Memory not Detected?

So I have a machine I built from old parts that I just stuck Redhat 9 on, and I'm running into a strange issue. At first I simply didn't have enough memory to run RH with the full GUI, and I sure as heck am not well enough versed in Linux to run a strictly command line installation. So I set the machine aside until I could get more memory...

...which is now. I purchased a 128mb SDRAM stick and stuck it in. I also have some older sticks, but I have no idea how much memory they have, as none of them are marked (I just know not a lot, 64mb each at most). I had an extra slot, so I also stuck in one of those sticks.

So I just brought the machine back online and installed a totally fresh RH 9 on it, GUI and all no problemo. However, it's running slow as Christmas. So then I see that according to system settings, it thinks it's only running on 64mb of RAM. I'm presuming that must be the old stick, but I have that new 128mb stick firmly placed in the first SDRAM slot.

So what could be the cause of this?

Swap memory in the slots, see what happens. (what memory shows up)
It's likely the mobo doesn't like that particular combination.

Also ensure you go into BIOS screen at reboot to see what BIOS is recognizing, despite what RH is telling you.

Now, being a Windows guy thus far, I have to ask this, as stupid a question it might be, but --

Does Linux automatically reconfigure around the hardware change when you alter memory?

Not being a real Linux guy YET, I'd say:

Linux queries BIOS for the total amount of memory.

*agree* ZT - Linux is the OS - it looks to BIOS for memory amounts and locations.

watch how you're mixing and matching that memory AK, that could be a problem. I'm curious if the older MoBo you're using supports 128 sticks? Also might be a bad slot - which swapping the sticks around will indicate clearly to you.

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...according to system settings...

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Do you mean from the BIOS or from within the OS with this
If the BIOS says this: make sure the memory speed can be handled by the systemboard (100 != 133)
Otherwise:

Have you tried passing the 'mem=192M' to the bootloader ?

If it works you might wannt to try 'man 5 lilo.conf' to pass it automaticly

Ok, got it figured out, and I'm writing this from a fully functional Redhat 9 box!

Turns out the old 64mb card would not work with the new 123mb card. I didn't think about it before, but I suppose it could be a difference in bus speeds or something. So now I'm running 128mb on this box.

However, despite running 128mb RAM, this box is SLOW. It's taking me forever just to go from one website to the next. Is Redhat THAT demanding on memory? Is 128 still not enough? I'm thinking I need to go up to at least 256mb?

Hi Angelic~

If you think RH is slow, try running WIN XP on it :D

Hey, I don't want to start any petty OS war here.............the "best" OS is one that YOU understand and that works for YOU. I have RH 5.2 and SuSE 6.x...............I am sure that they would work just fine...................

Way back when, all OSes were command line, and MAC and 'Doze were the first to develop GUIs as we know them. This was in an environment when 16Mb of RAM was a lot.

Recent linux distros have developed GUIs in leaps and bounds (OK Linspire is my only recent experience, but I am going to follow that tut by Gore and whack SuSE on my XP box :) )

These have been developed in the environment of Pentium/Athlon processors and at least 256Mb of PC100 or better. There is no incentive for the developers of Linux distros to build in any sort of backwards compatibility with old hardware..................Microsoft do have to think about that because of their huge customer base.

What I am suggesting is that you really need to be comparing your latest Linux with the latest Windows............

just my £0.02

Well done for getting the box up and running (albeit slow). Big rule of thumb for me when building boxes, most especially when reworking legacy boxes --- "You can NEVER have too much memory."

Load that bastitch up to the max it'll take.

Rule:.. dont mix PC100 with pc133 or PC66 with PC100 or Pc133
Rule: Dont mix Single sided with Double sided memory
Rule: on older MObo'only Double sided memory modules over 64Mb will work
Rule: Rules are made to be broken
Rule: When playing with Old MoBo.. a **** load of mixed ram modules helps in fault finding..( but be careful if mixxing in a machine)

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When playing with Old MoBo.. a **** load of mixed ram modules helps in fault finding..( but be careful if mixxing in a machine)

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Hi Undies, I have actually used the technique to violate a large corporate's BIOS/CMOS custom security :D

It would not let me replace a hardware device so I gave it a bit of a "shock" and it re-assessed itself, adding the new device...........yes...........I got it to accept a thumb drive as well :cool:

Errrr................nothing illegal, my mate's wife had got the machine from work when they were doing a hardware upgrade...........it just had custom BIOS that prevented new devices being added...........all I had to do was provoke it into looking at what was actually attached?

Cheers

Thanks guys. This has proven to be one of the more educational threads for me as of late.

I was expecting Redhat to at least run somewhat ok on 128mb because my impression thus had been that Linux was always an overall faster running OS, partly due to the fact that Linux folks are so sick of XP using up so much memory for nother reason than looking flashy. So that's why I was a little surprised when this box was still creeping. Anyway, I guess I should've expected as much since Redhat is one of the more "windowsish" distros (from what I understand anyway).

I eventually will be heeding gore's suggesting and rigging Slackware on one of these boxes...

So I hadn't thought of the differences between memory sticks, and I should have. For one thing, I have no way of telling bus speeds or even memory size on these older sticks because they're not marked, so I'm just kinda having to throw them in there and see what happens. So there is a way to mix unlike memory and get away with it eh?

Anyway, the input's been very helpful. I think I'm going to pull another 128mb out of a Win98 machine I have running over here and move it over to this Redhat one. That should help speed things up to an at least useable speed!

It's running great now! I put in that other 128mb stick so I now have 256mb, and it's running nice and smooth. VICTORY!!!! :D

Thanks guys!

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Rule: Rules are made to be broken

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The rules I give are general rules.. more as a fault finding guideline

Glad to hear things are working better


cheers

Yeh, motherboards have pretty strict rules that apply to the types of RAM that they can handle. Like for example, alot of mobo's that I'm seeing nowadays can take 2100, 2700, and 3200 Ram sticks, and have a max of 3 or 4 gigs, But have a maximum of 1 2700 or 3200 ram stick up to a gig. Weird stuff like that, and when your dealing with an older motherboard, your really kind of shooting in the dark...

So is there anyway to figure out what such stats are on a memory stick if it isn't marked with a label giving the info?

This site breaks it down for you

http://www.pcstats.com/articleview.cfm?articleID=179