Has anyone noticed that Lion consumes more resources than Snow Leopard thus causing faster battery discharge?
YMMV, but it would be interesting to see of others can get similar results. Do you suppose Lion 7.3 will increase or decrease resource usage and what affect will it have on battery life?
I called Apple about the battery discharge issue on my 2 week old MacBook Pro with Lion 7.2. I was only getting about 1/2 of the 7.7 WIFI hours advertised. They gave me the usual "if depends" on WIFI, system settings, applications, etc., i.e. such things as cpu and memory load (paging/swapping=>disk i/o), other disk activity, and a few other things.
My large expenditure on the new MacBook spurred me to investigate what was going on using the Activity monitor. I configured my old MacBook Pro (mid 2009) and my new MacBook Pro (late 2011) with the same system preferences. I reset both the PRAM and SMC on both machines to maximize the battery charge (documented elsewhere).
Obviously, a direct hardware comparison would not be meaningful but when you look at the operating systems there is a significant difference between Snow Leopard OS X 10.6.8 and Lion OS X 10.7.2. Lion uses much more resources than Snow Leopard.
The first value I list is for OS X 10.6.8 and the second for OS X 10.7.2. I tried numerous other combinations but these nicely summarizes my results.
1) I started with only the Activity monitor, iTunes Helper, and Epson EEventmanager manager running, No WIFI or any other user processes
CPU % idle : 98.75 vs 99.4 (i.e. both machines were literally idle)
No. of threads : 179 vs 277 --> + 55%
Kernel threads : 60 vs 82 --> +37%
Processes : 41 vs 54 --> +32%
Wired Memory MB : 480 vs 864 --> +80%
Active Memory MB : 198 vs 407 --> +106%
Memory Used GB : 0.808 vs 1.32 --> +63%
Percentage of 4 GB : 20% vs 33% --> +65%
Virtual Machine size GB : 96 vs 149 --> +55%
2) With WIFI and Safari added
CPU % usage : 72.9 vs 91.02 (i.e. both machines were not very busy)
No. of threads : 253 vs 376 --> +49%
Kernel threads : 60 vs 82 --> +37%
Processes : 51 vs 63 --> +24%
Wired Memory MB : 669 vs 1007 --> +51%
Active Memory MB : 600 vs 1190 --> +98%
Memory Used GB : 1.57 vs 2.47 --> +57%
Percentage of 4 GB : 39% vs 62% --> +59%
Virtual Machine size GB : 131 vs 191 --> +46%
Look especially at the percentage of memory used. In either case, I measured no paging nor swapping. But, as you can see, with the increase of memory used with Lion when WIFI and Safari were added you could quickly push the memory as more process are added and start paging and swapping to/from disk hence use more battery charge.
The increase in number of threads, processes, memory usage, virtual machine size, and WIFI activity would imply that Lion would have to consume more battery charge than Snow Leopard as you use more cpu/memory to chase more threads.
I looked at WIFI usage and it involves a lot of chatter between the computer and the internet. Over time a lot of packets are sent/received even when no data is being passed and would be a drain on the battery. There would be a greater drain when there is data passed because of the additional CPU and memory needed. But, in todays world, you cannot run without an ethernet or WIFI connection because of the dependency on the information/data on internet cloud.
MacBook Pro 13", mid 2009, OS X 10.6.8, 2.5 GHz Intel Core 2 Duo, 4GB 1067 MHz DDR3, 5400 rpm Hard Drive
MacBook Pro 15", late 2011,OS X 10.7.2, 2.4 GHZ Inter Core i7, 8 GB 1333 MHz DDR3, 7500 rpm Hard Drive