Hacker News Reader

Comment by Tepix | Hacker News Reader

Not all RAM is dirt cheap. RAM in DDR4 sockets is dirt cheap.

8GB of general-purpose RAM, regardless of form factor, is dirt cheap. In fact, not having the sockets might make it cheaper than socketed RAM in volume, since there are fewer parts in total.

Except, with Apple's new kit here, the RAM isn't simply some external chip soldered to the main board, it's actually on-die with the CPU silicon (and everything else in that silicon: GPU, memory controllers, etc).

So yes, arguably there are fewer parts (just one), but in the event of e.g. some bad RAM during manufacture, it's far more costly to throw out the chip containing that bad RAM.

No. It is not possible to make DRAM on the same silicon process as high-performance CPU logic. It is a myth that Apple Silicon includes the RAM on its die. Apple uses external LPDDR packages, just like everyone else, which you can clearly see in this photograph of the mac mini's CPU module: https://valkyrie.cdn.ifixit.com/media/2021/01/28102657/m1_ch...

Thanks for the correction, appreciated.

I don't think this is correct.

https://www.macobserver.com/analysis/understanding-apples-un... is an article which describes the architecture. It's not on-die, it's next to the CPU, basically as close as it could physically possibly be without being on the die.

Here's a photo of an M1 CPU:

https://www.techinreal.com/wp-content/uploads/2021/05/2feddf...

Those chips on the right side are LPDDR4x chips (which you can verify by googling the part numbers visible on them). They are "off-the-shelf" so to speak, not custom on-die memory.

Thanks for the correction, appreciated.

Reply on news.ycombinator.com