I486 OverDrive
Intel's upgrade processors for 486-based personal computers.
The i486 OverDrive is a category of Intel i486 microprocessors specifically produced for upgrading personal computers. These processors were based on Intel486 DX2 technology and featured qualities distinct from standard i486s of the same speed steppings, such as built-in voltage regulators, different pin-outs, write-back cache instead of write-through cache, built-in heatsinks, and fanless operation.
- 20 mhz fsb, 40 mhz clock speed odp price
- US$549, later dropped to US$449
- 25 mhz fsb, 50 mhz clock speed odp price
- US$699, later dropped to US$599
- Odpr486 dx-25 price
- US$599
- 33 mhz fsb, 66 mhz clock speed odp486 dx
- US$799
- 33 mhz fsb, 66 mhz clock speed odpr486 d
- US$799
Lore & Background
Intel produced the i486 OverDrive processors as a means to upgrade existing personal computers without replacing the entire motherboard. Each OverDrive typically came in two variants: ODP and ODPR. The ODPR chips had 168 pins and functioned as complete swap-out replacements for existing chips. The ODP chips had an extra 169th pin and were designed for insertion into the 169-pin 487SX socket available in 486SX motherboards, which would disable the existing 486SX CPU. ODP chips would not work in pre-Socket 1 486 boards (168-pin, also known as Socket 0, the original 486DX socket) due to the extra pin. The ODP and ODPR labeling appeared in the CPU's model number, for example DX2ODPR66.
Models included versions with a 20 MHz front-side bus and 40 MHz clock speed, a 25 MHz FSB and 50 MHz clock speed, and a 33 MHz FSB and 66 MHz clock speed. Additionally, DX4 OverDrive versions were available with 25 MHz FSB and 75 MHz clock speed, and 33 MHz FSB and 100 MHz clock speed. Two P54 core Pentium-based CPUs were released for PGA 238 Socket 2/Socket 3-based systems, detailed under Pentium OverDrive.
Reader's Guide
The i486 OverDrive processors held significance as a targeted upgrade path for users of 486-based personal computers, allowing performance improvements without requiring a full system replacement. By incorporating features such as built-in voltage regulators, write-back cache, and integrated heatsinks, these chips addressed compatibility and thermal challenges that standard i486s might encounter in upgrade scenarios. The distinction between ODP and ODPR variants provided flexibility: ODPR chips served as direct drop-in replacements for existing CPUs, while ODP chips utilized the dedicated 487SX socket found in 486SX motherboards. The pricing structure, with initial costs ranging from US$549 to US$799 and subsequent price drops, reflected Intel's strategy to make these upgrades accessible. The later inclusion of Pentium-based OverDrive CPUs for Socket 2/Socket 3 systems extended the upgrade concept to newer platforms. The i486 OverDrive series thus represented a transitional approach to CPU upgrades, bridging the gap between full system replacements and simple processor swaps.
Did You Know?
- The i486 OverDrive processors included built-in voltage regulators, write-back cache, and built-in heatsinks.
- ODP chips had 169 pins and required a 487SX socket, while ODPR chips had 168 pins and worked as direct replacements.
- The 33 MHz FSB, 66 MHz clock speed OverDrive versions (both ODP and ODPR) were priced at US$799 each.
- Two P54 core Pentium-based OverDrive CPUs were released for PGA 238 Socket 2/Socket 3 systems.
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