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A comment on Apple M3 Ultra. Parent comment

Re:Apple M3 Ultra by imatrix on Thursday March 06, 2025 @07:49AM (#43279632)
This is not correct. It is like VRAM, not like normal PC RAM.

Lowest latency of DDR5-6400 on normal PC starting at 60ns+

Lowest latency of VRAM on GeForce RTX 4090 starting at 14 ns

Lowest latency of Apple M1 Memory starting at 5 ns, its more like L3 cache

And on Apple M chip, this ultrafast memory is available for CPU, GPU and NPU.

https://www.anandtech.com/show/17024/apple-m1-max-performanc... https://chipsandcheese.com/p/microbenchmarking-nvidias-rtx-4...

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Re:Apple M3 Ultra by adgjlsfhk1 on Thursday March 06, 2025 @12:38PM (#43282895)
You are misreading that chart. 5ns is the L2 latency. The ram latency from your source is 111 ms (once the size gets bigger than the size of the cache). The ram on a 4090 is 240 ns https://chipsandcheese.com/p/microbenchmarking-nvidias-rtx-4...
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