Currently I have an e3300 in my unRAID box, but I could exchange it to an e8400, but I am wondering about the power consumption impact of that move.

 

I know that by default even the e3300 is overkill for unRAID, but I run vmware and could benefit from the performance gain a lot.

 

My only concern is that I don't really know how much more power the e8400 would suck? The max TDP for both CPU is 65W. I suppose the power consumption in idle wouldn't be so much different, but given vmware and 1-2 virtual machines running I guess the CPU is not idling most of the time even if the virtual machines itslef are not doing CPU demanding tasks. Is this assumption correct?

 

So say I have 2 virtual machines running at the same time but most of the time they are both running on low CPU utilization, would it suck a lot more power with e8400?

There will be additional energy used as the cache is larger on the e8400.

 

How much will be used depends entirely on the load with the virtual machines.

When they get busy you will see the server's power usage spike.

Yet it will not be that much more vs the celeron when each is running flat out.

You have to consider both CPU's are rated at 65w TDP.

If you have an e8400 just sitting around why not just try it out?  I assume you have some way to measure the power use of the server (i.e. kill-a-watt meter).