 8MHz bottleneck. And local bus technology-there are two varieties, VESA (Video Electronics Standards Association) and PCI (Peripheral Component Interconnect)-must be engineered into the system board from the start. You can't graft it on later with a standard ISA card. So the only way to add local bus to an existing system is to replace the motherboard. More about that later.

Running Windows 95 on a 486 without local bus technology is too painful to contemplate. For that matter, even running Microsoft Word 6.0 and Windows 3.1x on such a system is a dreadful prospect.

Upgrading the CPU of a DX4-75 or DX4-100 486 machine is pointless as well. The DX4-75 is already a clock-tripled chip running on a 25MHz motherboard, and the DX4-100 is a clock-tripled chip running on a 33MHz motherboard. You could pop in a Pentium OverDrive processor, but you wouldn't even notice the performance increase.

In fact, in terms of cost or performance, the Pentium OverDrive for 486 Systems isn't a particularly good solution for most 486 computers. Many machines--including a number of Gateway 2000 486DX2/66 systems from 1993, for instance--simply won't boot with the Pentium OverDrive. This is because some system board manufacturers built boards to accommodate the Pentium OverDrive chip before Intel finalized the specifications.

If your system is a good candidate for the Pentium OverDrive (one that's on Intel's approved list), make sure it has write-back caching, which writes data directly to level 1 cache, rather than first to system RAM. Without it, you'd do better with a 486DX4-100 OverDrive chip.

You have to consider other issues, too, such as whether your CPU socket is of the 3.3-volt or the 5-volt variety, and whether your replacement CPU will match the available voltage or will require a voltage regulator adapter. You'll probably find a booklet at the point of sale that will tell you which chips are candidates for your machine. Whatever you do, before you purchase a CPU upgrade--or a new hard disk or video card, for that matter--make sure you can return it if you can't use it.

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Even if your machine is a good candidate for a CPU upgrade, be aware that overall system performance is governed by much more than the CPU. A slow or compressed hard disk, the lack of a level 2 cache or a slow video card can put a serious drag on your system's performance. And the easiest, quickest path to better performance on a Windows system is upgrading to 16MB of RAM. So when you're thinking about a processor upgrade, consider the benefits versus the cost of upgrading these other system components.

All things considered, the most you should expect when you double your processor speed-say, from 33MHz to 66MHz-is about a 70 percent performance improvement. Although noticeable, it won't change your life, and most applications will improve by only 30 to 40 percent. Tripling that same 33MHz processor to a 100MHz DX4 would be worthwhile. You could expect a performance increase of roughly 150 percent, or about 2.5 times the original.

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Upgrade the Motherboard

Suppose you have an aging 486, and you need more performance than a DX4-100 OverDrive chip will provide. If your machine is a relatively generic clone in a Baby AT or tower case, replacing the motherboard may be a good idea. Pentium motherboards are available through mail order or at retail shops like Computer City. You can either order the motherboard alone or you can get a motherboard with the Pentium chip already installed. Plan on spending around $500 for the new system board with a 100MHz Pentium chip.

Installing your new motherboard requires major computer surgery, so don't reach for that scalpel unless you're happy with your system's other components, such as the hard drive. You should also consider the amount and type of RAM you have. The 30-pin SIMMs from your old system, for instance, won't fit into the 72-pin SIMM slots on newer motherboards. (There's one potential "gotcha" here: Pentium systems can't make use of 16MB SIMMs. So if the RAM configuration in your existing 486 system consists of one 16MB, 72-pin SIMM, plan on swapping it out at the going exchange rate.) You can either buy a motherboard that accepts both types of SIMMs, or you can sell your existing RAM to a mail order house for about $20 per megabyte and buy new RAM for around $45 per megabyte.

Let's say you have a 1993 Gateway 2000 486DX2/66 machine with VESA local bus. You can replace its system board with a new Pentium motherboard with the Triton chipset and get 256KB of level 2 cache, a 100MHz Pentium chip and a new PCI video board. However, the Gateway 2000 already uses 72-pin SIMMs, so you don't have to worry about trading in old SIMMs. You now have a perfectly functional, much faster machine at a cost of a little more than $600.

You should probably do something about that 340MB hard drive. About $200 will buy you a new 1GB drive. Another $150 will purchase a new quad-speed IDE CD-ROM drive. Now you've plunked down roughly $1,000. Of course, a brand new 100MHz Pentium system will set you back around $2,000, but it will also spare you the hassle of reconfiguring your old machine. It's your pocketbook and your call.

If you already have a Pentium, Intel's new Pentium OverDrive for Pentium Systems is a fast, easy and effective means of upgrading your system. The new chips also use clock-doubling technology, and are pin- and BIOS-compatible with existing motherboards. Pop out the old chip, put in the new one and you're off to the races at a significantly faster clip, with none of the compatibility problems that existed with the Pentium OverDrive for 486 Systems. You can upgrade a Pentium 66 to a Pentium 133, for instance, or you can purchase a 100MHz Pentium system and plan to upgrade it to a 166MHz model later. All you'll need to do is simply replace the chip.

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Upgrades at a Glance

If any of these describes your PC, a CPU upgrade is either impossible or not worth it. Consider buying a whole new system.

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Power Dial

Here are a few vendors to call when you're ready to upgrade your CPU.

800-538-3373, 408-765-8080.

Evergreen Technologies
541-757-0934, fax 541-757-7350.

Gainberry Computer
800-825-7331, 905-415-0480.

Improve Technologies

Kingston Technology
800-337-8410, 714-435-2600.

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