08-28-2010, 06:12 AM
Physically, a DDR3 RAM fit's into a DDR2 slot, because they are usually the same sizes, but your motherboard has to support DDR3 in order to get it working. Also, it's not only about DDR (DDR2/DDR3), but about the frequency etc. If your motherboard / CPU can take RAM with only, let's say, 667MHz DDR2, a 800MHz DDR2 won't work properly inside it. This happened to me:
I have 2 older laptops, the older one supports DDR only, the newer one supports DDR2 too, but has currently DDR RAM inside.
So I tried to upgrade RAM in the older laptop (because it has a better CPU) by placing there one RAM from my newer laptop, which is also DDR.
I thought that they will work, but then I realised, that the 256MB RAM module is running on a different frequency than the 128MB one that was currently in. After turning on my laptop I saw tons of hexadecimal numbers.
I have 2 older laptops, the older one supports DDR only, the newer one supports DDR2 too, but has currently DDR RAM inside.
So I tried to upgrade RAM in the older laptop (because it has a better CPU) by placing there one RAM from my newer laptop, which is also DDR.
I thought that they will work, but then I realised, that the 256MB RAM module is running on a different frequency than the 128MB one that was currently in. After turning on my laptop I saw tons of hexadecimal numbers.