OVerclocking difference between 2 X 256, and 2 X 512 sticks of RAM?

I've been lead to believe that, generally, 2 X 256 Megabyte sticks of RAM will overclock much better than 2 X 512 Megabyte sticks of RAM with the same chips.

Is this always the case?

Typically, how big a difference is it?

Example: Is it possible to hit the same speeds with 2 X 512 megs of RAM, as it is with 2 X 256 megs of RAM, using the same timings, and voltage?

If not, why?

I've heard something similar when it comes to using two sticks. I've always had good luck clocking using just one stick. (ie one 512 or one 1024). One stick will clock better than two.

^I've heard the same.

I think it goes sth like this
1 stick OC'd > 2 sticks OC'd > 2 sticks in dual channel OC'd

Can't say I know from first hand experience but that's the general impression I've gotten. Mind you I'm still using 2 sticks in DC as I believe the increase from DC is greater then the couple mhz you lose from the OC. This would be especially true for a 64-bit system.

I also think I read that single sided sticks (256mb) will clock higher then 2 sided sticks (512mb) but I'm pretty sketchy on that...

Another very related thing that I'm wondering, is why so many of the top 3DMark benchers use only a half gigabyte of RAM, in 2 X 256 Megabyte sticks?

Why not just use a full gigabyte in 2 X 512 Megabyte sticks?

I've seen 1024 meg sets of BH-5 perform well enough to match the FSB of many 512 meg BH-5 sets that these guys are using, so what's up?

I have another question also. I've been reading that memory slots used most of the time are slots 1 & 3. I'm searching for the post on why 2x256 o/c's better than 2x512. In the same post someone also stated that you could run in slot 1/256mb, slot 3/256 mb and run in slot 2/512 in total 1 gig of ram and still overclock? Is this true?

Thanks

mixing mem size is never a good idea(it can work,but in some cases it lowers your max fsb,or your system gets totally unstable even on stock-this is at least on nforce 2 mobos...)
2x256 mb will give you some more fsb than 2x512 mb-its like t_dub said because of the 512 mb sticks beeing double sided.

Because with a gig it undervolts more than it would with only 512, so you're getting more voltage whether you are aware of it or not - and can therefore clock higher if using decent parts. I Could clock higher on 512, had to get the OCZ Volt booster to get to 300fsb 1:1 w/ 1gig

the main reason for this at least on Nforce boards is because of the memory controllers.... basically the doublesided ram gives the memory controllers a hard time, so if only one side of ram is being worked, generally the memory controllers maintain higher frequencies. Introduce another side to the ram and the controllers have to work that much harder...... not the most scientific explaination but i think that kinda covers it some.....