The world of technology never ceases to amaze us, and today we are thrilled to delve into the remarkable advancements brought about by PCIe 6.0, specifically focusing on the intriguing concept of “FLIT” – the Flow Control unit.
With the lightning-fast data rates doubling in PCIe 6.0 compared to its predecessor, maintaining optimal power consumption while scaling up data rates became a challenge. To address this, PCIe 6.0 retains the same channel length as gen 5.0 while embracing “PAM4 signaling,” utilizing four voltage levels. This power-efficient technique, while revolutionary, introduces a heightened susceptibility to errors, leading to an increase in Bit Error Rate (BER).
Forward Error Correction (FEC), a technology designed to combat single-bit errors and enhance data reliability. And here’s where FLIT makes its grand entrance. To effectively implement FEC and manage errors, a fixed-size packet is needed – thus, the birth of FLIT in PCIe 6.0.
“What’s Inside a FLIT?”
So, what’s packed within this intriguing FLIT unit? Currently, we’re utilizing a 256-byte FLIT, encompassing 6 bytes of FEC, 8 bytes of CRC, 6 bytes of DLP, and a whopping 236 bytes of TLP.
“Why 256 Bytes?”
While there are various supported FLIT sizes, such as 740 bytes and 64 bytes, the magic of 256 bytes lies in its ability to strike a harmonious balance between efficiency and latency. Some sizes optimize efficiency at the cost of higher latency, while others offer lower latency with moderate efficiency. The 256-byte FLIT stands as the gold standard, beautifully aligning both latency and efficiency, making it the go-to choice for PCIe 6.0.
The Ultimate Impact
As the spectrum of applications demanding higher bandwidth and top-notch performance continues to broaden, the role of FLIT in PCIe 6.0 becomes even more significant. By reducing latency while supercharging performance, FLIT transforms PCIe into a common connection for an array of real-time applications.
The future is unfolding before our eyes, and the innovative strides taken by technologies like FLIT in PCIe 6.0 are reshaping the landscape of connectivity and performance.