Motherboards and RAM questions

[prism]

I've been looking at some board now for the current 754 A64s, and noticed that lots of people use 3500 and up RAM with these boards, all of which say they support up to PC400 (3200). Is faster RAM still useable on these boards, but the extra speed just not activated unless stuff is overclocked? And does anyone know what speed of RAM the new 939 mobos will support? And I imagine they'll still be fine with non-ECC, non-registered, right?

Thanks for any information.

 

[mechBgon]

Overclocking headroom and perhaps an increase in stability at stock speed (although decent-quality PC3200 should be fine at stock speed too). 939 will use unbuffered non-ECC and probably will work with unbuffered ECC too.

 

[Pauli]

Here's what you have to realize about RAM speed ratings: the rating is the speed that it can run at, not what it runs at automatically. The RAM sticks do not have a clock on them -- it's the Motherboard settings that determine what speed the RAM is running. The fact that the RAM is rated higher has no effect on what speed it runs. If you are running PC2700 RAM in your system and you simply replace the stick(s) with PC4000 sticks, THE RAM WILL NOT BE RUNNING ANY FASTER! (Well, it is possible that the MB will autodetect the RAM timings to be different and change them -- this won't improve performance very much.)

There is so much misunderstanding about RAM around here, I hope this clears a few things up...

 

[prism]

So you mean the jump from PC2700 to PC4000 wouldn't make any difference, unless say the mobo could go up to 3200, then it would go up to 3200, right?

 

[Pauli]

Right.

 

[prism]

So it's pointless to go above PC3200 on 90% of today's mobos unless you're overclocking?