Originally Posted by DuckieHo
Actually, heatspreader ARE useful on most RAM now. It is quite possible for chips to break contacts due to thermal cycling. The heatspreader helps even out chip temperatures. RAM chips are now the surface mount type which can fail as opposed to the older RAM where contacts where around the edges only.
I'm pretty skeptical that thermal cycling would break BGA solder contacts at the even at the temperature range my memory runs at (~25-70C). There are safeguards inplace to prevent this, and the official, warranteed, operating temperatures for most memory ICs are fairly huge (on the order of 0C to 85C).
You do have a point about heatspreaders evening out temps/reducing hot spots. This does make the memory easier to cool with active air flow. Even if air flow is not perfect over the whole module, all the ICs still see a benefit.
Even in a case with very good air flow, my memory routinely reaches temps that can burn skin (at DDR-1200, 2.3-2.35v), unless I have a fan sitting directly on them (then they only get luke warm).
I'm a habitual stress tester. If I've had parts for a week, they have probably been running at max load for at least 100 hours, and probably a lot more.Edited by Blameless - 8/23/08 at 4:21am