Hi Amy,
I've had an opportuniy to run some tests with the new BIOS and quiet/balanced/performance modes and have some very intersting results but a question at the end.
For testing purposes I ran msconfig.exe and restarted by machine in diagnostic mode so all extraneous services had been stopped. I then ran a number of different tests using each of the modes selected in the BIOS. Here are the results:
1. Visual Studio Solution Build (each time I clean the build.) This is a real-world test of the sort of thing I do throughout the day and usually drives the fans mental (but not on my 3 year old Yoga 2 Pro which is as quiet as a mouse)
- Quiet Mode: Run 1 - 1m 25s, Run - 1m 06s, Run 3 - 1m 06s, Run 4 - 1m 06s
- Balanced Mode: Run 1 - 1m 25s, Run 2 - 1m 05s, Run 3 - 1m 05s, Run 4 - 1m 06s
- Conclusion - unfortunately I didn't run this in performance mode but the timings really were exactly the same but I did think the quiet mode was noticeably quieter throughout the tests.
2. Performance Test from which I only ran the CPU benchmark
- Quiet Mode: Run 1 : 5752, Run 2: 5787, Run 3: 5792
- Balanced Mode: Run 1: 5758, Run 2: 5752, Run 3: 5856
- Performance Mode: Run 1: 5768
- Conclusion - again no noticeable difference.
3. Blender Raytrace using demo file Fishy Cat
- Quiet Mode: 1m 45s
- Balanced 2m 14s
- Performance: 2m 08s
- Conclusion - now we're talking... but wait Quiet mode is not only quiet but much faster!! What's going on! This is when I started running HWMonitor to see what was going on in the CPU and discovered why Quiet is so much better and problem should be always on. Here's what I found:
- Quiet Mode: Max 87C and clock speed flipping between 3029Mhz and 3192Mhz
- Balanced Mode: Max 96C and clock speed shifting between 399Mhz and 3495Mhz
- Performance Mode: much the same as balanced but seems to spend less time at 399Mhz.
- Theory - I think Quiet focuses on keeping the temperature down by controlling the Mhz but that just happens to end up much faster - a bit like saying 'slow and steady wins the race'. Performance/Balanced however try for more raw power but spending longer throttling back to 399Mhz given the critical temperatures - a bit like sprinting and running out of puff and taking longer to recover.
So, great news, Quiet seems like a real win.
However, when I used msconfig.exe to get back to normal and have all my services running again I discovered a couple of weird things:
- CPU Benchmark now returned 5508 and 5350 in two separate runs
- Blender now took 2mins 8secs to render
- Theory - I might have thought that other processes were simply consuming processor time making these take longer (I did change the CPU benchmark to run in a higher priority to try and mitigate for this.) However, what I noticed when running blender was the temperature now hovered at 71C and the Mhz oscillated between 2583Mhz and 2896Mhz both a lot less than previously. I also tried changing the power plan from balanced to performance but that made no difference.
Question
So I'm left with a question. Is there a service that's limiting the performance of the CPU? And whilst I'm here - is this anything to do with the constant logging of the following in the event log:
The speed of processor 3 in group 0 is being limited by system firmware. The processor has been in this reduced performance state for 71 seconds since the last report.
which is being logged by Microsoft-Windows-Kernel-Processor-Power.
And finally
Amy, I hope my findings above are useful to you. My initial feelings are you've done some great work on getting this BIOS written and I'm very grateful. I still get the feeling the fans themselves are a little noisy (especially compared to the Yoga 2 Pro) but at least now they're not spinning up quite so fast now.