Thinkpads Forum

[Moderator edit: moved from Official upgrade thread in order to keep both threads focused.]

Ok I read through a lot of this thread ..Not sure if I missed it but I'm trying to find out the MAX memory for a 770E . anyone??

I'm not 100% sure.

I think that according to IBM/Lenovo specs, the max is 288MB:
32MB onboard, plus two 128MB SODIMMs

According to one Forum member, the actual max capacity is 416MB:
32MB onboard, plus one 128MB stick, plus one 256MB stick.
(see Thinkpad 770E Questions (Memory and Video, and
compare to How to upgrade 770ed?)

Theoretically, you should be able to install two 256MB chips, but maybe the 770E/ED series has a problem with that memory configuration.

Also, I don't know how to figure out which 256MB chips would be compatible. If I had to guess, I would try low-density PC100 chips.

Phil.

Given that the 770E and the 600E both use the Intel 440BX chipset, I would say that there is a good chance that if you use low-density (16 chips) 256MB PC100 CL2 modules, as Phil suggests, you can get it up to 544MB.

The twbook.pdf does say that the max memory is 288MB for the 770E. It also says that the 600E has the same limitation but many people have populated that system with two 256MB modules. There has been some speculation that perhaps a BIOS upgrade is also needed for some systems to recognize that large of a memory module. I don't believe that it is necessary, but again, I don't own a 770E.

I have a 770ED and the IBM recomended max is 288 but if you can find a pc100 256MB and a pc66 128 then you can have 384. Thats what I have tried. The 256 belonged to a friend (he wanted it back for some reason).

One more thing. You may have to fiddle with different brands of whatever chips you are trying. The 770E/ED appears to have been amongst the most flakey and particular of the 770 series with respect to memory. At least one company (GoldenRAM) actually developed a memory chip configuration specifically for the 770E/ED that was different than the one used for other 770 machines. So just because one brand doesn't work, doesn't mean that other brands of the same basic configuration won't work.

Phil.

Thanks guys... When you say low-density what are you referring to? Registered and non registered ram? CAS latency??pc100 vs pc133???

Low density essentially means 16MB parts on the module. So, for a 256MB module you would need 16 individual memory chips (8 per side).

I don't believe any of the PC100 SODIMM modules are registered. CAS latency (CL) should be as fast as possible in order to have a better chance at being compatiible with your system. CL2 is pretty much the standard for PC100 modules. PC133 is available in CL2 but can be hard to find. CL3 was prominent for those modules.

@pkiff:

Do you have a part number for the GoldenRAM module?

(edit: Sorry, I noticed that I had put 16Mbit when I meant 16MB)

Thanks for the explanation.. If anyone can point me to some known working modules I'd greatly appreciate it.The ones on newegg seem to all be high density ram... I'm trying to upgrade my friends PC so he can get the most out of the short cash he has ...

rufunky wrote:I'm trying to upgrade my friends PC so he can get the most out of the short cash he has ...

If you are looking for cheap upgrades, then I wouldn't try to max out the memory on that 770E at 512: sticking in two 128MB 66MHz modules will give you 288MB, and that is plenty for an old PII 266MHz machine like that. Low density 66MHz 256MB chips are close to impossible to find and used, low-density 100MHz 256MB chips can run USD $40 or more, plus shipping. And you may not be able to install two 256MB modules, nor will you be able to be 100% sure if any individual 256MB module will work until you actually install it in your machine.

For 128MB modules, you should be able to buy just about ANY 144-pin SDRAM 128MB 66MHz SODIMM module, despite what I said above about the special GoldenRAM module. Just make sure that your seller has a return policy in case it turns out that it isn't recognized properly in your machine.

Here are some examples from eBay that claim compatibility with Thinkpad 770s, though I would note that two of them don't actually identify the 770E/ED specifically:
128MB Memory IBM Thinkpad 770E 9548-5xx 770ED 9549-5xx
New 128MB for IBM ThinkPad 390,570,600,600E,770!
128MB PC66 IBM ThinkPad 390 570 600 600E 770 Memory RAM

I don't recommend any of these sellers, nor have I got any experience with any of them, I'm just posting these to give you a head start on your own searches for these modules. I think that the actual value of a standard 128MB 66MHz module should be less than the USD $20 + shipping being asked for by the sellers above, but I guess it depends on where you live and whether you have any cheap local sources.

@rkawakami RE: GoldenRAM module part numbers:
I've got one installed in my machine I think, and I'll check if I can find part numbers for it. I've also got a 256MB module I can test in my 770E to see if I can boost the RAM up, though I probably can't afford to leave it in there, since it really belongs in my 770Z!

Phil.

Heh, I just upgraded my 770's RAM from 160 MB to 512 MB (BIOS sees all 512 MB, but it says only 416 is usable ) with a couple of Crucial PC133 256 MB RAM sticks from my dad's T23. I may just be lucky, but I never seem to have any problems with taking RAM from one computer and putting it into another.

Something interesting to note...Everest reports that there are 3 RAM slots (understandable, as one of them always says 32 MB, so that's the onboard). Slot 2 always reports 128 MB, even after I swapped the slots the RAM sticks were in. Slot 3 always reports 256 MB. So, added together, 256 + 128 + 32 = 416. The BIOS CAN SEE all 512 MB (actually 544 MB, since it includes the onboard 32 MB) , but it doesn't allow it to be used.

Since the BIOS is able to see all the RAM, I believe there is a way to hack the BIOS into allowing all 512 MB to be used by disabling the onboard 32 MB. That may be the only thing holding it back. Although I use Windows and I don't have a 770Z, I found this webpage (http://dqd.com/~mayoff/notes/thinkpad/770Z/memory.html) that says you can enable all the RAM from the Linux boot command line. If this is true, it would be possible to do a similar thing in Windows.

Hope this helps...

Sorry for the double post, but I don't like having huge posts like the one above.

I've been doing some more researching, and I found some information that supports my theory of disabling the onboard 32 MB of RAM to get 512 MB of RAM. The topic that I got the information from is How to upgrade 770ed?.

If you use 2 PC100 chips with the built in PC66 chip,then it will only recognize half of one of the chips....

Same thing happens to me.

You can use ONE PC100 stick with the built in PC66....!!!

So, if you mix the built-in PC66 with PC100 or PC133, one of the higher speed RAM sticks gets cut in half. I believe the reason 770X and 770Z users can go above 416 MB of RAM is that they can REPLACE or REMOVE the PC66 built-in stick of RAM. 770, 770E/ED users can't because it is soldered on. If the PC66 RAM can be disabled by a BIOS hack, the 770 and 770E/ED systems should be able to support just as much RAM as the 770X and 770Z systems.