Robert L. Hummel
Intel's latest OverDrive processor boosts your system's business applications performance while adding support for multimedia extensions (MMX) technology. However, if you're on a tight budget, you should investigate less expensive memory upgrades first.
Intel (800-538-3373 or 503-264-7000;
http://www.intel.com/procs/overdrive
) offers several versions of its Pentium OverDrive processor with
MMX technology for upgrading older Pentium systems. An upgrade from 75 to 125 MHz or from 90 to 150 MHz costs $399. The upgrade from 100 to 166 MHz costs $499.
The OverDrive with MMX incorporates leading-edge Intel technology, such as 0.35-micron fabrication and 2.8-V operation. Both techniques allow Intel to produce faster processors that consume less power and produce less heat. So it can work in older 3.3-V systems, the OverDrive with MMX provides its own voltage converter, filters, and a fail-safe protection system.
All this intelligence fits on a tiny piggyback circuit board hidden inside the heat sink under the integrated fan. To ensure an adequate supply of instructions and data to feed the OverDrive's core, the OverDrive's on-chip cache is 32 KB, which is twice that of a non-MMX Pentium processor.
Is this OverDrive upgrade worth the price compared to a less expensive memory upgrade? Based on tests BYTE ran using the application-based SYSmark/32 suite of benchmarks from Business Applications Performance Group (BAPCo,
http://www.bapco.com
), many users will have trouble justifying the expense, given the modest performance increase.
BYTE tested a Dell 90-MHz Pentium system upgraded to a 150-MHz Pentium OverDrive with MMX. The upgrade went smoothly, though that may not always be the case (see this month's Bug of the Month). To gauge business applications performance improvement, we used SYSmark/32 under Windows 95 to evaluate the system before and after the upgrade.
To determine cost-effectiveness, we also compared the OverDrive's increase to a much cheaper upgrade: adding RAM. Plugging the OverDrive with MMX into our 16-MB system increased the SYSmark/32 score by 34 percent (
see the chart
). Leaving the original 90-MHz processor installed and increasing system RAM from 16 to 32 MB produced only half that increase. But at one-sixth the $399 price of the 150-MHz OverDrive, the 16-MB RAM upgrade (which cost abo
ut $65) represents a better upgrade value.
However, adding memory goes only so far. If your system already has 32 MB of RAM, BYTE found that doubling it to 64 MB makes little difference in the SYSmark/32 scores. Some of the individual application scores actually decrease slightly! The highest performance increase comes from adding the OverDrive and 16 MB of RAM (for a total of 32 MB), which produces an increase of 70 percent compared to the baseline 90-MHz system with 16 MB.
What's the best choice? If your system is limping along with just 16 MB of RAM, spend the $65 to upgrade it to 32 MB and wait for OverDrive prices to drop. However, if you're attached to your current system and need that extra boost and those MMX instructions now, the OverDrive MMX will increase your throughput modestly while lightening your wallet substantially.
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Upgrading to 32 MB of RAM delivered half the boost of an OverDrive, but at one-sixth the price.
MMX OverDrive = Expensive Upgrade
