I have a 486SX 33Mhz with 4MB of RAM. How can I update this machine to increase its performance? Should I get more RAM or an overdrive processor?

According to Family PC Magazine, which is a Ziff-Davis company (publisher of almost all the major computer magazines), the most cost-effective upgrade you can perform on a Windows system is to go from 4MB to 8MB of memory. Their testing labs determined that memory turns out to be the critical bottleneck in a Windows system. Upgrading to 8MB of RAM nearly doubles your system's performance. What does it cost? In a mail-order catalog I received today, a 4MB SIMM (single inline memory module) costs about $150 for either 30-pin or 72-pin types. Your computer's owner's manual will tell you which kind you need.

On the other hand, performance scores for CPU upgrades were the most surprising -- and disappointing -- results discovered in their testing. They determined that unless you have at least 8MB of RAM, the CPU upgrade doesn't do you a lot of good. With only 4MB of RAM, doubling the processor speed with a DX2 resulted in barely a 10% increase in performance, and tripling the processor speed with a DX4 yielded only a 20% increase - not the 100% or 200% increases you'd expect. Even more surprising, a Pentium OverDrive did no better than the DX4.

However, when the system has 8MB of RAM, the results of upgrading the CPU are what you'd expect from doubling the speed of your processor - in fact, the speed of their test system jumped to nearly 2.3 times that of the base system with both an increase to 8MB and a DX2 CPU upgrade. The DX4 still didn't triple the system speed, though, and the Pentium did little better than the DX4. Still, you'll probably want to upgrade both parts of your system at some point. But the RAM upgrade should definitely be first.

Other system enhancements tested by Family PC were cache upgrades (high-speed memory that sits between your CPU and RAM), hard drive and CD-ROM drive upgrades, and video adapter upgrades. As with other CPU upgrades, they were disappointed with the cache upgrade. And, though they don't strictly qualify as performance upgrades, adding new expansion devices such as a faster hard drive or CD-ROM drive can enhance overall system performance. A new video adapter won't speed up your system, but it will allow you to see more colors with higher resolution. In the final analysis, however, the overwhelming winner in the bang-for-the-buck category was still a RAM upgrade.

I also have a 33 MHz 486SX, but I already have 8MB of RAM. Last week I ordered a DX4 clock-tripler that will take my system to 100 MHz and add a math coprocessor for $140 from an Internet-based discounter. A math coprocessor is an auxiliary chip developed to work in conjunction with the main processor providing more precise computational power. Although traditionally only engineering and scientific applications have benefited from having a math coprocessor, today's high-end graphics programs are making use of math coprocessors to allow elaborate special visual effects. Since I regularly use these programs, having a coprocessor chip is perhaps more important to me than to the average user. But this upgrade chip seemed to offer a lot of improvement for a reasonable amount of money.

To install the DX4, I opened up my computer by removing the case. I located the rather large, square 486SX chip on the main circuit board, or motherboard, of my computer and very carefully removed it with a tool supplied with the upgrade chip. Then I simply inserted the new chip and firmly pressed it down into the empty socket. One corner of the original 486 chip has the point flattened, indicating the location of connecting pin #1. Care must be taken to insert the new chip with its pin #1 in the same position, or damage could result to the new processor or to the motherboard. I also had to inform my motherboard of the presence of the higher-powered processor by reconfiguring some small jumper wires over small pins according to a diagram in the user's manual that came with my motherboard. Once this was done, I replaced the case and turned on my computer.

The messages that flash on the screen when a computer first starts up, or boots, now reflected the fact that a math coprocessor was present. When Windows 95 finally appeared, I was hoping its formerly sluggish performance would be significantly faster. Well, it's faster, but not by as much as I had hoped. In fact, from running a performance measurement, or benchmark, program supplied with the processor upgrade before and after its installation, the indications are that the performance increase is only about 16%, which is in line with Family PC's findings of about a 20% performance increase from a clock-tripler upgrade while keeping the amount of memory the same.

The good news, however, is that all the features of my graphics programs that require a math coprocessor to work now perform like a charm. In addition to graphics programs, some add-in programs that allow you to hear sounds or view 3D pictures over the Internet require a certain degree of processor horsepower that my old 486SX couldn't provide. All the ones I've tried so far finally work like they're supposed to with the new 100MHz processor.

The bottom line is: since I use programs that make use of a math coprocessor, this upgrade, although not as fast as I had hoped, does result in some speed increase and allows me to take full advantage of my graphics programs, so I'd have to say it's worth it to me. And, when I ultimately upgrade my memory to 16MB, I'll have the drastic performance boost I'm looking for.

But is a 16% performance increase worth $140 or more to the average non-graphics user? I guess you'll have to answer that one for yourselves.

K.O.P.C.Online home > table of contents > upgrade