Fast storage I/O
It is counter-productive to have a RAID 1 mirrored disk in place because RAID 1 slows down the write access speed to the drive. A RAID 1 or RAID 10 is not tailored for video streaming because the mirroring of data is unnecessary. It is better to opt for a RAID 0, a RAID 5 or maybe no RAID at all
It is better to choose a CPU with at least 4 cores to stream videos since the streaming jobs can be split up between several cores of the CPU.
Network adapter speed
The usual 100Mbits network adapter will quickly be to slow for streaming videos. It is important to choose a dedicated server with at least a fast (1 Gbps) network adapter.
SSD or HDD?
SSD is still very expensive as compared to HDD but there are in general five times faster than HDD. Choosing between SSD and HDD may be a headache. Keep in mind that if you need a lot of space, go for HDD drives. If you need a lot of speed, go for SSD drives. Using a RAID 0 on HDD drives speeds up the I/O performance.
This is a very important parameter before buying a dedicated web hosting. The content of your videos may infringe the terms of the web hosting company. It is important to read the acceptable use terms before ordering a web hosting subscription.