Jitter significantly limits the maximum achievable data rates (MADR) over high-speed source-synchronous I/O links. In this paper, we present a simple model that comprehends transmitter and receiver jitter in a source-synchronous I/O link. We show that the channel can have a significant impact on transmit jitter at high data rates, resulting in 1.1X-3.8X jitter amplification for typical cases. We quantify the performance degradation of transmit/receive equalization and multi-level modulation schemes, due to jitter in high-speed I/O links. We present two design techniques to mitigate the effect of jitter on performance - transmission of a slower source-synchronous clock, and jitter equalization. Both techniques can improve MADR by 13% when signaling over a 20" FR4 channel.