The Mac Pro First Generation is an Intel Xeon-based workstation computer manufactured by Apple Inc. between the years of 2006 and 2013.

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Temperatures and Amps on the core & FBDIMM's

Dear All!

After upgrading my Mac Pro 3,1 with INTEL Quad Xeon 3,2GHz processors, 32Gb of RAM, USB 3 card and an SSD as startup disc, I installed iStat Menu to check whether or not my Mac Pro was doing OK.

So far, a few points I worry about; I hope somebody out there might have a suggestion for me:

- The "AMB IC FBDIMM in Riser A Slot 1 and 2" run at 128 degrees C all the time. Isn't that too much?

- Fans stay below 800rpm almost all the time. They would boost up in case the Mac gets too hot, right?

- CPU A-core draws in about 25Amps, while B draws in about 50Amps. That's way too much, right?

I'm talking about idle mode here - no heavy lifting - although I do realise that the CPU's rarely go below 13% load.

Every help is greatly appreciated.

All the best,

Marco

Answered! View the answer I have this problem too

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A major upgrade like this requires you to resync the fans. This software is on your original system installation DVD.

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Thanks for your help Mayer, I appreciate it. So basically an SMC reset is fine? I did that just now. I should have the original DVD somewhere - but I do not recall in which box... What do you think about the amps the CPU's are drawing? Too much, right?

Thanks,

M.

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Here's some info on power consumption on the different MacPros:

https://support.apple.com/en-us/HT201796

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Hey Thanks for pointing me into the right directions! Much appreciated!

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Now that you have the fans working correctly, how your temps?

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Better! Especially the CPU cooled down, 37C for CPU A and 44C for CPU B. But the AMB IC on the FBDIMM's stays at 128C right from the start. So I guess there might be a wrong reading there. I will have, as Richard proposed, to check with an infrared thermometer.

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Marco

128 C or F? If its C that is very hot!

Fully Buffered DIMM (FB-DIMMs) can run hot and often require forced air cooling so you may have to add a fan and even look into heat sinks for the RAM if they don't already have them.

As far as your CPU's I have read some things online that say that amount of current is possible it seems high to me but perhaps someone else could weigh in on that aspect of it??

Hope I helped a little

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Celsius! But iStat Menu shows 128C right from the boot up. This temperature never changes. Could it be that the sensors are not working? I don't think the FBDIMMS get that hot right from the start?

I will look into that - how to fit one more cooler between the risers.

Regarding the CPU's, Mayer's answer helped a lot. I reset PRAM and SMC and that did the trick - resynced fans AND took the load of the CPU's which were constantly at over 50% - even in idle mode. now, they barely go above 20% under heavy load. In idle, they stay below 2%.

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I suppose it's possible your readings are not correct especially since they are reading that hot from first boot and it never changes and I am assuming the system is running ok nothing weird going on?

Any chance you have infrared thermometer so you could take a reading right of the dimms? Forgive me for being a salesmen but ifixit has one for $20 I think, but after doing the reset if the system is stable I would think you are ok.

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Thanks for the help. I do have an infrared thermometer, I just don't know in which box it's in (recently moved). Will do so as soon as I find it. The system is running very stable - no worries there. So I just think the reading is off. I did purchase FBDIMM's with slim heatsinks; I am worried that those (32GB) might be the problem - but still, 128C constant temperature seems odd to me.

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The "AMB IC FB-DIMM in Riser A Slot 1 and 2" run at 128 degrees C, because of the RAM that you installed on your system. It's reading error from iStat Menus.

Try different manufacture of RAM to find a better match for your system!

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Marco Battistella will be eternally grateful.
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