The limit of ADC is the single-link DVI resolution of 1920x1200.
Power isn't the limit, Apple had a 17" CRT that ran off ADC. (By the way, the power isn't being supplied over the PCI (or AGP) bus, it's by an extra set of power pins that ADC-compatible video cards have. These extra power pins are dedicated solely to powering the monitor. Why they didn't just adopt the already existing standard of "AGP Pro" is beyond me, though; since all AGP Pro over standard AGP added was extra power.) A 17" CRT uses a lot more power than even the 23" LCD does. (113W vs. 90W.) Although, oddly, Wikipedia claims that ADC tops out at 100W. Which would be an issue since the 17" ADC CRT draws 113W.
ADC also carried the analog pins of DVI-I, which is how the CRT Studio Displays ran. They were not digital (which is why some later ADC video cards can't run the CRTs; they don't pass through the analog signal,) but analog, basically VGA. In fact, the CRT studio displays can run at higher resolution than 1920x1200; but you have to force it; as it's not available by default.
Power isn't the limit, Apple had a 17" CRT that ran off ADC. (By the way, the power isn't being supplied over the PCI (or AGP) bus, it's by an extra set of power pins that ADC-compatible video cards have. These extra power pins are dedicated solely to powering the monitor. Why they didn't just adopt the already existing standard of "AGP Pro" is beyond me, though; since all AGP Pro over standard AGP added was extra power.) A 17" CRT uses a lot more power than even the 23" LCD does. (113W vs. 90W.) Although, oddly, Wikipedia claims that ADC tops out at 100W. Which would be an issue since the 17" ADC CRT draws 113W.
ADC also carried the analog pins of DVI-I, which is how the CRT Studio Displays ran. They were not digital (which is why some later ADC video cards can't run the CRTs; they don't pass through the analog signal,) but analog, basically VGA. In fact, the CRT studio displays can run at higher resolution than 1920x1200; but you have to force it; as it's not available by default.