Unofficial maximum memory specs

Some ThinkPads are known to support more memory than their specs say. This page gathers information about those models, how much memory they can take and what special requirements that memory must fulfill.

Have a look at the Memory page for the official memory configs and partnumbers

Working memory configurations

The following table gives an overview of tested memory configurations that exceed the specified limits for that ThinkPad type.

ThinkPad	max. Specs	BIOS	Embedded Controller	Memory configuration successfully tested
ThinkPad T61p 6457-5GG	4 GB	2.19	1.08	2 x Kingston 4GB 200-Pin DDR2, Model# KTL-TP667/4GB
ThinkPad A31p 2653-R	1 GB	1.09	1.05	2 x Kingston 1GB 200-Pin DDR, Model# KTM - TP9828/1G
ThinkPad T30 2366-92U	1 GB	2.08	1.06	2 x Kingmax 1GB 200-Pin DDR SO-DIMM DDR333 PC2700, Model# MSAD42D-KI but see problem with T30 not booting with 1 GiB memory module. 2 x Generic Brand 1GB 200-pin DDR SO-DIMM PC2700 (p/n 89898E): BIOS recognizes 2048MB, but Gentoo sees only 1024MB
ThinkPad T43p 2668-WTB	2 GB	1.29	1.06	2 x 1GB Kingston KTM TP3840/1G DDR2 533MHz
ThinkPad X31 2672-C2G	1 GB	3.02	1.08	2 x 1GB Kingston KVR400X64SC3A/1G DDR400MHz. Newer documentation also states 2GB, but original one did not. Boots with 1 bar.
ThinkPad X31 2673-C2G	1 GB	3.02	1.08	2 x 1GB (Team Group Inc. TSDR1024M400 DDR400MHz) Boots with 1 x TSDR1024M400
ThinkPad X41 2528-5FU	1.5 GB	2.09	1.02	1 x 2GB (Transcend TS2GIB3847 DDR2 667 MHz) 1 x 2GB (FRU 73P3846 DDR2 PC2-4200) BIOS claims 2.5 GB. Diagnostic POST tests only 2 GB. Linux and XP recognize 2 GB.
X41 Tablet 1866-6HU	1.5 GB	2.03	1.02	1 x 2GB (Transcend JM667QSU-2G DDR2 667 MHz) BIOS claims 2.5GB. Diagnostic POST tests only 2GB. Linux and WindowsXP recognize 2GB.
ThinkPad 240 2609-40U	320MByte	IRETWWW76	n/a	Any PC100 256MB memory in 16-chip configuration
ThinkPad 240X	256MByte	unknown	n/a	Some PC100 256MB memory in 16-chip configuration may work. Chipset cannot handle more than 256MB
ThinkPad 570 2644-3AU	320MB	1.16 IMET65WW 11/11/99	n/a	Kingston KTM-TP390X/256 256MB MODULE FRU 16P6327 - 16 chips, 8 each side
ThinkPad 600  ?	288MB	?	?	416MB = 256MB low density PC100 SODIMM + 128MB PC66 SODIMM + 32MB PC66 on-board. It matters which SODIMM you put in which slot. This was first reported working on the Thinkpad Mailing List, and it worked error-free for me.
ThinkPad 770x 9549	448MB	1.11 IIET42WW 09/10/99	n/a	448MB = 256MB PC100 + 128MB PC66 + internal 64MB using IBM 256MB MODULE FRU 33L3070 PC100 CL2 - 16 chips, 8 each side 512MB = 2 x 256MB PC100 + 64MB internal booted up as well. 512MB is due to 440LX-Chipset limitations, 64MB are overlapping or unused.

Non-working memory configurations

ThinkPad	max. Specs	BIOS	Embedded Controller	Memory configuration unsuccessfully tested
ThinkPad A21m	512MB	?	?	2 x Microx 144-pin 512MB PC133 SDRAM SODIMM 32x16 8C 1 x Microx 144-pin 512MB PC133 SDRAM SODIMM 32x16 8C 1 x Microx 144-pin 512MB PC133 SDRAM SODIMM 32x16 8C + 1 x 144-pin 256MB PC133 SDRAM SODIMM

External Sources

• IBM's official Memory compatibility page