512 vs 4k block size

[Myth]

Hey Guys,

I'm a SAN server administrator and we work in media rich files. I'm just wondering what the difference is between 512 vs 4k block size. It seems that I can buy HDD's from seagate with these two options. Which do you guys think would work best for streaming media to multiple computers and why? I'd appreciate your help.

Best,
Myth

 

[i386]

The main difference is efficiency, 4k blocks store more data and use "better" crc than 512b blocks*.
According to some papers from dell 4k storage devices would perform better in most benchmarks as 4k is the default block size in most file systems and would cause more overhead (+ increase latency) on 512b devices.

*512 byte blocksizes were used in professional hdds since the 1950's (and early 80's in consumer hdds).

More information about 4k: Advanced Format - Wikipedia

 

[Evan]

If you want to add them to the SAN you administer then you should check carefully if it supports what... may even need 518 or 520 byte block as some SAN use the extra for error correction etc.

Some OS’s like ESX want 512k blocks. (By that I mean 512n not even 512e)