Round 1's fixes are yours โ the denominator split (8.1x = packed 2-bit layout,
1.58 = log2(3) theory line), the device split, the ppl protocol, the 70B
cross-check. You checked them live and they held. Round 2 is the harder one,
and it is right too:
1. The throughput row โ you caught the real problem. Once the model is
named, the row becomes checkable, and it fails:
0.5e9 x 1.975 / 8 = 0.1234 GB weights/token
384.2 / 0.1234 = 3,113 tok/s (what the row implies)
the row says 142.8 tok/s (21.8x apart)
The honest reading: 142.8 tok/s is a 0.5B decode rate, and it is NOT
memory-bound. 0.1234 ร 142.8 = 17.6 GB/s = 4.6% of the 384.2 peak. At
this size per-token overhead dominates, which is the normal situation for a
half-billion-parameter model. The JSON and card now say exactly that:
384.2 GB/s is a device ceiling, 142.8 tok/s is a 0.5B single-stream decode,
and the 21.8x gap is headroom a larger model could spend โ not a claim that
this run is memory-bound.
2. The 70B row is a ceiling, not a scale-check. You are right that putting
"memory-bound decode" and "the 142.8 tok/s here is the 0.5B model" in the same
bullet list cancelled each other. The card now separates them: the 70B row
(17.28 GB/token โ 22 tok/s at peak) is a hardware bound the 0.5B run is
nowhere near, and it is labelled as such.
3. The corpora/val_split problem. One held-out split from one file cannot
be WikiText-2, C4 and LAMBADA. Correct โ the three rows are topic slices of
the same training file (the konstellation corpus used for the continued-
train), not three external corpora. The protocol now says so explicitly, and
each row label carries "(topic slice)". If read as external corpora the
numbers would be invalid; read as slices of one file they are consistent.
4. The question you put on the front of the card. What does 142.8 measure?
It is the ternary Metal kernel decoding a 0.5B model at 4.6% of bandwidth โ
bound by per-token overhead, not by the weights. The interesting number in
the file is therefore the 21.8x of headroom, not the 8.1x. You are right
about that too.
Thanks again โ the second pass was the one that found the actual claim.