I'm getting mad - sixth memory stick dead in Mac Pro 2008

Spacedust

macrumors 6502a
Original poster
May 24, 2009
934
91
Micron is making the most horrible memories I've ever seen. Out of 8 stick 6 are dead.

So far other failed sticks were replaced with Micron (the same model), Kingston , Qimonda, Hynix, Nanya. Almost huge collection of different brands working together :) I think I'm only missing Elixir, FCM, GoodRAM and CSX :p

Now I'm going to get cheap Qimonda sticks with large heatsinks (for the first time) and we will see how these will perform...
 

G4DP

macrumors 65816
Mar 28, 2007
1,451
3
Micron is making the most horrible memories I've ever seen. Out of 8 stick 6 are dead.

So far other failed sticks were replaced with Micron (the same model), Kingston , Qimonda, Hynix, Nanya. Almost huge collection of different brands working together :) I think I'm only missing Elixir, FCM, GoodRAM and CSX :p

Now I'm going to get cheap Qimonda sticks with large heatsinks (for the first time) and we will see how these will perform...
This is the first time you've gotten ones with the correct Heat Sinks?
 

paulrbeers

macrumors 68040
Dec 17, 2009
3,960
120
Now I'm going to get cheap Qimonda sticks with large heatsinks (for the first time) and we will see how these will perform...
Sooo you are now switching to the Apple recommended heat sinks and wonder why all the others died..... :rolleyes:
 

goMac

macrumors 604
Apr 15, 2004
7,027
1,052
Pretty sure this is why the heat sinks aren't a suggestion, they're a requirement...
 

Neodym

macrumors 68000
Jul 5, 2002
1,942
519
Pretty sure this is why the heat sinks aren't a suggestion, they're a requirement...
Not really. In my 1,1 I had two sticks with "slim" heatsinks and two with half big / half small heatsinks for several years. Despite the temperature being around 70-80 Centigrades on the slim ones I got not one single hiccup, even when running full load for several consecutive days (and nights)!
 

Spacedust

macrumors 6502a
Original poster
May 24, 2009
934
91
Not really. In my 1,1 I had two sticks with "slim" heatsinks and two with half big / half small heatsinks for several years. Despite the temperature being around 70-80 Centigrades on the slim ones I got not one single hiccup, even when running full load for several consecutive days (and nights)!
If they can't work with small heatsinks then in 1U servers there should be fire ;)

I've added some additional copper heatsinks on a core of a FB-DIMM chip, but this dropped temps only a little bit.

It's time to start thinking about Mac Pro 2009 ;)
 

thekev

macrumors 604
Aug 5, 2010
6,720
1,820
If they can't work with small heatsinks then in 1U servers there should be fire ;)

I've added some additional copper heatsinks on a core of a FB-DIMM chip, but this dropped temps only a little bit.

It's time to start thinking about Mac Pro 2009 ;)
Servers are often much noisier. Given that you weren't using something that was certified, there's no way to guarantee that it will work. It shouldn't have taken 6 sticks to figure that out. As for the 2009, they fixed refurb pricing. In the US hex core machines have come up around $2450. You should understand that things are cooled differently in a rackmount server.
 

gpzjock

macrumors 6502a
May 4, 2009
798
33
I replaced my Apple RAM with Memory America modules that have the full size heat sinks. In 4 years of running at 80 degrees 2 modules have gone bad out of 8. In each case the vendor has replaced all 4 sticks from the set containing the bad module with 2 matched pairs at postage cost only.
Lifetime warranties FTW.
 

ColdCase

macrumors 68030
Feb 10, 2008
2,971
145
NH
I dunno, but I purchased several sticks from DMS back in 2008 with big honking heat sinks and have never had an issue. In fact I don't think I've had a problem with their certified stuff since I started buying memory from them in the 90s.
 

Snowshiro

macrumors 6502
Jan 12, 2008
384
4
The only memory modules I've ever had die (3 in total) are the "official" Apple ones that came with the Pro. The ones I've bought from OWC have been rock solid. A bit sad really that Apple couldn't have done better with their choice of manufacturer.
 

paulrbeers

macrumors 68040
Dec 17, 2009
3,960
120
If they can't work with small heatsinks then in 1U servers there should be fire ;)

I've added some additional copper heatsinks on a core of a FB-DIMM chip, but this dropped temps only a little bit.

It's time to start thinking about Mac Pro 2009 ;)
Umm, a server generally has large fans that push a lot of air thru them. The Mac Pros on the other hand are designed to sit next to a desk where noise from large fans are generally not tollerated. There's a big difference between servers and workstations. I know that seems crazy..... (or not)

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Not really. In my 1,1 I had two sticks with "slim" heatsinks and two with half big / half small heatsinks for several years. Despite the temperature being around 70-80 Centigrades on the slim ones I got not one single hiccup, even when running full load for several consecutive days (and nights)!
Also the 1,1 only uses 667mhz RAM and runs a lot cooler than the 800mhz Ram in the 3,1's. Also, it has been shown that for 512mb and 1GB sticks, the temperatures remain low enough that the slim heat sinks aren't as big of a deal but once you step up to 2GB and especially 4GB, they become even more necessary.
 

Neodym

macrumors 68000
Jul 5, 2002
1,942
519
I replaced my Apple RAM with Memory America modules that have the full size heat sinks. In 4 years of running at 80 degrees
Wow - 80 degrees with full-size heatsinks? I wonder what temperatures i could have achieved if i replaced that slims with the full-size heatsinks from my old 512MB modules...

Also the 1,1 only uses 667mhz RAM and runs a lot cooler than the 800mhz Ram in the 3,1's.
Not sure about that one. 800MHz is 20% more, granted - but i would expect the temperatures to only increase nonlinear, as the producers should have experience in fabrication after producing 667MHz for some time (thus better quality dies from the process) and therefore allowing for 800MHz in the first place. Depending on the module there might even have been a die-shrink somewhere along the way.

With a linear increase we would be talking about 80 degrees plus 20%, thus getting close to 100°C, which i can't believe to be tolerated by neither the producer nor the purchaser, as the failure rate would probably skyrocket on such modules.

Also, it has been shown that for 512mb and 1GB sticks, the temperatures remain low enough that the slim heat sinks aren't as big of a deal but once you step up to 2GB and especially 4GB, they become even more necessary.
Not according to my experiences: The slim heatsinks were sitting on the 4GB modules, whereas the 2GB modules had the half/half ones. And neither made any problems, despite the 78-80°C on the slim heatsink ones.
 

jickerson

macrumors newbie
Aug 18, 2012
13
0
Pretty sure this is why the heat sinks aren't a suggestion, they're a requirement...
Just curious (new to the "light" side of the force), but why are mac pro's so much more demanding on their RAM. I've built many a PC and always thought heatsinks on ram was just a gimmick, and never had any problems using non-heatsink sticks.
 

paulrbeers

macrumors 68040
Dec 17, 2009
3,960
120
Not according to my experiences: The slim heatsinks were sitting on the 4GB modules, whereas the 2GB modules had the half/half ones. And neither made any problems, despite the 78-80°C on the slim heatsink ones.
Here's some good information on user experiences using the slim heat sinks vs apple recommended....

http://www.xlr8yourmac.com/systems/mac_pro/mac_pro_ram.html

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Just curious (new to the "light" side of the force), but why are mac pro's so much more demanding on their RAM. I've built many a PC and always thought heatsinks on ram was just a gimmick, and never had any problems using non-heatsink sticks.
You've probably never built a PC with FBDIMMS which is what the 1,1 - 3,1 Mac Pros use. The ABM chip on them get super hot and requires a lot of cooling. Regularly unbuffered, non-ecc RAM wouldn't have an ABM chip and therefore requires limited cooling.
 

Spacedust

macrumors 6502a
Original poster
May 24, 2009
934
91
Just to let everyone now:

4Rx8 sticks does not work in Mac Pro 2008 :/ I have to return them, but the good news is I've used some compressed air on my Micron stick and BOOM it's fully working again ! It was just a lot of dust under the heatsink.

It passes all 8 tests in memtest with no errors...