Hi
My motherboard is ASUS P5LD2-VM, Celeron 3.04Ghz and 512 RAM
Debian Sarge - Kernel 2.4 and Slackware 10.2 Kernel 2.6

Yesterday I bought another 1Gig ddr2 dimm memory (as instructed in the motherboard's manual)

To be honest with you, I can't see any difference
How can I check if this new memory is recognised by the system? Obviously, some part of the memory will be taken by graphics (on board-card), I also have swap space

When I issued the command: free -m

I couldn't understand it, I mean my ram is 'physical memory' which was something like 889MB. It doesn't make sense. It should be sth like 1350- 1500 MB.

On my motherboard there are two channels. each channel
has 2 ddr2 dimm sockets. I added the new memory to the same socket as the old 512MB, then I put it to the other channel, doesn't make any difference.

I know that Celeron is not one of the fastest processors,
but I expected everything to run visibly faster with 1.5Gb ram.

So to sum up:
1.how can I check whether the two memory modules (512+1024) are recognised and utilised by the system)
2.Where is the best place to put the second module (channel A - so togheter with the old memory or Channel B )The memory modules are not of the same vendor)
3. How else can I tune the performance of the computer


Thank you

No doubt your memory is fine but you must enable HIGHMEM(greater than 4GB) in your kernel. Once you do that, you should reboot and you will see the extra memory.And yes, 1GB more of Ram should speed things up quite a bit!!
Cheers!

<<Samoth>>

thanks, how can I do it in Debian or Slacware?

I was going to say search your packages for a kernel image to install but I checked and it looks like you will need to compile your own kernel unless that processor has dual core then you could install a -smp kernel and get the HIGHMEM support by default here is a guide to doing it the Debian way for Slackware I have no clue how they do it.

sycamorex

I am a little unclear about something. How many dimms do you have installed. If you have 1 512 and 1 1g, that will explain your problem. Generally you have to add dimms in sized pairs in order to see memory speed increases. 2 512 dimms will run faster than 1 1gb dimm. Mixing memory sizes in a channel or not saturating a channel (less than 2 dimms per channel) will lead to slow downs. These are all hardware issues and they will apply no matter what os you are running.

Linux handles memory much better than windows. If your are running only 2 or 3 "normal" programs you will not see much improvement in speed by going over 512. If you are using memory intensive programs (gimp) or more than 3 programs you will see some improvement.

With a lot of systems today the limiting factor is hard drive transfer speed rather than cpu (excluding cpu intensive tasks like video conversion). Look at the manpages of hardparm. It gives a description of how to test drive speeds.

Good Luck
Lazlow

thanks guys,

Yes I have 512 + 1024 - does that mean that the best option for me
is to buy another 512 to have 512+512 in one channel and 1024 in the second channel, or to buy another 1024 and have 1024 in each channel (and get rid of 512)?

thanks

Do you mean in the dual channel slots if so those modules should be purchased as a pair for using dual channel option so you should purchase matched pair for that. What you really should do now is go and download the Memtest86 program burn the bootable CD or make the boot floppy then boot with these and check that your ram will work together not in dual channel mode without errors, let the program run for a couple of passes probably going to take at least half to an hours time. Now even if you get errors off the start you should put in the ram sticks individually go into the BIOS and in your memory setting use the set to SPD option and write down the numbers it shows for each stick then go in and set the timings manually to highest values and run test again with both sticks of ram at these settings.

thanks, Can you please clarify a few things for me, please?

1. I burn the bootable cd and boot the computer with 2 memory sticks in ONE channel
and check if they can work together.

2. Then if I don't get errors, I guess it's ok
3. If I do get errors, shall I put each memory stick in a different channel
and do the same test, or leave the memory sticks in one channel and go to Bios to check the numbers?

4. Sorry, but I have never had anything to do with expanding my memory.
What exactly shall check in BIOS? First I set to SPD option and write down the numbers that will appear. (I am at work now so I can't check it now)

5. where can I set the timings manually to highest values?



Sorry, I am still a newbie

thanks for help and patience

First of all is both the RAM of the same speed, u cant have one running at 333 Mz and another at 400 Mz

In single channel configuration from looking at a picture of board on the web I would say one stick in the yellow and one in black slots.
Exactly the sticks are working fine together then.
Changing the slots probably won't matter for errors and you only have two choices anyways one in yellow slot one in black for single channel. Although I guess you could go first yellow then one each black and second yellow one time each black again.

In the BIOS there is usually three choices in the memory section AUTO, By SPD and Manual using the last two you will see a bunch of numbers show up these are the memory timings. Memory modules have different timings they will run at correctly and trying to mix modules that run at different timings can be difficult to make work sometimes depending on the motherboard/BIOS version on the board. The important part to get it to work correctly together is setting to use the higher of the two sticks timings ram will usually always run with loser (higher numbers lower performance) timing settings.
In the memory section of the BIOS using the Manual settings there is really only 4 settings that you should need to change if necessary (run the MEMTEST first to make sure you have problems) then even you probably won't need to actually change them when looking at each stick booted on its own using the By SPD option change to the Manual setting with the higher of the two in there and these will be used for the timings for both sticks when used together giving them the identical higher timings.

Your welcome. You may want to look at a couple of overclocking guides on the net to get an idea of what memory timings are, how they are set even if not overclocking it will give you some understanding of what is involved in changing them.

Hi all
I put both memory sticks in one channel and ran memtest86 for around 5 hours - 12 passes, 0 errors

So what am I supposed to do next?

I don't know if they run at the same frequency, the following info is written on the labels (on the memory sticks)


512mb memory:

Elixir M2U51264TU88AOB-3C
512MB 1Rx8
PC2-5300U-555-12-AI
0540M205A0400C A10080-1.XX.CN


and 1Gb stick:

NCP NC00735
DDR1GB
PC2 4300


thanks

Looks like they would be running at PC2 4300 speed (two sticks different speed run at the slowest of the two usually) and at least 5-5-5-12 for the timings from what you post above Google yields nothing for "NCP NC00735" so that is the best I can tell you there. Now that you know they work together without error it is time to compile your own kernel with the HIGHMEM support enabled then install and boot with it to get full use of the ram.

thanks, now I need to read about recompiling the kernel