RAM upgrade on Dell Dimension 5000
 

Hi,

in my spare time I'm helping people switch from Windows (mostly XP) to Linux. In this case, I'm helping a guy with a quite dated Dell Dimension 5000. The PC is using a single slot with 2GB memory (Samsung m378t5663qz3-cf7). Accoding to the Dell manual this PC supports 400- and 533-MHz DDR2 unbuffered SDRAM, with 256 MB, 512 MB, or 1 GB non-ECC capacity and mounts max 4 GB.

How is it possible that a single module of 2GB (800MHz) works?

I'd recommended this guy to switch to 4 x 1 GB, i.e. upgrading his machine to 4 GB, he saw also the manual, but he said he'd like to try adding another 2 GB of the above Samsung.

Should he do so or stick to the manual recommendations?

Thanks!

I found a similar unanswered question and when the OP added a 2nd 2G module the computer would frequently crash. Maybe bad memory... I don't know how it works either since your supposed to install DDR2 in pairs. I also would take the conservative side and install 4X1 GB memory modules.

http://en.community.dell.com/support...514/t/19470138

BIOS and Linux Kernel capacities
 

Hi. It is very interisting topic.
Years ago i read that linux can recognize and use hds bigger than BIOS supporting. This is because the OS read the first sectors (up to BIOS limit), but when Kernel began to work it can read all the disk because it was 32 bits (of course it is year 2000 news).
May be the same case, reading BIOS with the RAM?
It was an interesting knowledge but i cant read about.

Have a nice day.

I would look into the bios settings to see how that RAM is configured. Usually you can see the speed settings and often change them in bios. It may be the bios has been upgraded from the default which is what the manual says is supported. The fact he is able to use a single dimm marked as ddr2 800 and the manual calls for 400 or 533 is not really surprising since most ram can be used at less than its maximum rated speed. The manual says supported but that often is not the only things that will work. Other configs are merely 'unsupported' even if they work fine.

It also is quite common for ram to be used single channel (one dimm) or dual channel (2 or 4 dimms) and it seems his is running single channel.

If you add memory it should be matched pairs and properly inserted for dual channel operation. I would suspect that it will be difficult to get a new dimm matching what is installed due to age so it would depend upon what he wishes for maximum how it should be arranged. I would, however, stress that if he wishes to upgrade that he either go with 4 1G dimms as has already been suggested, or 2 new matched 2G dimms as near as possible to what is already there as can be found.

Make sure he understands that if he tries using memory that is not supported that it may or may not work. Also let him know that running the same amount of memory in dual channel mode is often faster than single channel operation.

IME, the DDR2 speed difference according to memtest86+ varies between single channel speed a bit more than half of dual channel speed, and single channel speed around 70% of dual channel speed, quite a difference in every case.