Ram Heat Sink

prechrchet

macrumors regular
Original poster
Mar 5, 2002
156
0
I have a Mac Pro 1,1. A week or so ago, I had the ram chips go bad on me. I replaced them with a set of these:

http://www.amazon.com/dp/B007G9Z670/ref=pe_175190_21431760_3p_M3T1_ST1_dp_1

Question: the old ram chips each had a heat sink attached to them. Do I need to remove them and place them on the new chips?

FWIW, I replaced the old video card with an ATI Radeon HD 4870, which does produce a fair amount of heat.
 

pastrychef

macrumors 601
Sep 15, 2006
4,520
1,020
New York City, NY
There has been people who have run their systems without the huge heatsinks on their RAM. Personally, I would be nervous about doing so. I remember how hot those modules got when I had my Mac Pro 1,1 and 3,1.

If you can remove the old heatsinks and use them on your new RAM, I think you should do it. However, removing them might be quite difficult.
 

pastrychef

macrumors 601
Sep 15, 2006
4,520
1,020
New York City, NY
I think maxupgrades.com used to sell the heatsinks, but I don't know if they still do.

Again, using the heatsinks is just my opinion. You can go with GermanyChris'es suggestion as well.
 

prechrchet

macrumors regular
Original poster
Mar 5, 2002
156
0
I've managed to get them off the old chips, next step is to see if I can fit them onto the new ones.
 

GraniteTheWolf

macrumors 6502
Mar 31, 2013
250
6
Wisconsin
I've managed to get them off the old chips, next step is to see if I can fit them onto the new ones.
You will want to use some non-conductive thermal paste/grease when you put them on the new ram. Just so ya dont accidentally fry the new ram or even your logic board by grounding things together with thermal paste. non-conductive paste doesn't have metals in it so it wont ground things out and cause shorts.

Im not sure how the old ram chips look without the heatsinks on them (im guessing they have a large metal plate covering them similar to xeon cpus with the plate covering the cores?)
 

ScottishCaptain

macrumors 6502a
Oct 4, 2008
872
467
You need those heat sinks.

The MacPro1,1 was designed to be a quiet system. The only way they could achieve that and keep the RAM at an acceptable operating temperature was to add those large heat sinks to the RAM.

If you do not have the Apple spec heat sinks, then the RAM will run hotter then it should and eventually fail. This has been my experience across four separate FBDIMM manufactures in my old MacPro1,1 system. It worked for a while, but when the RAM was heavily stressed (mostly through rendering and other RAM intensive tasks) things would start to go sideways and eventually the sticks would overheat and begin to throw ECC errors. Other times the stick would flat out fail and cause random parts of the system to crash.

Again, it's not a matter of *if* the FBDIMMs will fail, but when- if you don't have those Apple spec heat sinks on them. They are there for a reason. FBDIMMs run absurdly hot under normal circumstances. Without the proper heat sinks installed, they will happily hit 80-100°C temperatures.

-SC
 

paulrbeers

macrumors 68040
Dec 17, 2009
3,960
120
I've been running a 1,1 for well over a year with non-big heat sink memory with no errors reported. All slots taken up with 2GB sticks. The lower memory board seems to run cooler than the upper board, but neither get about 80C. Not had any stability problems even when running handbrake at full tilt for hours on end as well as multiple VM's.
 

666sheep

macrumors 68040
Dec 7, 2009
3,623
211
Poland
You need those heat sinks.

Again, it's not a matter of *if* the FBDIMMs will fail, but when- if you don't have those Apple spec heat sinks on them.
This is a myth comparable to "repair permissions" thing ;)

AMB on FBDIMMs is designed do work up to the 120°C. This is component responsible for 90% of FBDIMM heat. 80°C on load it's nothing for good quality RAM.

I use 8 sticks with flat heastinks since 4 years, my computer runs almost 24/7. No single ECC error, none of sticks died.

On the other hand: RAM fails, this with huge Apple heatsinks as well. It happens.
 

Tesselator

macrumors 601
Jan 9, 2008
4,601
4
Japan
The heatsinks are NOT needed for any of the DIMM models manufactured after 1GB modules became available. There is some 256 and 512KB DIMMs that will run very hot without them. There are no DIMMs of 2GB (yours) which need them at all.
 
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