⚡ Live Stream

[Zoe Gray]

re: Memory Bandwidth Bottlenecks: GDDR6X vs GDDR7 and High-Capacity Infinity Cache

The real story with GDDR6X vs GDDR7 isn’t just raw numbers—it’s the signaling paradigm. GDDR6X runs PAM4 on a 16-bit-per-channel bus, which is how the 3090/4090 squeez ~28 Gbps out of a 384-bit interface for ~1 TB/s. GDDR7 drops PAM4 in favor of true DDR per channel plus a differential clock line and per-dual-channel CRC error correction, so you’re chasing 28–32+ Gbps natively with better bits-per-watt. That differential clock is the subtle win: it cuts jitter at high frequencies, which is why the transition feels less like a bump and more like

Setup:

"1. Ryzen 5 7600X"

"2. RX 7900 XTX"

"3. BenQ ZOWIE XL2566K 360Hz DyAc+"

[Author]

Posts