PC-133

PC133 This is SDRAM at 133 MHz in a 144-pin SO-DIMM form-factor.

Available DRAM modules from IBM

SDR type	Option Part Number (OPT)	Field Replacement Unit (FRU)
Non-ECC, unbuffered 1Rx8 64MB PC133 CL3	19K4650	19K4651
Non-ECC, unbuffered 1Rx8 128MB PC133 CL3	19K4652	19K4653
Non-ECC, unbuffered 1Rx8 256MB PC133 CL3	19K4654	19K4655
Non-ECC, unbuffered 2Rx8 512MB PC133 CL3	19K4656	19K4657

Models that support this technology

Models	Soldered on motherboard	SO-DIMM Slot 1	SO-DIMM Slot 2	Official Max-Memory	Unofficial Max-Memory
A30, A30p	N/A	Occupied	Depends	1GB1	1GB1
T23	N/A	Occupied	Depends	1GB1	1GB1
X30	N/A	Occupied	Depends	1GB1	1GB1
X22, X23, X24	128MB	Depends	N/A	640MB2	640MB2
R303, R31	N/A	Occupied	Depends	1GB1	1GB1

FOOTNOTES [Δ]

1. Attained via two 2Rx8 512MB PC133 non-ECC SO-UDIMMs, not possible with 1Rx8 512MB PC133 non-ECC SO-UDIMMs. Irrelevant uninteresting fun fact: 1GB PC133 SO-DIMMs exist, but they're generally ECC and registered/buffered. Sometimes, they come in 4Rx8 or 2Rx8 configurations, which may not be supported by the memory controllers used in normal laptops.
2. Attained via one 2Rx8 512MB PC133 non-ECC SO-UDIMMs, not possible with 1Rx8 512MB PC133 non-ECC SO-UDIMMs.
3. Comes with factory-installed PC133 SDRAM for some reason, but the memory controller is limited to PC100 speeds.

Available DRAM modules from other companies

Manufacturer	Partnumber	Description	Tested on model
TBD	TBD	TBD	TBD