# What is the minimum block size in Aerospike? **URL:** \ **Category:** How Aerospike Works\ **Created:** [April 16, 2015, 7:54am UTC](https://discuss.aerospike.com/t/what-is-the-minimum-block-size-in-aerospike/1182 "2015-04-16T07:54:08Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![architect](https://avatars.discourse-cdn.com/v4/letter/a/d26b3c/32.png) [@architect](https://discuss.aerospike.com/u/architect)\ **Post date:** [April 16, 2015, 7:54am UTC](https://discuss.aerospike.com/t/what-is-the-minimum-block-size-in-aerospike/1182/1 "2015-04-16T07:54:08Z")
The default one is 128k. What is the impact of reducing the block size below to 128K e.g. 64K, 32K,16K? ---
**Author:** ![kporter](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.aerospike.com/kporter/32/515_2.png) [@kporter](https://discuss.aerospike.com/u/kporter)\ **Post date:** [April 16, 2015, 10:26pm UTC](https://discuss.aerospike.com/t/what-is-the-minimum-block-size-in-aerospike/1182/2 "2015-04-16T22:26:20Z")
We do not enforce a minimum but do not recommend going below 128KB. That said, I am only sure we would not function if you were to drop below 128 Bytes since that is our minimum record size on disk. The configuration we ship normally has write-block-size set to 128 KB but the actual default, if parameter were left out of the config, is 1 MB. The write-block-size also determines the maximum record size so lowering one lowers the other. By varying block sizes with the dd command I can observe that the performance of my local SSD drops if I go below 128 KB. The highest performance I see is by using 128 KB but 256 KB is nearly the same. There is a noticeable, but not terrible, drop when using 512 or 1024 KB with 1024 performing a bit better than 512. Many users have a use case where they keep appending to records, so allowing larger records may, may in this case, also increase the amount of bandwidth being used for reads and writes.