The advice to use certain metal is due to materials reacting with each other and corroding. So you want SIMM slots and modules to be using the same metal.

Silver is a bit more conductive than gold, but gold makes contacts more wear resistant, which is more important than conductivity for this type of use.

Silver? Do you mean tin?

You are right. I meant "silver" as colour + which is in fact tin plated.

Gold does not oxidize, but that's it. It makes no difference whatsoever. No memory module ever failed because it had no gold-plated contacts.

There was an advice back then to avoid mixing gold and tin (such as using tin plated modules on gold plated contacts) as it could be a cause of corrosion/oxidization. But I have never seen any noticeable effect on boards/modules that had this type of mix for several years, so even if there is some type of corrosion it's probably not enough to be a problem.

I have been doing this stuff for decades and have also never witnessed any ill effects from mating tin and gold contacts.

Never experienced that either I think. But I can't tell as I don't routinely measure capacitance and resistance of my contacts 😀

But fretting is a well-researched topic and unless you have some extreme case (or measure in lab) you don't know if a memory error was caused by this or something else.

gold to gold contacts is a gold standard 😀

You will never see Silver used on normal consumer products, only aerospace or military. The reason they use silver is to eliminate tin splinters that form under vibration. There is no capacitance advantage, all lands are copper base and then plated with tin, nickle or gold.

Swiego wrote on 2020-05-24, 16:06:

I often see advice when troubleshooting to make sure one is using simms or dimms that are gold plated.

on the other hand, in all of the intel socket4-7 mainboard manuals it's specifically mentioned to only use tin leaded SIMMs, for whatever that's worth.

maxtherabbit wrote on 2020-05-24, 17:28:

I have been doing this stuff for decades and have also never witnessed any ill effects from mating tin and gold contacts.

Nor have I......

Gold contacts are harder and have a lower oxidation. Tin contacts tending to cold welding, depending on force and friction. The advantage of gold depends on intended purpose.

You take gold if:
- frequent plugging
- vibration in the connection
- corrosive environment
- low voltage and current over the connection

Applied to the use case for RAM modules it should make no difference. Maybe in case of corrosion, if you don’t run your system for many years ... or if you often mount and dismount the module.