4 ms·

> The technical reason to put memory and the CPU/GPU on a single package is to decrease memory latency (and possibly boost operating frequency). You've got tha

> The technical reason to put memory and the CPU/GPU on a single package is to decrease memory latency (and possibly boost operating frequency). You've got that backwards, I think. Putting memory on package, or even just soldered on the PCB nearby rather than in removable DIMMs primarily helps hit higher frequencies or lower power at similar frequencies (GPUs and smartphones provide a wealth of examples). There's little or no impact on latency, because most DRAM latency occurs within the DRAM dies or inside the CPU's cache hierarchy rather than on the link between the CPU and DRAM.

sliken 4y ago
Seems to be both. One big advantage which is not visible on the M1 (which has a 128 bit wide memory), is the M1 pro, max, and ultra have 2x, 4x, and 8X the memory bandwidth. Something that's much harder on the x86-64 size, and (AFAIK) impossible on x86-64 laptop. The latency does seem improved in the last level cache and main memory, at least compared to AMD's Ryzen 5000 series. Sadly looks like Anandtech has lost the people who did the deep dives and I can't find similar latency numbers for cache and ram for the Ryzen 7000 series. Apple's power efficiency allows for a 512 bit wide memory system in a laptop, 4 times any x86-64 laptop. I do hope that AMD or Intel ups their game and allows for more aggressive memory systems on laptops. Only similar design I know of is the Xbox series X and PS5, which both use AMD chips with improved memory systems to keep from bottlenecking the iGPU.
- skibble 4y ago
  I think a big reason for Anandtech losing the deep dive expertise is that the founder of Anandtech, Anand Lal Shimpi, was hired by… Apple! That was a while ago (2014), but that sort of knowledge isn't easy to find I imagine.
  - geerlingguy 4y ago
    Many of the heavy hitters who used to test and write for Anandtech seem to have left too :(
  - sliken 4y ago
    Agreed, sadly he's not the only expert to leave.

sliken 4y ago

Seems to be both. One big advantage which is not visible on the M1 (which has a 128 bit wide memory), is the M1 pro, max, and ultra have 2x, 4x, and 8X the memory bandwidth. Something that's much harder on the x86-64 size, and (AFAIK) impossible on x86-64 laptop. The latency does seem improved in the last level cache and main memory, at least compared to AMD's Ryzen 5000 series. Sadly looks like Anandtech has lost the people who did the deep dives and I can't find similar latency numbers for cache and ram for the Ryzen 7000 series. Apple's power efficiency allows for a 512 bit wide memory system in a laptop, 4 times any x86-64 laptop. I do hope that AMD or Intel ups their game and allows for more aggressive memory systems on laptops. Only similar design I know of is the Xbox series X and PS5, which both use AMD chips with improved memory systems to keep from bottlenecking the iGPU.

skibble 4y ago
I think a big reason for Anandtech losing the deep dive expertise is that the founder of Anandtech, Anand Lal Shimpi, was hired by… Apple! That was a while ago (2014), but that sort of knowledge isn't easy to find I imagine.
- geerlingguy 4y ago
  Many of the heavy hitters who used to test and write for Anandtech seem to have left too :(
- sliken 4y ago
  Agreed, sadly he's not the only expert to leave.