ATI Radeon 64MB DDR

Overclocking

While ATI neither recommends nor endorses overclocking (what company does), the possibility of overclocking is found in a third party program: PowerStrip. Used for years, PowerStrip has always provided good support for the overclocker. By implementing support for the Radeon chip in the beta version of PowerStrip, ATI provided an outlet for the true hard-core gamer.

The beta version of PowerStrip that we had enabled for easy overclocking of both the Radeon core as well as its memory clock. Both settings can be adjusted independently, meaning that we were able to push both the core and the memory to the highest amounts that our card would go.

Just how high were we able to get the Radeon to go? Well, as with all .18 micron video card processors, heat was really not an issue when overclocking. Unlike prior .25 micron chips, those based on .18 micron no longer burn when you touch them. As a result of this, chip quality issues are hit long before heat issues.

When overclocking, we were able to get the core of our Radeon 64MB card up to 225 MHz, 40 MHz above the card's shipping speed. Pushing the core any further resulted in not only Quake III Arena crashes but also green text in Windows. The most disappointing thing about raising the core clock was that it resulted in very nominal performance gains, suggesting once again that we had hit a memory bus bandwidth limitation.

As suspected, performance jumped significantly when the 183 MHz DDR memory was pushed higher. Rated at 5.5 ns, the RAM was running at its speced speed, however, as in the past, we were able to push the Hyundai SDRAM chips even further. With PowerStrip pushing up the memory clock speed, we were able to get the DDR SDRAM chips up to 205 MHz DDR for an effective memory clock speed of 410 MHz. At this speed were were finally able to see the true power of the Radeon's core, as performance kept increasing as the memory clock was pushed higher and higher. Unfortunately, at speeds above 205 MHz, snow artifacts began to surface in Quake III Arena runs.

What the tests showed was that once again memory bandwidth is the limit in today's high end video accelerators. Luckily, with the core speed up to 225 MHz and the memory running at 205 MHz DDR, we had an even more powerful card on our hands. Let's take a look and see how it performed.