AddOn

ACP-EP Memory 256MB PC133 168-PIN SDRAM DIMM (MAC and PC)

Name: ACP-EP Memory 256MB PC133 168-PIN SDRAM DIMM (MAC and PC)
Brand: AddOn
SKU: B0000510CF

Bottom line: The AddOn ACP-EP Memory 256MB PC133 168-PIN SDRAM DIMM: 256MB on one 168-pin DIMM for PC133 SDRAM desktop slots; main trade-off: 256MB per stick is small; reaching 512MB+ takes multiple slots.

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By Mike Perry, Founder & Editor-in-Chief · Listing data updated 2026-10-06

Mike Perry — Hardware researcher since 2014. For retro PC hardware and period-correct parts, synthesises manufacturer documentation, community compatibility lists and marketplace listings rather than first-hand lab testing. Core beat: GPU performance across gaming, rendering, and local-LLM inference. About the author →

Pros & Cons

Pros

✓ 256MB on one 168-pin DIMM for PC133 SDRAM desktop slots
✓ Built to JEDEC standards, part number AO16C3264-PC133
✓ Listed as compatible with both Mac and PC desktops
✓ Unbuffered UDIMM format for standard non-server desktop boards
✓ Every module 100% tested and compatibility-guaranteed, per AddOn

Cons

✗ 256MB per stick is small; reaching 512MB+ takes multiple slots
✗ Desktop DIMM only; will not fit laptops that use SO-DIMMs
✗ Unbuffered, so not suited to servers needing registered memory
✗ Listing omits CAS latency, voltage and chip-count details

Manufacturer description

AO16C3264-PC133 is an INDUSTRY STANDARD 256MB SDRAM 133MHz/PC133 DIMM memory module for Desktops. This memory module is built to JEDEC Standards. All Add-on memory products are 100% tested and 100% guaranteed to be compatible with the systems it is intended for.

SpecPicks Verdict

SpecPicks scored AddOn ACP-EP Memory 256MB PC133 168-PIN SDRAM DIMM using a rating × review-volume × price-fit model applied to published specs and reviews across the memory & ram category. AddOn's memory & ram lineup sits within the broader category mid-tier; price and specs are the deciding factors over brand loyalty here. Judge it on the specification table and the price rather than on sentiment: check the figures that decide your use case, then put it side-by-side with two or three close alternatives in the Compare tool before clicking through.

Common buyer scenarios for memory & ram of this kind: matching it to an existing build, replacing a failing part, or upgrading from a previous-generation equivalent. Check the spec table below against your current setup — particularly socket / form-factor / power-rating fields — and confirm compatibility on the retailer's listing before purchase. Prices and stock are set by the retailer and may have moved since this page was last updated.

Key Features

256MB PC-133MHZ UDIMM
DR COMPUTER MEMORY

Full Specifications

Brand	AddOn
Voltage	3.3 Volts
RAM Size	0.25 GB
Model Name	MEMORY UPGRADES
Unit Count	1.0 Count
Form Factor	Desktop
Memory Speed	133 MHz
Model Number	AO16C3264-PC133
Compatibility	PC, Mac
Number of Pins	168
Mfr Part Number	AO16C3264-PC133
Compatible Devices	Desktop
Data Transfer Rate	133 MHz
Memory Form Factor	DIMM
Additional Features	Lightweight
Computer Memory Size	0.25 GB
Warranty Description	Limited lifetime warranty
RAM Memory Technology	SDRAM PC133
Global Trade Identification Number	00662919006391

Ready to buy?

ACP-EP Memory 256MB PC133 168-PIN SDRAM DIMM (MAC and PC) is vintage hardware; the used and vintage market on eBay carries most of the live inventory. Prices and condition vary by seller and move in real time, so we link the live listing rather than quote a cached price. It also has an Amazon listing — check it for current price and availability. SpecPicks earns a small commission on qualifying purchases — thank you for supporting independent review work.

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