Thinkpad X20 : What's the maximum memory useable ?

[WarMachine]

Hello ,

I'm going to buy an X20 with PIII-600.

The buyer says that the laptop has 128 MB soldered onto the mobo, and that he added a 256 MB memory stick.

128 + 256 = 384 MB.

When I look at this :

ftp://ftp.software.ibm.com/pc/pccbbs/mo ... serref.pdf

I see that the X20 can have 64 or 128 MB soldered on the mobo, but the max indicated is 320 MB.

If the laptop contains 128 MB on the mobo, it should max out to 384 MB, no ?

I have always tought 320 MB was the max for X20.

Are there models that could accept 384 MB ?

Thanks !

W.

[pianowizard]

The X20 has "64MB or 128MB standard", and "64MB on systemboard", which means when IBM sold the X20, they either left the second memory slot empty and put 64MB in it. All X20 models have 64MB soldered on the mobo.

[WarMachine]

Mmmmmh, OK !

So, I was right : The max is always 320 MB.

Thx for your answer !

W.

[WarMachine]

Hello,

The person who sells me the laptop had a look again.

Well, there are, indeed, 320 MB of RAM in the machine.

Everything is OK now.

I love when I'm right !

W.

[icebag]

The X20 has "64MB or 128MB standard", and "64MB on systemboard", which means when IBM sold the X20, they either left the second memory slot empty and put 64MB in it. All X20 models have 64MB soldered on the mobo.

That's what I thought, too, but ...

I just got today an X20 (2662-37G, 700 MHz) with 128 Mb on the mobo. It accepts another 128 in the slot. I don't have a 256 to try, but according to the documentation that ought *not* to work. I will get one and find out. It would be odd if IBM had released a model with higher in-built memory but lower max.

[icebag]

Another thing about my "new" X20. It recognises 256 (see above) when on AC power but sometimes only 128 on battery power. Not enough power getting to the memory slot?

[pianowizard]

That's what I thought, too, but ...

I just got today an X20 (2662-37G, 700 MHz) with 128 Mb on the mobo.

The X20 had either 600MHz PIII or 500MHz Celeron. It sounds like your "X20" has a motherboard from an X21. Some X21's had 128MB onboard RAM.

[icebag]

Yes, I wondered about that. How could I find out? And if it is an X21 motherboard will it recognise 256 in the memory slot?

[icebag]

And if it is an X21 motherboard will it recognise 256 in the memory slot?

According to crucial.com an X21 with 128 built in will see 384.

[pianowizard]

Yes, I wondered about that. How could I find out? And if it is an X21 motherboard will it recognise 256 in the memory slot?

Go to the BIOS. There should be a "System-unit serial number", of which the first 7 characters correspond to the mobo's product number.

An X21 mobo can recognize a low-density 256MB PC100 module in addition to the onboard RAM. How many chips are there on your 256MB stick? You want 8 chips on both sides, i.e. 16 chips total.

[icebag]

Got it. The BIOS shows 2662-64G which is, indeed, an X21. Excellent! Now to get my hands on a low density 256.

Thanks, pianowizard, for your help.

[WarMachine]

Hello,

When you perform a little search on IBM, you see that 2662-37G is an X20.

My X20 had 2662-37G sticked on it, but, below this sticker, I saw another sticker with 31G written on it.

When I'm looking in TuneUp Utilities, it shows 31G.

I had a look on the manual of the X20, it will only take 320 MB of RAM, with 64 MB soldered.

The X21 can be found with either 64 or 128 MB onboard.



W.

[icebag]

My "new" X20/X21 has developed an irritating fault. After several hours of problem-free use yesterday (installing OS and favourite programs) it switched itself off without warning.

Now it sometimes switches itself off after as little as 5 minutes, but sometimes runs for an hour or so.

It could be overheating I suppose. I will strip out the heat sink / fan unit and give it an overhaul.