RAM mix and match

[Wolf52]

Is it acceptable to use different types of ram in the same computer as long as they are compatible with the motherboard? The reason why i ask is because I am about to buy a new motherboard, and i want to reuse some of the ram from my old board (~3 years old now). If it is acceptable, would adding more ram actually hinder my overall performance or is more simply better?

 

[aimeeandbeatles]

Google is your friend.

 

[Aramazd]

You can't put DDR2 and DDR3 on the same mobo together, but you could put DDR2-800 and DDR2-667, although the speed will be determined by the slower one and you could place RAM from 2 different manufacturers together.

Google is your friend.

Unlike most of your stuff, I think this is a valid question.

 

[Wolf52]

That was the general idea i had, you could swap a little if it was just a bit of a speed difference. I'm mostly trying to cut costs on my new system and i was hoping to hold some over from my older (current) setup. At least ram is relatively cheap these days...

 

[Genocidicbunny]

Can it be done? Yes
Is it a good idea? No
Will it work always? Definite No.
Basically, its trial and error if its going to work together. The best scenario would be if they have the same speed, voltage and CAS. Voltage I would say is one of the more important, because if one set of modules doesnt run at one voltage, and needs a higher one, and the other set burns out at the higher voltage, you have a problem. CAS can always be synced to the slower one, same with speed.
My personal experience with this has been pretty bad. I wasnt able to get two sets of RAM with identical voltage, CAS and speed to work together, even by lowering the speed down to 800mHz and CAS to 6 ( DDR2 memory so)
YMMV

 

[GoodGame]

My personal experience agrees with G-bunny's response. It'll only work if they're all the same DDR versions (all DDR1, DDR2, or DDR3).

Even then, you can try it, but getting the BIOS settings (timings and voltages especially) just right for a diverse bunch of RAM is kind of tricky, and only fleetingly successful. I had a pair that I had to reset the BIOS all the time to get them to work together. If you do try it, best to get all rated for the same speed from the same maker. And if you use a CPU/mobo with cache support (e.g. L2) best to get a pair in the exact same denominations in the first two slots. If you have 4 total RAM slots, you can try using your old RAM in them, but I wouldn't do that unless they were spec'd for a fast speed.

 

[Genocidicbunny]

My personal experience agrees with G-bunny's response. It'll only work if they're all the same DDR versions (all DDR1, DDR2, or DDR3).

Even then, you can try it, but getting the BIOS settings (timings and voltages especially) just right for a diverse bunch of RAM is kind of tricky, and only fleetingly successful. I had a pair that I had to reset the BIOS all the time to get them to work together. If you do try it, best to get all rated for the same speed from the same maker. And if you use a CPU/mobo with cache support (e.g. L2) best to get a pair in the exact same denominations in the first two slots. If you have 4 total RAM slots, you can try using your old RAM in them, but I wouldn't do that unless they were spec'd for a fast speed.

Indeed.
My suggestion is that if you're sure your current RAm is 100% good, take it, save it, get some new faster RAM. I had to go through 3 sets before I got one that worked/did not get fried by the motherboard. In such a case, it is handy to have a backup set that you know is working, to both troubleshoot and use when your new RAM is getting RMA'd ( if its getting RMA'd that is).

As for brands, my personal experience has been the best with Corsair. Ive had RAM from them since my first 'my own' computer, a P3 machine. Their tech support has been good, and their Ask The Ram Guy forum is pretty good about answering questions fast. You can also, if your set breaks, ask them that before they send you a new one, to test it thoroughly. They've done this for me for free.

 

[GoodGame]

I should add to be sure they're all recommended for the same voltage, especially. That seems to cause the most problems, and leads to memory/file copy errors/need to reset BIOS settings.

For instance most RAM are @ 1.8V, but some are 2.1V, etc... I believe RAM are very voltage sensitive.

 

[Genocidicbunny]

RAM can be extremely voltage sensetive, but it really depends. Some DDR2 1066 modules are just DDR2 800 ones OC'd to reach 1066 and have voltage added to stabilize them. These modules are likely to be quite unstable at 1.8v, but work fine at 2.1v
Still, voltage matching is what I would look for the most. You can always downgrade speed and CAS to the lowest common factor, but upping voltage on a set not meant for it could fry the set, and lowering it on another could make it unstable.

 

[aimeeandbeatles]

The RAM in my old computer was voltage-sensitive. They finally figured out why it died -- a power surge fried the RAM.

 

[Genocidicbunny]

That doesnt mean its voltage sensitive in the way we're talking about. A power surge could potentially take out any component. Because all components in a computer are sensitive to high voltages. ( Its why static electricity can fry a computer. The voltage spike is somewhere in the thousands)

 

[aimeeandbeatles]

Well, we didn't even notice the surge, it was so small. (We have messed up electrical system.)

 

[GoodGame]

We were talking about the RAM voltage setting in the BIOS. Some RAM seem very sensitive to under/over voltage, so a pair of mis-matched RAM may never get stable on any voltage setting.

 

[aimeeandbeatles]

ok, sorry I misunderstood.