[adrr]

If you need raw speed for storage why mess around with EBS or any other network storage device. Your case with videos. You could shove the videos for permanent storage on S3 and then use I2 instance and it's ephemeral storage to serve videos. I think I2 NVME drives push 250,000 IOPS per drive and you can get up to 8 drives per instance.

[peferron]

If you expect your read/writes to be mostly sequential, and about throughput more than about IOPS, then local HDDs (d2 or h1) may even do the job for a lower $/GB. (You may even be able to serve straight from S3 or CloudFront but that's veering off the topic.)