Before you can read the parent note on NVLink and GPU interconnects, you must be fluent in a small pile of symbols and units it throws at you without warning. This page builds each one from absolutely nothing, in an order where every idea leans only on the ones before it. If the Hinglish version is easier for you, read the Hinglish note alongside this.
Picture a single wire. Time runs left to right. The wire's voltage bounces between two levels. Each little time-slot holds one bit.
WHAT the figure shows: a voltage-versus-time trace chopped into equal slots, each slot a 1 or a 0.
WHY we need it: every number in the parent note — 20 GT/s, 16 Gb/s, 20 GB/s — is just a way of counting how many of these slots go by per second. Get this picture right and the rest is arithmetic.
Now we count how many bits (or symbols, or bytes) pass a point each second. Each prefix just multiplies by a thousand-ish. We use the clean powers-of-ten convention the parent note uses.
Why three? Because a wire wiggle (a transfer) does not always carry exactly one useful bit. That gap is the next idea.
WHY overhead exists (8b/10b): if you sent a long run of 0s, the wire would sit flat and the receiver's clock would drift — it loses track of where slots begin. So the sender rewrites every 8 real bits as a 10-bit pattern guaranteed to keep wiggling. That is 8b/10b encoding. You pay 2 extra bits for every 8 → you keep a fraction 108.
WHAT the figure shows: a 25 GT/s raw stream funneling through an "8-of-every-10" filter, coming out as 20 Gb/s of payload.
WHY the topic needs it: this is exactly why the datasheet says "25" but the honest bandwidth is "20". The multiply-by-eight-tenths is the whole trick.
WHAT the figure shows: two wires forming one lane, eight lanes stacked into one link, and the arithmetic ladder from GT/s → Gb/s → GB/s → link.
WHY: every headline "20 GB/s" in the parent note is this ladder climbed once. See the ladder once and you never re-derive it in a panic.