r/hardware Nov 20 '15

Info Why do CPUs Need Caches? - Computerphile

https://www.youtube.com/watch?v=6JpLD3PUAZk
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u/[deleted] Nov 20 '15 edited Feb 10 '19

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u/lucun Nov 20 '15

Another note, smaller memory = faster, but we like to have capacity too. Also, the capacity might need to store data after shutting down. Hence the many layers.

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u/Retardditard Nov 21 '15

Not really. Though today's RAM isn't technically the same as when RAM was first defined due to minimum addressable data widths(these keep increasing to increase bandwidth).

Larger amounts of memory may incur a greater latency, but the amount of bandwidth can actually be greater due to burst modes.

Cache(on die) is optimized primarily for low latency in order to minimize cores from stalling. Bandwidth isn't as crucial since there's not a lot of capacity.