Powersaving on MP5.1 - Disable CPU or Cores

Roman78

macrumors regular
Original poster
May 7, 2018
246
59
Eifel - Germany
Since a week i can call me a proud owner of a Dual 6-Core MacPro 5.1. I also own a 1.1, 3.1 and 4.1 :D Now i was wondering if it is possible to reduce power consumption of this MP5.1 by software.

I always try to save power. For example I used next to the MP4.1 (110-280Watt) a Mini (21-38Watt). So i only switched to the MP4.1 when some power was needed. Or I experimented using the 3.1 with one or 2 CPUs and also swapped the X-Xeon (130W TDP) to an E-Xeon (95W TDP) and L-Xeon (50W TDP).

Now the MP5.1 already uses 150Watt idling and up to 330W on full CPU load. Most of the time i don't need 12 Cores 24 Threads. 4 Cores would do. So is there a Software solution to disable/enable Cores or one whole CPU?
 

tsialex

macrumors 603
Jun 13, 2016
5,596
6,414
Brazil
Since a week i can call me a proud owner of a Dual 6-Core MacPro 5.1. I also own a 1.1, 3.1 and 4.1 :D Now i was wondering if it is possible to reduce power consumption of this MP5.1 by software.

I always try to save power. For example I used next to the MP4.1 (110-280Watt) a Mini (21-38Watt). So i only switched to the MP4.1 when some power was needed. Or I experimented using the 3.1 with one or 2 CPUs and also swapped the X-Xeon (130W TDP) to an E-Xeon (95W TDP) and L-Xeon (50W TDP).

Now the MP5.1 already uses 150Watt idling and up to 330W on full CPU load. Most of the time i don't need 12 Cores 24 Threads. 4 Cores would do. So is there a Software solution to disable/enable Cores or one whole CPU?
I used another solution. I have dual and single trays, I only install the dual one when I'm compiling big projects or converting lots of videos. When I'm programming, studying and using things that don't parallelise, I use the single tray.

Single trays are cheap nowadays, less than $70, probably less than what I'll spend early with the dual one installed full time.
 

Roman78

macrumors regular
Original poster
May 7, 2018
246
59
Eifel - Germany
That's an idea. Single Tray and 60 or 80 Watt Xeon. I give that a try. I still have the 4.1 i could use as test. Does the 4.1 2009 CPU board works on the 5.1 2010? E5645 80Watt CPU is 13 Euro.

TDP is not the power consumption, so will a quad core be more power effective than a Six-core?

I have some CPUs at home, i will try those first. Maybe i go for a 60-Watt L-Xeon, but those are only available in China.
 

tsialex

macrumors 603
Jun 13, 2016
5,596
6,414
Brazil
That's an idea. Single Tray and 60 or 80 Watt Xeon. I give that a try. I still have the 4.1 i could use as test. E5645 80Watt CPU is 13 Euro.

TDP is not the power consumption, so will a quad core be more power effective than a Six-core?

I have some CPUs at home, i will try those first. Maybe i go for a 60-Watt L-Xeon, but those are only available in China.
I like X5677 a lot, fastest single core possible with a Mac Pro, just four cores to power.
 

tsialex

macrumors 603
Jun 13, 2016
5,596
6,414
Brazil
That is also a 130W CPU.

Do you know if a 4.1CPU Tray will work on a 5.1?

I wonder what CPUs will work. I found this list: https://forums.macrumors.com/threads/mac-pro-cpu-compatibility-list.1954766/ Maybe even a L5630 with a TDP of 40Watt would work.
X5677 is a 130W TDP Xeon, but it uses a lot less power than a X5680/X5690.

2009 trays will "work" with a MP5,1, but all Mac Pro fans will run at full RPM and you can't control it.

If you use the 2009 CPU tray for anything other than rapid tests with your mid-2010/mid-2012 Mac Pro, you won't like to work next to a jet engine.
 
Last edited:

Roman78

macrumors regular
Original poster
May 7, 2018
246
59
Eifel - Germany
Ok. Good to know.

At this moment the cheapest 5.1 Tray i found is around 140 Euros include PP.

On the other hand 140€ are 540KW/h (0.26€ per KW/h) Now i first have to check how low a MP can go whit a Single CPU, but say it runs on 80-160w instead of 150-330W. So a difference from 50-170w, maybe average saving of 100W (this is just an estimated value) So i could use the MP5.1 Dual for about 5400 Hours before the investment becomes affordable. By using the MP maybe 10 hours a week this would be 540 weeks or 10 years. Or did i made an error in my calculation?
 

tsialex

macrumors 603
Jun 13, 2016
5,596
6,414
Brazil
Ok. Good to know.

At this moment the cheapest 5.1 Tray i found is around 140 Euros include PP.

On the other hand 140€ are 540KW/h (0.26€ per KW/h) Now i first have to check how low a MP can go whit a Single CPU, but say it runs on 80-160w instead of 150-330W. So a difference from 50-170w, maybe average saving of 100W (this is just an estimated value) So i could use the MP5.1 Dual for about 5400 Hours before the investment becomes affordable. By using the MP maybe 10 hours a week this would be 540 weeks or 10 years. Or did i made an error in my calculation?
I use it 24/7/365.
 

Roman78

macrumors regular
Original poster
May 7, 2018
246
59
Eifel - Germany
Well that's something different, indeed. For me it is just one of many computers at home. For Work I have an i5 running windows. I can not convince my team manager to get me an Apple. :D
 

bsbeamer

macrumors 68030
Sep 19, 2012
2,611
1,268
After booting MP5,1 and just letting it "sit" with monitor on, it idles around 250 watts on power meter on UPS battery backup. This is with 1 NVMe, 7 SATA SSD, Sapphire Pulse RX 580 8GB, USB3 card, 2 x 3.46 (two X5690's), 128GB RAM. BootROM 140.0.0.0.0 and Mojave 10.14.3 18D109.
 

IndioX

macrumors regular
Oct 1, 2018
199
72
austria/europe
my main cMP use near 300W on idle (plus 2 x 27" apple LED) and runs 16-18 hours a day for most of the year.
and 2 pieces of mini i7 and i5 2012 as server 24/7/365
6 SAT receiver and 3 TVs (one plasma) with AV-receivers allways in standby if not used
 

Macschrauber

macrumors 6502a
Dec 27, 2015
522
230
Germany
Very back in the years, thinking bout Power Mac G5, there was a pram setting to disable one processor. Was used for troubleshooting.

Maybe there are some settings we are aware off...
 

Roman78

macrumors regular
Original poster
May 7, 2018
246
59
Eifel - Germany
I noticed yesterday while making the MP4.1 ready for sale, that the GPU also could be a large power consumer. In the MP4.1 i had the GTX680 and one X5680. That used about 100-110Watt idling. Now i moved the GTX680 to the MP5.1 (because this one has Metal support) and took the HD5770 from the 5.1 and moved it into the 4.1. Now the power consumption idling on the MP4.1 is about 140Watts. So the HD5770 took 30 Watts more idling.