Cache and Effect

[FruitBasketSilex]

What is CPU cache, (l2/l3), and what exactly changes, performance-wise when going from something like 2mb l2 cache to 16mb l2 cache?

[NeverNotExhausted]

It's basically super fast ram that's embedded into the CPU or whatever component your using and is designed to only be used for what the processor is doing right at that moment. L2 means level 2, L3 means level 3 etc.

 

At least that's how I understand it

[gilm0re3]

It's basically super fast ram that's embedded into the CPU or whatever component your using and is designed to only be used for what the processor is doing right at that moment. L2 means level 2, L3 means level 3 etc.

 

At least that's how I understand it

And L3 cache is faster than L2, and L2 is faster than L1.

[FruitBasketSilex]

It's basically super fast ram that's embedded into the CPU or whatever component your using and is designed to only be used for what the processor is doing right at that moment. L2 means level 2, L3 means level 3 etc.

At least that's how I understand it

What is its effect on performance, though?

[NeverNotExhausted]

What is its effect on performance, though?

 

Basically more is better. I don't know actual numbers though

[FruitBasketSilex]

Does @Faceman know?

[Bronzeman]

And L3 cache is faster than L2, and L2 is faster than L1.

 

It's the other way around, the lower the level the cache the closer to the cpu core it is and the faster it is.

 

Level 1 is by far the fastest and the difference in speed between level 2 and level 3 is not as significant as between lvl1 and lvl2.

 

It's memory which is far faster than RAM and reduces cpu idle time as it waits on data being retrieved from RAM and other slower media.

 

The affect it has depends on the program, however more is typically better.

 

CPU efficiency is greater with increased cache, modern CPUs have features such as prefetch to have required instructions loaded into the cache ahead of time ready for execution. It gets technical with the many implementations used by CPUs today. A great way of improving a cpu's efficiency is to improve the utilization of cache ensuring the CPU is constantly supplied with instructions.

[i_build_nanosuits]

It's the other way around, the lower the level the cache the closer to the cpu core it is and the faster it is.

 

Level 1 is by far the fastest and the difference in speed between level 2 and level 3 is not as significant as between lvl1 and lvl2.

 

It's memory which is far faster than RAM and reduces cpu idle time as it waits on data being retrieved from RAM and other slower media.

 

The affect it has depends on the program, however more is typically better.

 

CPU efficiency is greater with increased cache, modern CPUs have features such as prefetch to have required instructions loaded into the cache ahead of time ready for execution. It gets technical with the many implementations used by CPUs today. A great way of improving a cpu's efficiency is to improve the utilization of cache ensuring the CPU is constantly supplied with instructions.

perfect answer, 10/10

[Dabombinable]

And L3 cache is faster than L2, and L2 is faster than L1.

Its the other way around: L1 is the fastest, L3 the slowest.

[Guest]

Adding to the already good answer, CPU cache is based on SRAM, or Static RAM, which is constructed from transistors. The main memory of a system is made up of DRAM, Dynamic RAM, which is constructed from capacitors.

 

SRAM trades cost and complexity for pure speed, while DRAM trades performance for low cost. That's why we use DRAM at all instead of using SRAM for everything. The latter would be ideal as L1 cache is 100x faster than main memory, but that isn't viable from a cost and engineering standpoint.

[SteveGrabowski]

If you really want to know about caches:

 

 

 

 

Incredible course BTW.

[FruitBasketSilex]

It's the other way around, the lower the level the cache the closer to the cpu core it is and the faster it is.

Level 1 is by far the fastest and the difference in speed between level 2 and level 3 is not as significant as between lvl1 and lvl2.

It's memory which is far faster than RAM and reduces cpu idle time as it waits on data being retrieved from RAM and other slower media.

The affect it has depends on the program, however more is typically better.

CPU efficiency is greater with increased cache, modern CPUs have features such as prefetch to have required instructions loaded into the cache ahead of time ready for execution. It gets technical with the many implementations used by CPUs today. A great way of improving a cpu's efficiency is to improve the utilization of cache ensuring the CPU is constantly supplied with instructions.

That is one damn fine answer.