RAM supply voltage.

[St. Augustine]

Ok I have quite a simple question I should imagine but all the same it is one to which I have not been able to find an answer. Does the supply voltage of RAM actually affect either performance or compatability? For instance would it be possible to have memory modules of two different supply voltages running on the same motherboard? I've never tried this before as I always tend to go for exact matches but have realised doing so I could save myself some money.

[Erik]

Does the supply voltage of RAM actually affect either performance or compatability?

You mean the stock (ie: factory default) voltage?
Yes, they affects both performance and compatibility.

DDR2 operates standard at 1.8V

When a module has a stock voltage higher than 1.8V it basically means it's factory over-clocked and couldn't reach the rates speeds with normal voltages.
These modules can usually not be over-clocked as high as modules which are rated for the same speed, but at 1.8V

RAM with higher stock voltages can also cause compatibility issues with some motherboards.
And I don't think it's possible to set different voltages for different modules.

[King Edward I]

its theoretically possible to do it but very hard to work out - you could overvolt some ram and undervolt th other but it gives rise to a lot of stability provblems and can burn out ram etc.

my ram is rated @ 2.2V @ 1066 Cas 5, but I run it @ 1000 4-4-4-10 @ 2.1-2.15V, so if you took time you could get it to work but its probably not worth the hassle

[St. Augustine]

Thanks guys, with that in mind I think I'll take the easy option & just go for matching modules. It certainly does sound like a lot of bother otherwise.