Model number and memory upgrade

[NFS73]

Hi all! I'm new to this forum and I'm writing here because I need some help (or better a confirmation to my thoughts! ).
I'm a happy owner of a second-hand, good old ThinkPad 600E; the machine works great for it's lightweight uses i need it for (WWW navigation, word processing and so) but I think that a little memory upgrade from the current 196Mb would help with Win2k i run on it (don't suggest me to DOWNgrade to Win9x cause i WILL NEVER! ).
So I'm planning to substitute the 32Mb DIMM (now is: 32 base + 32 DIMM + 128 DIMM = 196) with a 128Mb one just hitting the 288Mb machine limit. Problem is: in my city's shops i was only able to find PC133 SODIMMS that don't work on my ThinkPad (try before buy! ); now i've found an online shop but provided i can't try before what i buy online I need make clear about model number of my machine.

First of all, I'm from EU (and my ThinkPad too! ) and I think the problem is basically between European and American IBM model numbering that differ. My Thinkpad is a 600E and is a Pentium II 366Mhz with 66Mhz FSB.
On back-label of my notebook is written:

TYPE 2646 - 8AG

but "googling" around i saw that (american) model 2646 is the PIII-500Mhz 600X (that uses PC100 RAM) and my SHOULD be a 2645 (if born in the USA ).

I think I can safely buy the 66Mhz DIMM even if it's referred to be used with model 2645. Am i right?

Thanks in advance for your help
Emilio

[JHEM]

Emilio,

Your model is equivalent to a US model 2645-8AU.

If you read this: http://www-306.ibm.com/pc/support/site. ... IGR-4E4RG3 you'll see that your Thinkpad can actually take two PC100 256MB SO-DIMMs for a total installed memory of 544MB. The memory must be PC100 and lo-density, e.g. having eight memory chips per side on the SO-DIMM, not four.

But to answer your question, yes you can use the PC66 128MB memory.

Regards,

James

[sktn77a]

Emilio:

I think Win2k is probably the optimum OS for the 600E (I have WinXP on my 600E 366 but I could be persuaded to "downgrade" to W2k). You can use 256Mb modules if you update the BIOS to v36 (not v26 as the IBM website says in some places). The 600E is VERY picky about memory - follow James' advice and don't get cheap RAM. You can use 128 or 256Mb PC66 or PC100 with the BIOS upgrade if it's the right type, otherwise, without the BIOS upgrade get 128Mb PC66.

[BillMorrow]

that 600E will support two 256meg parts as long as the bios is up to date..

[NFS73]

Thanks folks for all the replies. But now i'm bit MORE confused!
How come my 66Mhz machine should use PC100 and not 66 memory?
Unfortunately I've been able to try on it only PC133 DIMMs (a 256Mb and a 128Mb module), both didn't work and so no big news from that.
By the way, the PC100 DIMM costs twice as much as the 66 (old parts market! ) but most of all i wanna be sure what I buy online (with no chance to try) will work.
About the 288Mb limit: Crucial site (the ones from I think I'll buy the memory) says that the 600E (PC100) has that limit. But I don't care too much cause 256Mb are way too expensive!
For sktn77a: I used to have WinXP on this same machine before, but with just 196Mb it was all the time working with a big swap file on the HD. Now with Win2k, the swap file is much less used but I miss a bit the nice XP interface and to have Win2k properly handle power management I had to update BIOS to v36.

[NFS73]

Just a little new tip: I took out one of the two modules (the 32Mb one) it has just 4 chips on one side and on other there's a label with written:

32MB (4Mx64) 3.3V 66MHz SDRAM NP
^^^^

[NFS73]

(Sorry for the double post, i just hit "submit" instead of "preview" )

So it's a 66 Mhz memory module!

[hausman]

Find the IBM FRU number for the memory for your 600E on the IBM website. Then go to eBay and search for that FRU. You should be able to find used memory at reasonable prices from vendors who guarantee that it will work on your machine.