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	Official Max	Unoffical Max	BIOS	Embedded Controller	Memory configuration successfully tested
ThinkPad A31p 2653-R8U	1 GB	2 GB	1.10	1.05	2 x Elpida 1 GB 200-pin DDR PC2700, FRU # 31P9835
ThinkPad A31p 2653-R??	1 GB		1.09	1.05	2 x Kingston 1GB 200-Pin DDR, Model# KTM - TP9828/1G
ThinkPad SL500	4 GB	8 GB	?.??	?.??	2 x 4GB 200-Pin DDR2 PC2-5300
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 T42 2373-CTO	2 GB		3.17	3.04	???
ThinkPad T43p 2668-WTB	2 GB		1.29	1.06	2 x Kingston 1GB 200-Pin 533MHz DDR2, Model KTM-TP3840/1G DDR2
ThinkPad T61p 6457-5GG	4 GB	8 GB	2.19	1.08	2 x Kingston 4GB 200-Pin 667MHz DDR2, Model # KTL-TP667/4GB.
ThinkPad T61p 6460-EEG	4 GB	8 GB	2.27 middleton (SATA-II modified)	1.08	2 x Samsung SODIMM 4GB PC2-5300 DDR2-667, Model # M470T5267AZ3-CE6 / 4GB.
ThinkPad T61p 6457-7XG	4 GB	8 GB	2.26	1.08	2 x Crucial 4GB 200-Pin 800MHz DDR2, Model # CT51264AC800. (PC2-6400)
ThinkPad T61p 6459-CTO	4 GB	8 GB	2.26	1.08	2 x G.Skill 4GB 200-Pin 800MHz DDR2, Model # F2-6400CL6D-8GBSQ (PC2-6400)
ThinkPad T61p 6460-8YG	4 GB	8 GB	2.26	1.08	2 x Crucial 4GB 200-Pin 667MHz DDR2, Model# CT2KIT51264AC667 ( 2x CT51264AC667)
ThinkPad T61p 8889-3FG	4 GB	8 GB	TBA	TBA	2 x Kingston 4GB 200-Pin 667MHz DDR2, KVR667D2S5/4G.
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 2525-CTO	1.5 GB	2 GB	2.09	1.02	1 x 2GB ( ??? ) BIOS claims 2.5 GB. Diagnostic POST and memtest86+ both test only 2 GB. Linux and Windows XP recognize 2 GB.
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.
ThinkPad X41 2525-F8G	1.5 GB	2 GB	2.06	1.01	1 x 2GB (Crucial CT25664AC667 DDR2 PC2-5300) BIOS claims 2.5 GB. Diagnostic POST and memtest86+ both test only 2 GB. Linux and Windows XP recognize 2 GB.
ThinkPad 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 Windows XP recognize 2GB.
ThinkPad X61 7675-K2U	4 GB	8 GB	?.??	?.??	Kingston 8GB (set of 2x4GB) 200-Pin DDR2, KVR667D2S5K2/8G Equivalent to 2 x Kingston KVR667D2S5/4G
ThinkPad X61 Tablet 7764-CTO	4 GB	8 GB	1.23	?.??	2 x Generic 4GB 200-Pin DDR2.
ThinkPad X61 Tablet 7762-94G	4 GB	8 GB	1.23	1.02	2 x Kingston 4GB 200-Pin DDR2, KVR667D2S5/4G.
ThinkPad X61 Tablet 7762-95G	4 GB	8 GB	1.23	1.02	2 x Kingston 4GB 200-Pin DDR2, KVR667D2S5/4G. Ubuntu 10.10 64bit shows installed memory size of 7,7 GiB.
ThinkPad X100e 3508-CTO	4GB	8GB	1.29	1.22	2 x G.Skill 4GB 200-Pin 800MHz DDR2, Model # F2-6400CL6D-8GBSQ (PC2-6400)
ThinkPad X200 7459-W2H	4 GB	8 GB	3.13	1.06	2 x KVR1066D3S7/4G.
ThinkPad X200s 7466-9QG	4 GB	8 GB	3.11	1.06	2 x KVR1333D3S9/4G.
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. The 600E (2645-8A0) with Bios INET36WW accept two modules of 256MB. The ram modules have 8 chips on each side. That results in 544MB. (RAM Typ: Micron MT16LSDF3264HG-133E4 PC133 CL3 sync). Processor is an Intel PII 366 PE, installed platform is Windows XP Pro with SP3.
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
ThinkPad T61p 6460-DVU	4GB	7LETC7WW (2.27) 04/08/2010	1.08	6GB:       4GB: Micron MT16HTS51264HY       2GB: Kingston KTH-ZD8000C6 Passed Windows Memory Diagnostic (Standard), but system became slightly unstable, app crash every 1-2 hours, failed Lenovo Toolbox memory test.

External Sources

• IBM's official Memory compatibility page