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If your motherboard supports the larger modules and total capacity, 512 MB is the cautious upgrade from 256 MB. Choose 1 GB only after confirming both the board’s memory limits and that your operating system can use that amount reliably. “PC-133” and “CAS 2” alone do not establish compatibility.
What to check before choosing a capacity
The right upgrade depends on two missing details: your exact motherboard model and your operating system. Find the board model in its manual, on the board itself, or in the computer manufacturer’s documentation. Then consult the board manual or official memory compatibility list before buying.
Check more than the advertised PC-133 speed. The documentation should establish the maximum total memory, supported capacity per DIMM, module organization or memory density, voltage, and whether the board requires unbuffered or buffered and ECC or non-ECC memory. A DIMM can be the right general type and still be incompatible with a particular board.
CAS 2 is a timing rating, not proof that a replacement module will work. The available board information does not establish whether an unidentified motherboard requires CAS 2 or how it handles modules with different timings. Follow the timing and mixing guidance in your board’s documentation.
#1 Best Overall
- 512 MB SDRAM memory upgrade
- 168 pin DIMM; PC133 speed
- This desktop memory is both MAC and PC compatible
- This allows SDRAM to burst the second and subsequent, contiguous characters at a rate of 10ns
- Lifetime warranty
512 MB or 1 GB: how to decide
| Target | When it makes sense | What must be confirmed |
|---|---|---|
| 512 MB total | A conservative target if the board supports it, particularly while the motherboard or OS details are still being checked. | The board must support the specific DIMM capacity and configuration needed to reach 512 MB. |
| 1 GB total | A reasonable option when you want the larger capacity and have verified support for it. | The motherboard must support 1 GB in the intended module layout, and the OS must be able to use that amount reliably. |
Motherboard limits vary. For example, the ASUS A7VL133-VM manual specifies PC100/PC133 support, DIMMs from 8 MB through 512 MB, and up to 1 GB total; those figures apply to that model, not to every PC-133 board (ASUS A7VL133-VM User’s Manual). Kingston’s page for the ABIT KT7E lists configurations up to 1.5 GB, another board-specific example rather than a general PC-133 limit (Kingston memory for ABIT KT7E).
Check the operating system, especially on Windows 98 or ME
Windows memory limits differ by release and edition, so a recommendation for an unspecified OS would be unreliable. Microsoft’s documentation lists limits by Windows and Windows Server version and edition; use the entry for the exact OS installed on this computer (Microsoft: Memory limits for Windows and Windows Server releases).
Rank #2
- 1GB (256MB x 2) SDRAM PC133 LAPTOP Memory Module (144-pin SODIMM, 133MHz)
- Genuine MemoryMasters Brand
- Lifetime Warranty!
- 144-pin SODIMM 133MHz
There is also a legacy-OS caveat: an ASRock memory FAQ search result reports an “insufficient memory” initialization error with 1 GB or more in some Windows 98/ME configurations. That is a reason to check whether the warning applies to your particular board and OS, not evidence that every Windows 98/ME computer has the same limit (ASRock Memory FAQ).
Do these 3 things before closing this tab:
1Clear out junk files and repair common Windows errors2Fix the driver behind crashes, sound loss and screen glitches3Repair Windows errors before they cause bigger problemsOrder the right PC-133 module
- Identify the motherboard. Record the exact model and revision, if available; do not infer compatibility from the installed 256 MB DIMM alone.
- Read its memory specifications. Confirm the total limit, supported DIMM sizes, module organization or density, voltage, and ECC/buffering requirements.
- Check the OS. Verify that the installed Windows version and edition—or other operating system—can use the target capacity, and investigate any legacy startup caveats.
- Match the listing to the specification. Search for “PC133 SDRAM DIMM 168-pin,” then narrow results to the capacity and organization your board supports. Buffalo’s product information confirms this physical product category; it does not establish whether a particular listing is available now or will work in your computer (Buffalo PC/133 168-pin DIMM information).
Do not order solely because a listing says PC-133, 168-pin, or CAS 2. The exact motherboard’s documentation must match the module’s specifications.
Quick Recap
Best Value
- 512MB printer memory upgrade
- Part#: Brother -512MB-PC133S
- 100% Compatible with Lifetime Warranty
- Manufactured by Keystron, LLC
- Keystron is a registered trademark of Keystron, LLC
Rank #4
- Speed: 133MHz PC133
- Capacity: 512MB
- Warranty: Lifetime
- Form Factor: 144 pin SODIMM
- Type: Non-ECC
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