How mSSD Hard Drive Acceleration Cache improves performance?

I am looking forward to buy a laptop and while configuring online from HP's site for model dv6tqe

https://www.shopping.hp.com/webapp/shopping/cart_detail.do?pageLink=true&bvLoadCart=1&action=add&disp_msg=0

one of the configuration option was

32GB mSSD Hard Drive Acceleration Cache and it costs $50

I have no idea what mSSD Hard Drive Acceleration Cache is used for and how it will improve the performance of the laptop.

for hard drive there are two options I can choose

5400 RPM 1TB hard drive
160 GB SSD for $200

is mSSD Hard Drive Acceleration Cache of no use if i choose to include SSD drive?

Solution 1:

The 32 GB mSSD is used to cache frequently used data and program files, speeding up access to them. Essentially it works the same as hybrid drives like the Momentus XT, except the cache is larger.
Edit: I believe it's basically an implementation of Intel's Smart Response Technology, the successor to Intel Turbo Memory.

If you choose an SSD for primary storage, then the cache is probably useless, yes, unless you can somehow use it as a regular hard drive, in which case it's up to you to decide whether 32 GB of extra solid-state storage is worth $50.