Wahhh, my new RAM will not work, a question please

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Purcy · #1 Post by **Purcy** » Sun Dec 17, 2006 1:52 am

Today I got my HDD upgraded to a 80GB, I had wanted a 60GB but our friend who owned the computer tech store threw an 80GB (5400rpm) in there and surprised me. He cloned the new drive for free too and it is working great. I also asked him to double the RAM to 512MB, but he tried many different brands of 2 sticks of 256 in the slots and none of them would be recognized in BIOS as 512, it still said there was only 256MB RAM. He did say that all the sticks he had in stock were all double sided (not too sure what that means) and he was wondering if that mattered in my IBM. Perhaps I need all single sided sticks, since the two 128MB sticks he took out where single sided. Could someone suggest an answer for me, do I need only single sided sticks for my T22. Thank you in advance, I'd really like to get this RAM doubled for more speed.

#2 Post by **rkawakami** » Sun Dec 17, 2006 2:28 am

The T22 takes (normally) PC100 modules, although some PC133s can be used. The T21 I have uses identical modules to the T22 and the ones that I currently have in my system are "low density" 128MB modules. They have 8 chips (4 on each side) and are marked as PC100 CL2 (FRU 20L0265).

I pulled out two 256MB PC100 modules out of one of my 600X systems and plugged them into the T21 without any problems. Windows reports a full 512MB. These 256MB modules are also "low density" and have a total of 16 devices (8 per side).

Do you have any part numbers/markings from the modules that you've tried or are using now?

Purcy · #3 Post by **Purcy** » Sun Dec 17, 2006 9:59 am

Thanks for replying Ray. I will see if I get that info, I suppose I could power this down and open up the slot cover to see. I seem to be only reading 128MB of RAM since he had that cover off, I am thinking something is off in that area, like only one slot is working.

Purcy · #4 Post by **Purcy** » Sun Dec 17, 2006 12:40 pm

Well while I was in the memory slot area doodling around, I unclipped both sticks and put them back in and reseated the cover and tightened down that screw real good ........... and now I am reading 256MB RAM again! I think perhaps the cover was not seating right when Ron tried out the 512MB since when I unscrewed the cover, the right corner of it popped up real fast, sort of crooked. Anyway, at least I have my full memory back until we try out the 512 again.

Website · #5 Post by **tfflivemb2** » Sun Dec 17, 2006 2:44 pm

My T21 is running 2 256MB sticks of PC133 ram. Whether they are PC100 or PC133, they HAVE to be low density, as Ray pointed out.

pianowizard · #6 Post by **pianowizard** » Sun Dec 17, 2006 2:49 pm

The OP tried 256MB sticks that were double-sided. Aren't all double-sided PC100/133 sticks low density, with 8 chips on each side? I have never seen high-density 256MB sticks, so I don't know for sure.

#7 Post by **rkawakami** » Sun Dec 17, 2006 2:51 pm

The 256MB low density modules should have 8 per side. "Low density" generally refers to 16MB DRAM components. 16MB x 16 = 256MB. Just because they are "double-sided' does not make them "low" or "high" density; you have to take into account how MANY components are on the board. And yes, I believe I've seen some high density 256MB modules. They will have 4 per side. I think Macs take these type of memory modules.

pianowizard · #8 Post by **pianowizard** » Sun Dec 17, 2006 2:58 pm

rkawakami wrote:The 256MB low density modules should have 8 per side. "Low density" generally refers to 16MB DRAM components. 16MB x 16 = 256MB. Just because they are "double-sided' does not make them "low" or "high" density

Thanks for the info. BTW, in my last post, I actually meant "8 chips on each side", not "4".

#9 Post by **rkawakami** » Sun Dec 17, 2006 3:05 pm

Just realized that reading some of this can get confusing... Let me try to be succinct about this:

To determine if you have a low or high density module means you must figure out what the capacity of each individual memory chip is. Low density is 16MB (megabytes) or smaller. High density is 32MB or larger.

If you are told your have, or read the markings on the module, that it is supposed to be 128MB or 256MB, then take that number (128 or 256) and divide it by the total number of "chips" on the module (count both sides!). If the result is 16, then it's low density. If the result is 32, then it's high density.

Purcy · #10 Post by **Purcy** » Sun Dec 17, 2006 4:22 pm

Thank you all for this info. I have two 128 sticks in there now, they have 4 modules on each side, so they are (16) low density. After Christmas our friend is going to re-try seating the two 256 sticks for me, I want that full speed ahead kind of feeling

I am happy with the little speed increase just from the bigger HDD. This was also his virgin run in opening up a Thinkpad, holy cow are we that rare of a breed?

Have a good evening all.

Wahhh, my new RAM will not work, a question please

Wahhh, my new RAM will not work, a question please

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