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Couldn't find any similar questions, so here it is.

I currently have 2GB of RAM in my PC, and I ordered a 4GB module a few days ago. I run Win7 32-bit, so I know I can't use all 6GB of that total RAM. However, my question is: Would using both modules be faster than using just the 4GB one? Would the fact that they are not the same type of modules cause significant slowdown?


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Firstly, a 32 bit system can only address just over 3GB of RAM, so installing 6GB is a waste anyway.

Secondly, the only way that you can reach the 3GB limit of 32 bit without wasting a module is to use the single 4GB module.

Lastly, if you are to use multiple memory modules, they should be of the same clock speed. Some motherboards don't actually support single 4GB modules in one DIMM. You should check your motherboards specifications for this.

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The fastest option would have been to order a 2GB stick that exactly matches the 2GB stick you already have. Then your motherboard would likely be able to use dual channel mode so that not only do you (almost) double your existing RAM to bring it up to the max supported by your operating system, but the RAM now runs twice as fast. If it's not too late to return or cancel the 4GB order for a 2GB stick that matches what you have (or a new pair of 2GB sticks), I would strongly advise it.

If you absolutely cannot get to dual channel mode, than you should just install the 4GB stick and remove the 2GB entirely - you'll be able to use just as much RAM that is just as fast without the 2GB stick in the system, and removing it will save you a little bit of electricity (heat) and allow you to sell it on eBay or use it elsewhere.

A additional point: starting with Windows 7, Microsoft doesn't distinguish between a 32bit license and a 64bit license. This means you already have a 64bit license and lack only install media to be able to use it. (Note that you still have just one license total, but that the license can be applied to either a 64bit or 32bit system). Your computer manufacturer may be able to supply you with 64bit media for a very reasonable fee (as low as $10). It's probably a little more than that, but if it's too late to change your order, it's worth checking into whether you can effectively get a 2GB+ RAM upgrade for $10.

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Just remember that 'upgrading' from Win 32-bit to 64-bit means a complete reinstall of everything from scratch! – Linker3000 Jan 5 '11 at 20:47
@linker: in other words, you can't upgrade 32 bit to 64 bit :) – horatio Jan 5 '11 at 21:56

Your computer will be unable to use the extra 2GB as you said. The way RAM works with other chips is to use the slowest module's speed. If the 2GB chips is slower then the 4GB, you should remove it.

Check out: for more info!

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There won't be any slowdown, since you just have a 2 GiB module right now, so you aren't using dual/triple channel, which improves performance if same modules are used.

As for increased performance, I don't think you'll be getting anything if you're only using 32bit 7. If you remove the 2 GiB module, you'll save some power.

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