Last block device in striped LV or soft RAID0 would have longer await?

[Magicloud Magiclouds <magicloud.magiclouds@gmail.com>]

Hello,
	As I am trying some configurations for storage solution. I found out 
that, the last block device (normally, by alphabet) in striped LV or 
soft RAID 0 will have longer await. Especially in high concurrency IO. 
The same time, its avgrq-sz is more than others, but rrqm/s, wrqm/s, r/s 
and w/s are almost the same.
	I do not know much inside of lvm or soft raid. So I wonder if this 
problem is reasonable.

Thanks.