To be clear, I think the original plan (up until mid-2022 at least) was a launch in holiday 2023, but I wouldn't rule out a delay into 2024. If it does get pushed into 2024, though, I would expect it early in the year, not late.
On the CPU front, eight A78C cores seems almost certain. It's a bit more difficult to extract CPU power curves from Nvidia's Jetson tool (and the A78AE isn't
exactly the same as the A78C), but from what I can see I'd guess around a 1.7 or 1.8Ghz clock speed. For 8N that would be around 1.2GHz. Unlike the GPU, though, an 8 core A78C is very much viable on 8nm.
Just curious, but when you're looking at Tflops to bandwidth ratios of Ampere cards, are you using the official Tflops figure for the cards, or calculating it from the actual clock speed the cards achieve in game? The reason I ask is that Nvidia's official figures actually underestimate the Tflops by a bit, as the GPUs typically run at a higher clock than the advertised boost clock. For example, the RTX 3070 advertises a boost clock of 1,725MHz, for 20.31 Tflops, but
in game clock speeds average around 1,890MHz, which would give 22.26 Tflops. With 448GB/s of bandwidth, the former would come out at 22.06GB/s per Tflop, but the latter would give us 20.13GB/s per Tflop.
With standard LPDDR5 at 102GB/s and 25GB/s for the CPU, that would give a cap of 3.5Tflops if we're using official figures, or 3.8Tflops if we're basing it off actual in-game clocks. In either case I think they could manage 3.4Tflops without being any more bandwidth constrained than other Ampere GPUs. Of course any additional bandwidth on top of that would surely help, so I definitely wouldn't complain if it were LPDDR5X.
Do any games actually use a 307MHz clock on Switch? My understanding is that it was replaced prior to launch with the 384MHz clock, which has a 1:2 ratio with the 768MHz docked clock (and then a 460MHz portable clock was added too, reducing the ratio further).
In any case, my reasoning for the 1.1GHz docked clock is partly the clean 1:2 ratio like the 384MHz/768MHz clocks Switch launched with, but also power consumption and bandwidth limits. A 1.1GHz clock would put power consumption at around 10W for the GPU, so maybe around 15W for the full system. They're not concerned about battery life in docked mode, but they still have to cool the system, and with a similar thickness and small fan setup it would be tricky to cool much more than 15W without the fan becoming distractingly loud.
On the memory bandwidth side, as discussed by
@Look over there above, there's only so much performance they can get before they become bandwidth-starved. Comparing to desktop Ampere GPUs, a 1.1GHz clock would put them in a similar bandwidth per Tflops ratio. Maybe they could get away with 1.2GHz if we're looking at in-game Ampere clocks for our comparison.
We don't know if they'll ship with binned GPU cores, but personally I don't think it's very likely. Binning GPU cores is common on console chips as a way to improve yields, but those chips are typically pretty large. The PS5 SoC is around 300mm² and the XBSX SoC is 360mm², and yields get worse the bigger the chip, so you basically need to disable something to get decent yields on a chip that big. By comparison, if T239 is on TSMC 4N, then it's going to be a tiny chip, well under 100mm². Yields should be good enough with a die that small that there's no need for binning out any cores.
On disabling the SMs, I don't think it would need a restart, but it would require much more careful management than the current change from docked to handheld. The SMs being disabled would have code running on them at the time, so that in-flight code and data would need to be migrated to other SMs. Developers would also have to account for the two different GPU configurations when working on handheld and docked modes, which would be more work than the current "identical GPU at different clocks" paradigm.
Regarding taping out in 2022, here are a list of products Nvidia taped out in 2022:
Hopper: TSMC 4N
Lovelace: TSMC 4N
T239: ?
Grace: TSMC 4N
It's not exactly a difficult game of fill-in-the-blank.