One of the nice feature of windows 7 for low memory system is ReadyBoost, a software component that uses flash memory as a cache to actually speed up the the performance(Ref-Wikipedia).
But If we take computer architecture as a whole into consideration, we have cache levels(L1, L2 etc) located in between processor and RAM. So If we use flash memory as a cache then where it actually resides in this hardware hierarchy and how the data or control flow takes place?
In simple words, my question is, does ReadyBoost actually extends the system cache level by exploiting the use of flash memory or does it extends the performance of RAM? Or Does it serve as a disk cache sitting in between RAM and HDD?
Anybody please explain me. Thanks.