A21p allow pc133 so-dimm?

Message

liquid · #1 Post by **liquid** » Sat Jul 24, 2004 7:21 pm

I have an a21p and was wondering if there is any way to get a pc133 so-dimm to work in it instead of a pc100 so-dimm. hardware spec wise, it shouldn't matter, since the pc133 so-dimm has the same interface, just runs at a higher clock.

putting one in though, results in a system that doesn't turn on. any pointers or are they just incompatible and i am SOL?

thanks

http://www-307.ibm.com/pc/support/site. ... MIGR-55644 is the best reference i have found

JHEM · #2 Post by **JHEM** » Sun Jul 25, 2004 8:13 am

Sorry,you're SOL. I've tried innumerable PC133 sticks in Thinkpads built on the Intel 440BX chipset, like the A21p, and have yet to find one that will work.

You're stuck with using relatively rare (and expensive!) lo-denisty PC100 sticks.

Regards,

James

liquid · #3 Post by **liquid** » Sun Jul 25, 2004 4:22 pm

sad to hear. if i worked for ibm, i would update the bios to alleviate that. just seems silly.

JHEM · #4 Post by **JHEM** » Mon Jul 26, 2004 7:49 am

liquid wrote:sad to hear. if i worked for ibm, i would update the bios to alleviate that. just seems silly.

It's not something that IBM can correct in the BIOS, it's an inherent flaw in the Intel 440BX chipset.

Regards,

James

AssPenny · #5 Post by **AssPenny** » Thu Aug 12, 2004 3:50 pm

PC133 will work in your A20, but not all pc133 is created equal. Some are constructed of High Density chips and some are the Low Density chips. LowD chip memory will work just fine. The HighD chips wont run (or run very well) on a 440bx chipset. You just need to learn the difference between the two before you go shopping for it. PC133 wont make it run any faster tho.

targa · #6 Post by **targa** » Wed Apr 05, 2006 3:51 pm

Sorry to renew this thread, but how can I determine High Density chips ?

I have 3 different 144pins that won't work in my A21m-2628

Infineon HYS64V32220GDL-7-5-CL2
chips: HYB39S256160CTL-7.5

Hynix HYM72V32M636BT6-H AA
HY57V5616208T-H

Elpida EBS26UC6APS-75
D52516APTA-75

They all have the IBM label FRU: 19K4655 but they all behave differently in the A21m.

//Tomas

Website · #7 Post by **tfflivemb2** » Wed Apr 05, 2006 4:06 pm

Low Density sticks have twice the number of chips on them as High Density. For example, a High Density 256mb stick would have 8 chips, 4 on each side....whereas a Low Density stick would have 16 chips, 8 on each side.

JHEM · #8 Post by **JHEM** » Wed Apr 05, 2006 5:29 pm

They're 256MB PC133 sticks: http://www-307.ibm.com/pc/support/site. ... IGR-4NVU4N

Here's what they'll work in: http://www-307.ibm.com/pc/support/site. ... MIGR-55644

Your A21m requires IBM 33L3070 PC100 low density memory. Search eBay for the part number, you'll find tons of it.

Regards,

James

targa · #9 Post by **targa** » Fri Apr 07, 2006 2:46 pm

Thank You...
/Tomas

targa · #10 Post by **targa** » Wed May 03, 2006 1:29 am

Price is tough for these low density chips. About twice the price as the regular ones.
Anyway, is there a possibility to have more than 512MB ? Probably not even with soldering skills, because of the lacking space?!

/To

JHEM · #11 Post by **JHEM** » Wed May 03, 2006 7:05 am

No, you can't install more than 512MB of RAM.

Regards,

James

targa · #12 Post by **targa** » Fri May 05, 2006 8:42 am

Would a Memory Card named: "PC2-4200 CL4 200-PIN SODIMM" fit?

It's probably too slow, eller ? Which bus speed the A21m uses ?
/Tomas

EDIT: SORRY: 200pin wouldn't fit anyway...

Website · #13 Post by **tfflivemb2** » Fri May 05, 2006 9:07 am

As stated above, they need to be PC100, not PC4200...LOW DENSITY (16 chips, 8 on each side)

Also, the correct pin count is 144pin.