I'm sorry if this had been answered somewhere.
My T23 has 512MB and I would like to upgrade to 1GB with 2 sticks like this.

Does anyone know if I can have 1TB with these sticks ?

I'm a little bit scared because of the warning at the end:

512MB (1 stick of 512MB)
Type: SDRAM SODIMM
Speed: PC133 133Mhz
Base: 144 Pins for Laptop PC
ECC, Reg: No, No
Timming: CL 3
Density: Low Density 32X16 8Chips
Condition: Brand New
Warranty: Lifetime warranty

"Note: Not compatible with Apple Mac machine. Intel 830 and Ali/Trident chipsets laptops are not compatible with this 32x16 type memory"

http://www.ebay.com/itm/512MB-PC133-SDR ... 27bb6020dd

I saw a bunch of these on ebay too. From what people on this site describe, these are not low density chips. Years ago I had a bad ebay transaction looking for desktop pc100 low density 512 modules. All the seller did was sticker a 256 chip as 512.

It looks as though they sold alot of them, is there any feedback from the buyers? I didn't want to risk 35$ personally.

Yes, sometimes they just copy-paste the specs.
I have no idea if the T23 take ECC ? No ECC ? Low-density ? High-Density ?
Most of the time they show picture of one side. And we have no idea if the other side is empty.

If you had bought similar stick (based on the photo they show), then please help me. Thank you so much.

Thanks.

Why don't you just post a WTB (want to buy) ad in the forum's marketplace and get a known good 1GB set or whatever you need for that T23 instead of relying on feebay?

And no, I don't have anything to offer you along those lines...

Happy hunting.

@T23_thinkpad:

Welcome to thinkpads.com!

Concerning a T23, memory "density" (i.e., low vs. high) is not really an issue. For all intents and purposes, when people talk about low density modules, those are anything that uses 16MB components, while high density use 32MB chips or bigger. The real difference between the two "densities" has to do with a specific timing specification known as the refresh rate. The chipset used in the T23 generates the refresh rate which requires the use of high density (32MB or larger) components. When talking about 512MB modules, you need 16 32MB parts or 8 64MB parts, to get a total of 512MB.

Unfortunately, many eBay sellers continue to say their 512MB modules are low density if they only have 8 components on it, while those modules that have 16 components are high density. They are misconstruing the issue, thinking that the number of components is the density (8 being lower than 16), while the truth really has to do with how many bytes of storage is in each component (16MB is lower than 32MB).

You explained it so clearly. I got it now.
So total of the stick is 512MB.
There are 8 chips (4 chips on each side of the stick).

Therefore: each chip = 64MB.

As for the "32X16" on the listing : I don't know if that means something, or a by-product of "copy-paste" or what.

The 32X16 is referring to the size of the individual memory component; 32M addresses by 16 outputs. Since 8 outputs is 1 byte, the total storage capacity is 32M by 2 bytes or 64MB. Oh, and as far as the ECC vs. non-ECC goes, the T23 does not need (nor can it use) any extra error correction bits. Maximum memory capacity for the T23 is 1GB. It's what I have in all of my own T23s.