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Comment on 8GB RAM on M3 MacBook Pro 'Analogous to 16GB' on PCs, Claims Apple

Putting RAM physically closer to the CPU does allow you to utilize the RAM better. It’s physics.

If the RAM was 3x closer, would it somehow be faster? I’m looking for metrics. With the same stick of an my given DDR5, how much performance loss is there on a few example motherboards of your choice?

My point, again, is that yes, on paper, shorter wires means less opportunity for inductance issues, noise, voltage drop, cross-talk, etc. But this is all on paper.

It’s not like every motherboard manufacturer doesn’t know what they’re doing and Apple’s brilliant engineers somehow got a higher clock speed than what the RAM is rated for because… shorter wires?

Case in point: DDR4 is meant to operate at a maximum clock speed per the specs of DDR4. However, on plenty of motherboards that are overclock-capable will support memory that is more than 3x the clock of what DDR4 should be capable of. How does this work with memory that is not soldered into the motherboard?

Additionally, without overclocking, the memory is designed to operate at a clock speed. Will shorter traces to the RAM magically increase the capable clock speed of the RAM? Are these the “psychics” you’re referring to?

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Alexstarfire@lemmy.world ⁨11⁩ ⁨months⁩ ago
I know I’ve seen something about this topic. I want to say it was from LTT but I can’t find the video.

I didn’t say anything about it being faster. I said utilize it better. Lower latency can be a big help as it allows quicker access. Think of HDD vs SSD. The biggest advantage in the beginning was the much lower latency SSDs provided. Made things a lot snappier even if the speed/throughput wasn’t all that different.

I don’t know what kind of difference we’re taking about here, or how much real world preformance benefits there are but there’s a reason CPUs have caches on the die.

And that doesn’t include whatever other benefits shorter traces provide. Less voltage drop might be helpful.

But, flexibility must still be better than those gains else most manufacturers would have switched. At some point you start running out of better ways to improve performance though. That’s why things are going back to being integrated with the CPU again.

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- Synthead@lemmy.world ⁨11⁩ ⁨months⁩ ago
  
  Lower latency can be a big help as it allows quicker access
  
  How much latency? Consider the speed of electricity at a few centimeters.
  
  there’s a reason CPUs have caches on the die
  
  The static RAM on the die is a different type of memory that’s appropriate for the CPU to use. It’s not that short conductor lengths magically make it faster.
  
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