Mac Mini Server or iMac for Handbrake Encoding?

[martinm0]

I do a lot of Handbrake encoding and really want a workhorse I can beat the snot out of. I picked up a mini server and have been running it for a few days (big buck bunny test of 6:50 @ 34.976871 fps). In comparison, my 2011 2.0 i7 MPB with the same CPU, but with an ATI GPU, did the same big buck bunny test in 6:21 @ 37.774349 fps). There are tons of other benchmarks for a variety of hardware in these discussions:

https://forums.macrumors.com/threads/1119583/
https://forums.macrumors.com/threads/1111126/

Based on these other threads and benchmarks, would the base 2011 21.5" iMac 2.5 i5 really be as fast as my current MPB and a bit faster than the mini server for encoding? It seems that the GPU must add some kick based on the numbers I'm seeing in my test of the server and the MBP (mini even had 8GB and 7200RPM, while MPB had 4GB and 5400RPM). Would the GPU in the iMacs give them more power, especially with the i5's lacking Hyper Threading?

Any info would be appreciated.

 

[dolphin842]

To me there are two possible explanations for the faster MBP encode:

1) The i7 part in there, despite being clocked the same, is actually a different SKU that allows for better performance.

2) Handbrake is getting an assist from the GPU for decoding, freeing up cycles for encoding. I wasn't aware of Handbrake being able to take advantage of GPU decoding though.

In any event, that big encoding benchmark thread seems to put the iMac 2.5 i5 in the same league as the mini server and MBP, so I don't think you'd be losing out on encoding speed either way (though things might stay a little cooler with the iMac over time!).