On 01/10/11 5:41 PM, mcclnx mcc wrote: > 2. put two MD1000 on same PERC 6/E adapter will cause battery life shorter? raid batteries only get used when your power fails while the system is running, and are used to maintain the write cache so when power is restored any dirty data in the cache can be committed to disk. they should last for their shelf life, which is generally 5 years from date of deployment (I don't know Dell's spec on the Perc 6/E, I just mean in general). your other questions re relative performance should be tested with a simulation of your production sorts of workload, and other people's experience will have little bearing on your usage.