Couple of links, not directly comparing the two. 3850 AGP and a single core CPU
http://www.tomshardware.com/reviews/ati-agp-3850-agp,1939.htmlOr a brief blurb here:
http://www.tomshardware.com/reviews/graphics-cards,1942-6.html"Forever rumored and now finally available to purchase, the Radeon 3850 is, frankly, a curiously powerful card for the aging AGP bus. In fact, it’s possibly too powerful to be properly utilized on the single-core CPUs that are typically found on this platform.
Regardless, this is the most powerful AGP card you can get. Maybe you have an AGP gaming system you just can’t bear to part with, or perhaps you have an older system with both a dual-core CPU and AGP slot: whatever the reason, you can’t get better than an AGP 3850. If in the future anyone ever releases a more powerful card for the dying bus, we’ll be incredibly surprised."
But other than that, I haven't seen much on the AGP side of that card (in terms of benchmarks). You'll be hard pressed to find one as I'm sure not many reviewing sites would waste their time on that. Not sure how long people want to clutch onto their AGP motherboard...