Also, wow, that EOS thread about a heat sink. A heat sink is a device that you throw (sink) waste heat into so that it can be dissipated. The R5 has a huge heat sink—the mag alloy body. It doesn't matter how big the spreader is on the back of the PCB as long as it can can transfer that heat from the processor and sensor to the body as fast as it's generated. Given the 20-30 minute recording time, I'd say that's the sink (body) reaching it's capacity. This sounds very different from, say, a PC that's got inadequate cooling. Not sure about the lack of thermal compound—that picture was tiny—I suppose it could be an issue but only if it's heat transfer that's the problem not heat dissipation. But you don't put cooling fins (like you'd see on a CPU) on a thermal setup like this because fins are used to dissipate not transfer heat.
The problem* here seems to be that the sink (mag alloy) can't effectively dissipate the heat generated once it's full. This is why the R6 overheats faster despite processing half the information as the R5. No mag allow to sink heat to! I feel like folks are looking at this and saying "gosh it's not designed like my PC canon is dumb" without a pinch of thought about what's going on:
- Rate the sensor and processor generates heat. Can be mitigated by firmware (more efficient or less use of hardware) to some degree but there are also just the realities of the TDP of these components.
- Is the heat from the sensor and processor being pulled away quickly enough to prevent them from overheating (stability, eventually hardware damage).
- What do you do with that heat—where does it sink to?
- Once it's been sinked, how do you dissapate heat from the sink. PCs have big ass sinks with hundreds of fins because they're paired with big ass fans to remove the heat from the sink.
Where the problem in that stack lies greatly affects what Canon can do. If the entire thing is working as anticipated, I don't see how you fix* it w/o re-engineering the entire body.
In a perfect, perfect world there's a defect in a batch of Digics or sensors that's causing them to create more heat than their spec'd TDP. The delay is to fix that mfg problem but wow that's idle speculation for the ages. This is starting to feel an awful lot like "Canon is re-working the 5D4 to add better 4K codecs!" and folks need to get their own expectations in order.
*I am still not 100% convinced there is a "problem" here except for Canon's marketing group which headlined 8K and then said "uhhh well sorta" in conjunction with not putting the bodies in the hands of anyone except explorer.