T23 512MB modules: 8-chip Samsung vs. 16-chip Micron *PICS*

[rkawakami]

More additions to the 512MB PC133 CL3 inventory:

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0091082049

Five modules of Samsung M464S6453CKS-L7A for $197.35, shipped. Currently undergoing checkout in three 1.2Ghz T23s. After almost 4 hours the two systems with 1GB of memory have gone through two and a two-thrids passes of the standard diagnostics without errors. The third T23 with only a single 512MB module is already done with five passes.

The eBay seller wasn't exactly close when he said similar to what was pictured (a Micron MT16LSDF6464). The Micron modules use 16 32Mbit x 8 devices to get the 512MB. The Samsung modules have 8 64Mbit x 8 devices. Yet either solution will work in the T23 as the laptop appears to use/require the refresh specification of 8K cycles every 64ms that is common to both modules.

Which one is better to use? While both modules functionally work in the system, the Samsung module appears to have a slight edge in the active power consumption department, while the Micron is better when the modules are in power down mode (laptop in standby). At least that's what the datasheets say. Given that the published limits are maximum values and not typical, it's hard to declare without actually measuring the current with a tester. I don't know how accurate MobileMeter would be in measuring the power drain difference between the two modules, assuming one could run identical systems side-by-side, or be able to repeat the power measurements with one set of modules, then the other.

ref:
Micron MT16LSDF6464 datasheet
Samsung M464S6453CKS datasheet

[Paul Pennington]

Ray;

Good information. You should put the T-23 memory information and pictures you've collected on your web site. There appear to be lots of varieties even on the IBM-labeled 512 MB memory. I love collections.

--Paul

[rkawakami]

Hmm... a gallery of various memory modules that have been tested to work in a T23, huh? I'll put that on my list of things-to-do. It may be a fairly short list for the 512MB modules as I like the Micron one I referenced above. But I do remember buying some "off-brands" before so there may be a couple of interesting ones.

At this point I think that almost ANY PC133 512MB module that operates at CAS latency 3 (CL3), or CL2, can be used in a T23, IBM FRU, or not. There are some differences in module design that can affect their performance in various systems. That's why computer manufacturers generally go through a qualification process for any new module, or if a significant change has been made to an existing one (new chip design or a change in the layout of the traces on the memory module). That is how they guarantee that a particular brand/type of module will work in their systems. I usually prefer to stick to the major players in the memory business (Micron/Crucial, Samsung, Mitsubishi, Mosel Vitelic/ProMOS [I'm an employee]) but I will buy others if the price is good (currently <$42) and the seller accepts returns.

[Paul Pennington]

[quote="rkawakami"] Mosel Vitelic/ProMOS [I'm an employee]

I didn't know that. I just bought a couple of your company's products on eBay -- 512MB IBM branded. I've received one so far, worked fine in my T23. Don't recall seeing this brand before. Odd, they were from two different sellers, but were made two months apart.

[rkawakami]

Mosel Vitelic is a merger between two start-ups, Mosel and Vitelic (what else ) back in '92 or so. We (MV) used to be in the DRAM business until prices took a huge fall and competition got tougher (4 or 5 years ago). ProMOS was actually a joint venture between MV and Siemens (Infineon). They pulled out and in the end, ProMOS swallowed up MV. Sort of the son buying out the parent. ProMOS continues to make DRAM, while MV is now concentrating on designing flash and embedded memories. Module makers will buy ProMOS or MV branded memory and assemble it onto their on boards.

Logos:

Mosel Vitelic


ProMOS

[rkawakami]

Okay, had a few minutes to whip up a new web site...

http://www.rkawakami.net/ibm_t2x/512mb_modules/

The 9 or so T23s at my feet (literally since I keep them under a desk) were opened up, memory eyeballed, and lobotomized if they contained a 512MB module. Said module was then scanned and image uploaded to my site. I was only able to find three different 512MB modules in the inactive systems. I have two more in the T23 I'm using at the moment so I'll get to those later. The two systems with my daughter in L.A. have four more modules so I don't have access to them to know what they are.

[Paul Pennington]

Awesome, Ray. I can see I'd better be careful what I say around you -- it may be completed and posted on the web by the next morning.

I think I remember seeing a utility program somewhere that would read some data programmed into a memory module and identify the manufacturer. Might save you some time opening them up if it was a module you already had. Or maybe I am wrong -- it happens.

[rkawakami]

I use CPU-Z (v1.36) to get data from a running system. It does have two tabs on the program where you are supposed to get information about the memory (installed size and bus timing settings) and SPD (Serial Presence Detect). The SPD info is stored on a separate memory chip on each module. It contains exactly what you describe; manufacturer, part number, serial number, build date. However, CPU-Z does not seem to support the T23's chipset as I never see these two tabs filled with data. It does work on the A31 I use at work, but not any of the T2x systems.

In any event, I would have had to power up the systems, wait for Windows to load, launch the program (if it was already installed), and read the tabs. Much faster to use a screwdriver . It would be a perfect solution for finding out what my daughter's two systems have, but she's pretty handy with opening up the system. She know how to swap the hard drive, install an Ultrabay HD adapter and use Ghost to backup her entire system. I'd trust her to open up the memory bay and look around.

[Purcy]

but she's pretty handy with opening up the system. She know how to swap the hard drive, install an Ultrabay HD adapter and use Ghost to backup her entire system. I'd trust her to open up the memory bay and look around.

Awesome!! My kind of woman.

[rkawakami]

Awesome!! My kind of woman.

I never thought she would become a computer nerd but she's trying to put together a web site for the small design firm she works for. Self-taught by reading a couple of HTML books and poking around on-line (just like her "old man" ).

I will have to correct something I posted earlier...

The most current version of CPU-Z that I downloaded (v1.39) does present the memory timing on my A31 but still does not fill in any data from the SPD. And it still does not work on my T23 (memory timing or SPD info tabs).

[Purcy]

I have CPU-Z vers 1.38 and it also shows memory timing but no data on the SPD tab; since I only own """"1"""" Thinkpad, I'll assume you know it is for the T22