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zvonryan

How is this eDRAM different from the memory hierarchy we know?

hofstee

@zvonryan Generally we think of the memory hierarchy as

  • Core
  • Register file
  • Caches
    • L1
    • L2
    • L3
  • Memory
  • Storage

So now we just change memory to be

  • Memory
    • eDRAM
    • DDR

Of course this depends on how it's used. If it's used like an LLC this is fairly accurate. If you're using it as high bandwidth scratchpad I guess it would be more like a fork in the hierarchy next to DDR rather than above it.

rmanne

@hofstee if this is the case, even if a cache hit now is even less costly and is more likely, a cache miss would be even more costly right? Instead of just 3 layers of caching, now there are 4.

hofstee

@rmanne yes I think that would be the case.