CODEWITHSUNDEEP
cachingmemoryoperating-system
Eduard6421
Eduard6421

Reputation: 315

What are the trade-offs of larger cache memories ? Could we use one to replace secondary memory?

What are the disadvantages of using larger cache memories? Could we use just use a large enough cache memory so a secondary memory wouldn't be needed at all? I understand that the most compelling arguments are related to the cost of it / the problem of it's size. But if we assume that creating such a cache memory is possible, would it encounter any additional problems?

Upvotes: 1

Views: 1006

Answers (1)

mightyWOZ
mightyWOZ

Reputation: 8355

Many problems even if it was not expensive

Size will degrade the performance

Cache is fast because it’s very small compared to the main memory and hence it requires small amount of time to search it. If you build a large cache then it will not be able to perform at the same speed as the smaller counterpart.

Larger die area

Most of the DRAM chips only require a capacitor and a transistor to store a bit. SRAM on the other hand requires at least 6 transistors to make a single cell of memory. Which requires more area.

High power requirements

Because of the more transistors SRAM requires more power to operate. Which in turn generates more heat so you will have to handle the cooling problem.

So as you can see it’s not worth the effort given that today’s computers already achieve 90% hit ratio most of the time.

Upvotes: 1

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