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Overheating Memory Module A1?

Z

zero9ine

macrumors newbie
Original poster
Nov 5, 2007
6
0
Australia
I recently (a week or more ago) bought 4gb (x2 2GB sticks) Crucial ram to upgrade my Mac Pro - these look exactly the same as the Apple ones just with a Crucial sticker.

I put the 2gb sticks in A1 and A2 slots and A3, A4, B1 and B2 the original 4x 512mb sticks I got from Apple on the initial purchase.

Are these temps normal, I haven't noticed any problems from the time of installing the memory to now and System Profiler reports everything is OK:

Temperature Monitor:
2007-11-06 10:46:28 +0900

Ambient Air: 23.0℃
CPU A Heatsink: 27.0℃
CPU B Heatsink: 28.0℃
Expansion Slots: 31.0℃
Hard Drive Bay 1: 26.0℃
Hard Drive Bay 2: 26.0℃
Hard Drive Bay 3: 25.0℃
Hard Drive Bay 4: 26.0℃
Memory Bank A Point 1: 32.0℃
Memory Bank A Point 2: 38.0℃
Memory Bank A Point 3: 39.0℃
Memory Bank B Point 1: 31.0℃
Memory Bank B Point 2: 34.0℃
Memory Bank B Point 3: 33.0℃
Memory Module A1: 80.0℃ <-- Concern?
Memory Module A2: 53.0℃
Memory Module A3: 50.0℃
Memory Module A4: 47.0℃
Memory Module B1: 49.0℃
Memory Module B2: 51.0℃
Northbridge Heat Sink: 58.0℃
Power Supply Location 1: 34.0℃
Power Supply Location 2: 38.0℃
SMART Disk ST3160812AS P (4LS4CJ4Q): 34.0℃
CPU Core 1: 30.0℃
CPU Core 2: 32.0℃
CPU Core 3: 30.0℃
CPU Core 4: 32.0℃

Thanks for the Feedback.
 

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Swap A1 and A2 to see if it the problem follows the module, or stays with the slot.

By the way, the correct installation would be

A1- 2 Gb
A2- 2 Gb

B1- 2 Gb
B2- 2 Gb

A3- 512
A4 -512

Part of the problem with the FBDIMM implementation is that all access to A3 and A4 have to first go through A1 and A2 and are processed by the management chips physically on the A1 and A2 FB-DIMMs.

So if you have 44% of your memory in A3 and A4, then you are loading down the A1 and A2 FB-DIMMs unnecessarily, which may be contributing to the overheating. Plus, the latency on the slots 3 and 4 is terrible, so the more time you spend accessing these slots, the slower your machine is.
 
CanadaRAM said:
Swap A1 and A2 to see if it the problem follows the module, or stays with the slot.

By the way, the correct installation would be

A1- 2 Gb
A2- 2 Gb

B1- 2 Gb
B2- 2 Gb

A3- 512
A4 -512

Part of the problem with the FBDIMM implementation is that all access to A3 and A4 have to first go through A1 and A2 and are processed by the management chips physically on the A1 and A2 FB-DIMMs.

So if you have 44% of your memory in A3 and A4, then you are loading down the A1 and A2 FB-DIMMs unnecessarily, which may be contributing to the overheating. Plus, the latency on the slots 3 and 4 is terrible, so the more time you spend accessing these slots, the slower your machine is.
Click to expand...

Ok I'll try to swap the sticks around between A1 / A2, I was thinking of doing that and seeing if it follows.

I only have 6 GB total in the machine, as mentioned 2x 2gb sticks and 4x 512's

How can I lay those out?

A1 - 2gb
A2 - 2gb

B1 - 512mb
B2 - 512mb
B3 - 512mb
B4 - 512mb

as I have according to the manual is to setup like below:

A1 - 2gb
A2 - 2gb
A3 - 512mb
A4 - 512mb

B1 - 512mb
B2 - 512mb

Thanks for the replies again.
 
CanadaRAM said:
OK, I misread the original post. Option 2 above is the standard way of doing it, I would be curious whether the temps drop on A1 if you redo it as Option 1 with nothing 'above' the 2 Gb modules.
Click to expand...

Ok thanks.

I'll move the memory as you suggest:

A1 - 2gb
A2 - 2gb

B1 - 512mb
B2 - 512mb
B3 - 512mb
B4 - 512mb

Then if no change ill swap A1 and A2 first see if the temp stays in that spot or changes to A2.

I'll report the changes here.
 
OK.
I changed the 2x 512's in A3 and A4 into B3 and B4 and the heat is as follows when I booted up and idled:

2007-11-06 12:07:13 +0900

Ambient Air: 23.0℃
CPU A Heatsink: 28.0℃
CPU B Heatsink: 28.0℃
Expansion Slots: 30.0℃
Hard Drive Bay 1: 25.0℃
Hard Drive Bay 2: 25.0℃
Hard Drive Bay 3: 25.0℃
Hard Drive Bay 4: 25.0℃
Memory Bank A Point 1: 29.0℃
Memory Bank A Point 2: 30.0℃
Memory Bank A Point 3: 30.0℃
Memory Bank B Point 1: 30.0℃
Memory Bank B Point 2: 32.0℃
Memory Bank B Point 3: 35.0℃
Memory Module A1: 64.0℃
Memory Module A2: 40.0℃
Memory Module B1: 49.0℃
Memory Module B2: 51.0℃
Northbridge Heat Sink: 51.0℃
Power Supply Location 1: 30.0℃
Power Supply Location 2: 33.0℃
SMART Disk ST3160812AS P (4LS4CJ4Q): 32.0℃
CPU Core 1: 30.0℃
CPU Core 2: 33.0℃
CPU Core 3: 31.0℃
CPU Core 4: 33.0℃
Memory Module B3: 44.0℃
Memory Module B4: 42.0℃

then the Memory Module A1 started to increase up to 69-78 degrees Celsius.

2007-11-06 12:29:46 +0900

Ambient Air: 23.0℃
CPU A Heatsink: 28.0℃
CPU B Heatsink: 30.0℃
Expansion Slots: 33.0℃
Hard Drive Bay 1: 26.0℃
Hard Drive Bay 2: 26.0℃
Hard Drive Bay 3: 25.0℃
Hard Drive Bay 4: 26.0℃
Memory Bank A Point 1: 35.0℃
Memory Bank A Point 2: 39.0℃
Memory Bank A Point 3: 35.0℃
Memory Bank B Point 1: 36.0℃
Memory Bank B Point 2: 42.0℃
Memory Bank B Point 3: 44.0℃
Memory Module A1: 78.0℃
Memory Module A2: 51.0℃
Memory Module B1: 62.0℃
Memory Module B2: 65.0℃
Northbridge Heat Sink: 66.0℃
Power Supply Location 1: 34.0℃
Power Supply Location 2: 37.0℃
SMART Disk ST3160812AS P (4LS4CJ4Q): 34.0℃
CPU Core 1: 32.0℃
CPU Core 2: 34.0℃
CPU Core 3: 31.0℃
CPU Core 4: 33.0℃
Memory Module B3: 55.0℃
Memory Module B4: 54.0℃

I presume loading the browser, mail, itunes and adium would add some load to it? i just put it back to what I was doing prior to reporting the heat increase.

Also I noticed when pulling out the Ram risers the A1 slot seems to sit near a heatsink?
 
Hmm..
Swapped A1 and A2 around and seems the high temps did follow the memory stick.

2007-11-06 13:01:20 +0900

Ambient Air: 23.0℃
CPU A Heatsink: 28.0℃
CPU B Heatsink: 30.0℃
Expansion Slots: 33.0℃
Hard Drive Bay 1: 26.0℃
Hard Drive Bay 2: 26.0℃
Hard Drive Bay 3: 26.0℃
Hard Drive Bay 4: 26.0℃
Memory Bank A Point 1: 34.0℃
Memory Bank A Point 2: 37.0℃
Memory Bank A Point 3: 35.0℃
Memory Bank B Point 1: 35.0℃
Memory Bank B Point 2: 40.0℃
Memory Bank B Point 3: 43.0℃
Memory Module A1: 49.0℃
Memory Module A2: 75.0℃
Memory Module B1: 59.0℃
Memory Module B2: 63.0℃
Northbridge Heat Sink: 64.0℃
Power Supply Location 1: 34.0℃
Power Supply Location 2: 37.0℃
SMART Disk ST3160812AS P (4LS4CJ4Q): 34.0℃
CPU Core 1: 31.0℃
CPU Core 2: 33.0℃
CPU Core 3: 31.0℃
CPU Core 4: 33.0℃
Memory Module B3: 54.0℃
Memory Module B4: 52.0℃

While a little bit cooler than 80degC still seems high I gather?
 
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