Laptop Inspiron 6400/E1505 - Memory Upgrade Question

2G max as 2X1 G soDIMMs.

is this "Kingston 1024MB PC4200 DDR2 533MHz SODIMM Memory" compatible with my system?

my current Memory has the following data on it: DDR2 512 2Rx16 PC2 4200S-444-12-A0

let me see if I got it right: that means that I can only buy a 1GB extra memory and keep my current 512mb (or buy 2x 1GB DDR2)?

I won't be able to use 1x2gb memory on my laptop...

did I understand it correctly?

It's not absolutely required, but you will lose some performance with single soDIMMs or mismatched soDIMMs.  You very likely have 2X256 now.

It's not absolutely required, but you will lose some performance with single soDIMMs or mismatched soDIMMs.  You very likely have 2X256 now.

I have 1x512MB... I opened it up to check out what I had before I went buying something that was not correct for my Laptop...

THIS IS THE DATA ON MY MEMORY -> DDR2 512 2Rx16 PC2 4200S-444-12-A0

There may actually be a difference between the 6400 and the E1505, but I can tell you that I am currently running 4 GB of RAM in my E1505 without any problems. All of the memory is addressable in Windows 7 64bit, and everything works great. I find it odd because the user manual says it is limited to 2GB of RAM, but that obviously isn't the case. Perhaps it was a BIOS update after the initial release that added support for more memory. My E1505 has the T7200 Core2 Duo, but it is possible that there may be a memory limitation on the 6400's due to them using the older processor models.

As for memory choices, any DDR2 SODIMM will work in your laptop. The speed will not matter much as Dell often locks the memory speed to match the FSB of the processor (unless the memory is slower than the CPU). I went with PC5300 in my machine, and they have been running just fine with no heat issues or performance problems. Dual channel really isn't that significant of a difference, and having two sticks will actually use a tiny bit more power (though it isn't really noticeable).

There may actually be a difference between the 6400 and the E1505, but I can tell you that I am currently running 4 GB of RAM in my E1505 without any problems. All of the memory is addressable in Windows 7 64bit, and everything works great. I find it odd because the user manual says it is limited to 2GB of RAM, but that obviously isn't the case. Perhaps it was a BIOS update after the initial release that added support for more memory. My E1505 has the T7200 Core2 Duo, but it is possible that there may be a memory limitation on the 6400's due to them using the older processor models. As for memory choices, any DDR2 SODIMM will work in your laptop. The speed will not matter much as Dell often locks the memory speed to match the FSB of the processor (unless the memory is slower than the CPU). I went with PC5300 in my machine, and they have been running just fine with no heat issues or performance problems. Dual channel really isn't that significant of a difference, and having two sticks will actually use a tiny bit more power (though it isn't really noticeable).

you just made my day... I will get that 1GB memory... that means I will have 3x more memory than what I currently have... thou having 5 times more would be a much better option... LOL

I also have Inpiron 6400 with WIN7 32bit on it. I used to have 2x512MB 667 MHZ RAM (Samsung 512MB 2Rx 16 PC2-5300S). Yesterday I bought a 2GB 667 MHZ RAM (PC2-5300 CL5). Firts I took the old RAM out of my laptom, and put in the 2GB RAM. It worked fine. Today I put in one of the former 512MB RAM too, and they work together well without deceleration.

Accordint to my description of laptop, the maximum memory is 2GB. I made BIOS upgrade sometime. Maybe it causes that I can use 2.5GB memory.

I have 1.73 GHz Dual-Core (32-bit) processor.

Same thing for my I am using 2 GB and 512 MB in other slot... and its working fine, now I am thinking to buy one more of 2 GB...lets see....how it works.....I have same ispiron 6400

So frustrated that for years I have wanted to increase the RAM  from 2x1gb on my 6400 and have constantly got told by "tech experts" including dell them selves that 2GB is the max Ram... Which is B.S. Have been running 2x2gb DDR2 with no problems for the last  2 mths...  And yes it only utilizes 3.2 Gb, this still HAS lead to a dramatic increase in speed and performance GRRRRRRRR!!!!!!!!  Have also heard that changing from vista to windows 7 allows the 6400 to recognise even more of the 4gb but havnt had the chance to try this one out for my self...

you can go to 3 gb on 32 4 on 64