Can a motherboard have more than one RAM?

Answer 1

To answer your question, let's make something clear: there can be four different things meant when you ask about "different types":

1. Different technologies: for instance, SDR (Single Data Rate), DDR (Double Data Rate), DDR2 (2nd Generation Double Data Rate), etc.
2. Different speeds: within a given technologies, the RAM can be built to run at different speeds: 800Mhz, 1066Mhz, 1333Mhz, etc.
3. Different features: RAM designs have a bunch of other properties, depending on their target audience. Things like ECC (Error Correction), being buffered or unbuffered, are the major extra features.
4. Different hardware: even if two pieces of RAM have #1 - #3 all the same, it is possible to construct the RAM itself from a variety of different physical chips. For instance, a 1Gbyte RAM module can be made using 8 x 1Gbit chips, or 4 x 2Gbit chips, or 2 x 4Gbit chips.

The short answer to this question (which will satisfy 99% of all computers), is that a computer can use only a single technology and feature set, can use speeds equal to or GREATER than your existing RAM, and can normally use different hardware designs within that technology and feature set.

For instance, the vast majority of systems which are sold as "desktops" (NOT workstations or servers), use a single type of SDR, DDR, DDR2, or DDR3 RAM (these days, it's DDR3, with DDR2 common for machines made in the last 5 years), with the feature set of NO ECC, and NO buffering ("unbuffered"). Very, very briefly around 2000-01, there were some of systems made that had BOTH SDR and DDR sockets - however, only ONE of those two sets of RAM sockets could be used at once, so it wasn't possible to use DDR and SDR RAM at the same time. Systems can use any speed of RAM, but will run at the LOWEST speed of any DIMM used - so, if you have a mix of 800Mhz and 1333Mhz DIMMs, the system runs at 800Mhz.

Please check your motherboard or system documentation. It will explicitly lay out the combinations of the four factors above that can be used in your system. If your motherboard manual doesn't explicitly say it can be used, then DON'T assume it works. If you are unsure, ask your local computer repair store - they'll know for certain.

Answer 2

You can only put different types (SDR_SDRAM, DDR, DDR2, DDR3, etc...) in your computer if your motherboard supports the slots needed for them. Generally, if you have two types installed, one type will not be usable. You can use RAM modules of different speeds, as long as your Front Side Bus can run at the speed of the lowest module you put in. You can use different brands and capacities of RAM on your motherboard without any real issues.

Answer 3

At the time of writing, there are several types of RAM, which are quite different. This means that they normally cannot be used on the same motherboard - they are not compatible.

Answer 4

Yes. Depending on the type (and age) of the motherboard - RAM is either installed as single chips - or 'matched pairs'.