# Does CPU Performance increase if Cache store is full ?

**URL:** <https://community.wowza.com/t/does-cpu-performance-increase-if-cache-store-is-full/40963>\
**Category:** Wowza Streaming Engine\
**Created:** [November 26, 2014, 2:13am UTC](https://community.wowza.com/t/does-cpu-performance-increase-if-cache-store-is-full/40963 "2014-11-26T02:13:37Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Manh\_Hung\_Nguyen](https://avatars.discourse-cdn.com/v4/letter/m/c4cdca/32.png) [@Manh\_Hung\_Nguyen](https://community.wowza.com/u/Manh_Hung_Nguyen)\
**Post date:** [November 26, 2014, 2:13am UTC](https://community.wowza.com/t/does-cpu-performance-increase-if-cache-store-is-full/40963/1 "2014-11-26T02:13:37Z")

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Hi everyone,

I’m using 50 GB Cache store for VoD caching.

However the Cahce capacity is usually full.

May it cause increasing CPU performance, especially %iowait ?

Thanks.

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**Author:** ![Andrew\_Kennedy1](https://avatars.discourse-cdn.com/v4/letter/a/278dde/32.png) [@Andrew\_Kennedy1](https://community.wowza.com/u/Andrew_Kennedy1)\
**Post date:** [November 26, 2014, 8:40am UTC](https://community.wowza.com/t/does-cpu-performance-increase-if-cache-store-is-full/40963/2 "2014-11-26T08:40:39Z")

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Hi,

CPU and IO will go up once the cache is full and additional content is requested by clients. If the content can not be cached then Wowza will retrieve segments as needed, however this means they will be very small reads rather than the blocksize defined in the MediaCache configuration. This will result in a several things occuring

- More connections to the store - be it HTTP requests or disk reads (depends on the type of store)

- As the reads will be much smaller then more IO

- More threads will be constant use as they will be constantly getting data rather getting and caching it

- Overall more CPU

Andrew.