incompatible RAM

[A Silver]

I upgraded my dads pc and replaced the old RAM with some new RAM (2x1gb DDR3 to 2x2gb DDR3) an everything is fine but i wanted to put the old ram into my new PC but i'm worried it may not be compatible and may be slower than the current ram i have installed and would that slow it down?. If the ram is not compatible will it just not show up or will it damage my PC and can i even put two different types of RAM in my pc?

 

UPDATE: Even though my PC uses DDR3 RAM it was impossible to install it. I'm convinced it is DDR3 ram as the replacement RAM for the old PC  it came from was DDR3 and it fitted with no issues.

[bgibbz]

If it isnt compatible, it won't fit the slot. 

[Electronics Wizardy]

What ram do you have?

 

Just chuck in and see, but 2 gigs isn't much, you can get 16 for about 80 now.

[A Silver]

Just now, Electronics Wizardy said:

What ram do you have?

 

Just chuck in and see, but 2 gigs isn't much, you can get 16 for about 80 now.

I have 16GB of hyper x fury and i felt like recycling the ram as i have no other use for it and my pc has two empty slots.

[Electronics Wizardy]

Just now, A Silver said:

I have 16GB of hyper x fury and i felt like recycling the ram as i have no other use for it and my pc has two empty slots.

Id then keep that ram for testing. The extra won't help much at all.

[A Silver]

1 minute ago, Electronics Wizardy said:

Id then keep that ram for testing. The extra won't help much at all.

Ok. I may put it in anyway just to see if it works

[Whitemk2]

Chances are if its from an older system it probably runs at lower frequencies than the other things you already have. I'd do as others say and just keep it as a backup or to help troubleshoot issues.