We did try to overclock our Radeon 3850 AGP to see if we could squeeze any extra performance out of it. We were quite keen to demonstrate if the AGP 3850 could keep up with its 3870 cousin at identical clock speeds, to further examine if the AGP bus was causing any slowdowns (even though most of our benchmarks show that this is not the case).
Unfortunately, ATI’s Overdrive utility was completely uncooperative in this respect. Even though it was happy to change the clock speeds of the PCI Express version of the Radeon 3870, the drivers would not work on the AGP version of the card.
With no other working overclocking tools — we mentioned earlier in the review that we couldn’t get ATItool or ATI tray tools to work — we were unable to test this aspect of the card’s performance. Indeed, it looks as though this functionality isn’t supported in Vista at this time.
We also wanted to overclock the Athlon 3400+ CPU to see if we could up the ante and remove some of the CPU bottleneck, but we were once again foiled. To get the system running with 2 GB of memory, we had to use a Frankenstein mishmash of old DDR RAM that wasn’t particularly happy to accommodate any overclocking efforts. And to get any speed out of the CPU we had to slow down the RAM, which doesn’t tell us much, so we’ll have to wait until Part 2 of this review to see if a CPU change will significantly move the bottleneck. We should be able to secure some faster and more cooperative DDR memory by then as well, and we’ll be able to compare single and dual core CPU overclocking.