Redo write statistics

I am trying to determine how fast it takes to write a block from the redo log buffer to the redo logs. If I am understanding the statistics in v$sysstat properly, in order to return the number of milliseconds per block write the equation should be as follows:

select (a.value*10/b.value)
from v$sysstat a, v$sysstat b
where a.name = 'redo write time'
and b.name = 'redo blocks written';

However, the number I am getting back is quite small (around 0.087). Shouldn't a write be around 2 to 10 ms? What am I missing here?

Thanks,
Tom

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