4 ms·

The Mac Studio has always had unified memory

kridsdale3 2y ago
All "Apple Silicon" products, going back to the first one, which was the iPhone 4.
angoragoats 2y ago
Fun fact: any PC with integrated graphics has also had unified memory (yep, including Intel Macs), for at least the past decade!
- sliken 2y ago
  True, but PCs are 128 bits wide, apple lets you upgrade to 256 bits wide (M4 pro), 512 bits wide (m3 Max) or 1024 bits wide (M2 Ultra). Unified memory is much more useful when you can get more bandwidth to it.
  - fulafel 2y ago
    Yep, there's no performance x86 CPUs on the market with ambitious GPUs, only laptop chips. Games are optimized for discrete GPUs, Apple didn't have that software inertia to deal with.
    - sliken 2y ago
      Sort of, obviously quite a few games are optimized for the PS5 and Xbox series X. GPU cores are generally identical between the iGPUs and the discrete GPUs. Adding a PCIe bus (high latency and low bandwidth) and having a separate memory pool doesn't create new opportunities for optimization. On the other hand having unified memory creates optimization opportunities, but even just making memcpy a noop can be useful as well.
      - fulafel 2y ago
        GPUs are all about (compute & memory) bandwidth. Using the same building blocks of compute units doesn't yet it go fast. You need a lot of compute units and a lot of bandwidth to feed them. The performance dependency on DGPUs doesn't come from the existance of a PCIe bus and partitioned memory, but from the fact that the software running on the DGPU is written for a system with high bandwidth memory like GDDR6X or HBM. It creates opportunities for optimization the same way as hardware properties and machine balances tend to, the software gets written, benchmarked and optimized against hardware with certain kinds of performance properties and constraints (like here compute/bandwidth balance and memory capacity, and whether CPU & GPU have shared memory).

All "Apple Silicon" products, going back to the first one, which was the iPhone 4.

Fun fact: any PC with integrated graphics has also had unified memory (yep, including Intel Macs), for at least the past decade!

sliken 2y ago
True, but PCs are 128 bits wide, apple lets you upgrade to 256 bits wide (M4 pro), 512 bits wide (m3 Max) or 1024 bits wide (M2 Ultra). Unified memory is much more useful when you can get more bandwidth to it.
- fulafel 2y ago
  Yep, there's no performance x86 CPUs on the market with ambitious GPUs, only laptop chips. Games are optimized for discrete GPUs, Apple didn't have that software inertia to deal with.
  - sliken 2y ago
    Sort of, obviously quite a few games are optimized for the PS5 and Xbox series X. GPU cores are generally identical between the iGPUs and the discrete GPUs. Adding a PCIe bus (high latency and low bandwidth) and having a separate memory pool doesn't create new opportunities for optimization. On the other hand having unified memory creates optimization opportunities, but even just making memcpy a noop can be useful as well.
    - fulafel 2y ago
      GPUs are all about (compute & memory) bandwidth. Using the same building blocks of compute units doesn't yet it go fast. You need a lot of compute units and a lot of bandwidth to feed them. The performance dependency on DGPUs doesn't come from the existance of a PCIe bus and partitioned memory, but from the fact that the software running on the DGPU is written for a system with high bandwidth memory like GDDR6X or HBM. It creates opportunities for optimization the same way as hardware properties and machine balances tend to, the software gets written, benchmarked and optimized against hardware with certain kinds of performance properties and constraints (like here compute/bandwidth balance and memory capacity, and whether CPU & GPU have shared memory).