I've just spent ~1 hour trying to find the page from my history and I honestly couldn't find it. I also google'd for it for about another hour and still couldn't find it within the search results. If I find the source later I will remember to post it here. The blog was a bit speculative but it used some logic to explain why the Tegra 2 should perform slightly better than the Hummingbird when it comes to graphics, but if given the actual requirements for the chips the "theoretical" performance of the SGX540 was noticeably higher.

You can take this as a grain of salt, personally I think its accurate, but none of these matters when the OEM provides shoddy drivers/sloppy software (like in the case of Galaxy S and the homebrew lag fix).

Also, I think it's going to be hard to find the practical pixel throughput for the devices/chips on the internet because that's specific information. You may have to wait to buy them and benchmark them yourself ... i know it sucks, but thats the case until there are enough Tegra2 devices and benchmarking tools out there.