PC2-5300
| NOTE! As PC2-5300 is getting increasingly difficult to acquire, PC2-6400 can be used instead. Using PC2-6400 may or may not increase the performance of your model, as some models may underclock it to their respective original DRAM speeds. PC2-5300This is DDR2 SDRAM at 667 MT/s in a 200-pin SO-DIMM form-factor. DDR2-667 may also be interchangeably referred to as PC2-5300. | 
Available DRAM modules from Lenovo
| DDR2 type | Individual / Single-Pack Option Marketing Part Number | 25-Pack Option Marketing Part Number | Field Replacement Unit (FRU) Service Part Number | 
| Non-ECC, unbuffered 2Rx16 256MB PC2-5300 CL5 | 40Y7732 | N/A | 40Y8401 | 
| Non-ECC, unbuffered 2Rx16 512MB PC2-5300 CL5 | 40Y7733 | N/A | 40Y8402 | 
| Non-ECC, unbuffered 2Rx16 1GB PC2-5300 CL5 | 40Y7734 | 51J0502 | 40Y8403 | 
| Non-ECC, unbuffered 2Rx8 2GB PC2-5300 CL5 | 40Y7735 | 51J0548 | 40Y8404 | 
Taken from Lenovo, Memory compatibility - Notebooks.
Models that support this technology
| Models | Soldered on motherboard | SO-DIMM Slot 1 | SO-DIMM Slot 2 | Official Max-Memory | Unofficial Max-Memory | 
|---|---|---|---|---|---|
| T61, T61p | N/A | Occupied | Depends | 4GB | 8GB3 | 
| T60, T60p | N/A | Occupied | Depends | 3GB1 2 | 3GB1 2 | 
| X300 | N/A | Occupied | Depends | 4GB | 8GB3 | 
| X61, X61s, X61 Tablet | N/A | Occupied | Depends | 4GB | 8GB3 | 
| X60, X60s, X60 Tablet | N/A | Occupied | Depends | 3GB1 2 | 3GB1 2 | 
| SL300, SL400, SL500 | N/A | Occupied | Depends | 4GB | 8GB3 | 
| SL400c, SL500c | N/A | Occupied | Depends | 4GB | 8GB3 | 
| R61, R61i, R61e | N/A | Occupied | Depends | 4GB | 8GB3 | 
| R60, R60i, R60e | N/A | Occupied | Depends | 3GB1 2 | 3GB1 2 | 
| G50 | N/A | Occupied | Depends | 3GB1 2 | 3GB1 2 | 
| Z61t, Z61e, Z61m, Z61p | N/A | Occupied | Depends | 3GB1 2 | 3GB1 2 | 
| FOOTNOTES [Δ] | 
- Attained via two 2Rx8 2GB DDR2 non-ECC SO-UDIMMs, may or may not be possible with 1Rx8 2GB DDR2 non-ECC SO-UDIMMs.
- The actual amount of usable memory will be lower than 4GB, due to the 32-bit limitation of the i945 series chipsets. Depending on the amount of I/O space required by certain devices, the amount of usable DRAM may be as low as 3.75GB to 3GB.
- Attained via two 2Rx8 4GB DDR2 non-ECC SO-UDIMMs, not possible with 1Rx8 4GB DDR2 non-ECC SO-UDIMMs. (if they do exist)
Available DRAM modules from other companies
| Manufacturer | Partnumber | Description | Tested on model | 
|---|---|---|---|
| Crucial | CT2KIT12864AC667 | 2x1 GB | R60e (0657-3LG1) | 
| Crucial | CT25664AC667 | 2 GB | T60 (1951-A47) | 
| Crucial | CT2KIT6464AC667 | 2x512 MB | |
| Crucial | CT12864AC667 | 1 GB | |
| Crucial | CT6464AC667 | 512 MB | |
| Crucial Rendition | RM12864AC6674 | 1 GB | T60 (2007-49G) | 
| Transcend | TS2GIB3847 | 2 GB | R60 X41 | 
| G.Skill | F2-5400PHU1-1GBSA | 1 GB | T60p (2007-93G2) | 
| Corsair | VS1GSDS667D2 | 1 GB | Z61m | 
| Corsair | VS2GSDS667D2 | 2 GB | T60 (2007-FSG) Z61m X60 (1707-V28) | 
| Corsair | VS4GSDSKIT667D2 | 2x2 GB5 | R60 (9456-HTG) | 
| G.Skill | F2-5300CL5S-2GBSA3 | 2 GB | 
| FOOTNOTES [Δ] | 
- The memory module that was shipped with this laptop had the same Micron logo as the modules from Crucial, which is a division of that company.
- Memory for T60p spec is CL5, but this module which was CL4 works fine. The product page at G.Skill describes it wrongly as a CL5 module.
- Some users reported the RAM module is in fact overclocked from 533MHz to 677MHz, hence some systems may report 533MHz and/or CL4.
- Crucial's website doesn't list Rendition memory, but the memory is clearly labelled as Crucial Rendition by several resellers.
- The actual amount of usable memory will be lower than 4GB, due to the 32-bit limitation of the i945 series chipsets. Depending on the amount of I/O space required by certain devices, the amount of usable DRAM may be as low as 3.75GB to 3GB.

