Will moving data from EBS to ephemeral storage improve MySQL query performance?

Question

I am using EBS volume to store MySQL data. I do have enough space on ephemeral device as well. I will move the data to /root/, provided it will improve the query performance

Answer 1

To the answer the actual question:

Ephemeral instance storage is faster than standard EBS (100 IOPS), and EBS performance may vary greatly. Standard EBS when used with RAID appears to offer superior speed over ephemeral.

It's also possible to pay for EBS IPOS volume types to achieve predicable and reliable I/O performance which can perform better than elphermal and again these can be used with RAID for further improvements. The cavet to that is it possble to use ephemeral SSD drives which would also be highly performant (hi1.4xlarge).

See EC2 Ephemeral Disks vs EBS Volumes in RAID, Performance Test: Amazon EBS vs. Instance Storage, and Features of Amazon EBS volumes