The page contains support information for the Pentium® Overdrive® Processor. Support for other OverDrive® processors can be found at:
Q1: I have installed a 120/133 MHz Pentium® OverDrive processor and my system will not boot. Why?
Some 60 - 66 MHz Pentium processor - based systems need an interposer socket to stabilize and filter some signals going to and from the processor. The part can usually be installed by most endusers. It is inserted between the socket on the motherboard and the OverDrive processor.
The interposer socket is available by calling our technical support centers.
Please have your BIOS revision and the AA number off your motherboard ready when you call.
Q2: Do I need to set jumpers for the Pentium OverDrive processor?
All Pentium OverDrive processors for Pentium processor - based systems are designed to simply replace the original processor with no jumper changes required if used as recommended.
The 63 or 83 MHz Pentium OverDrive processor for i486™ processor - based systems usually require jumper changes. We recommend that you consult your system manual for what jumpers to change and their locations.
If you cannot find the jumper settings on the Web site, we encourage you to contact the system manufacturer or supplier.
Q3: I have installed my 83 MHz Pentium OverDrive processor and my computer locks during POST. Why?
A few systems have a BIOS that will not correctly identify the processor or test the PC now running at the new higher speed. We urge you to check with the manufacturer for compatibility of your BIOS revision with the Pentium OverDrive processor and obtain an update if available.
Q4: I have installed my Intel OverDrive processor and see no performance increase. Why?
If you're relying on third-party benchmark results, we invite you to discuss the results with the publishers as to what is being measured. Some applications rely on frequent data transfer of information into and out of memory from peripherals (I/O). The performance of these data transfers is accomplished by the motherboard and the peripherals, not the processor. If you are using system boot time or software load time as testing criteria, these are I/O intensive operations and are not heavily affected by the addition of an OverDrive processor. If you are not pleased with the performance of the OverDrive processor, we recommend that you contact the dealer where you purchased the OverDrive processor for a refund.
Q5: My BIOS doesn't recognize the Pentium OverDrive processor speed correctly. Why?
The BIOS in your system may have been created before information about the current OverDrive processor speed was available. The BIOS is only able to report processor speeds that the motherboard designer included in BIOS design. Thus, it may not have the correct "speed bin" within it and will issue an erroneous speed rating. If your system is otherwise running correctly, this may be a cosmetic issue and not worth the effort to upgrade the BIOS.
Q6: I have installed my OverDrive processor into my computer and now I get Windows 95 and Windows 3.1/3.11 errors. Why?
If you're getting multi-colored lines or corrupted video on the screen after a Pentium OverDrive processor is installed, the video driver may be suspect. If you do not get these symptoms in "safe mode" or with the internal cache disabled, we recommend that you install the Windows or Windows 95 driver. Some video system adapters or drivers will not run at the new higher speed. We recommend that you check with the manufacturer of the video adapter for compatibility of the adapter and possible driver updates.
Q7: My SCSI CD-ROM doesn't seem to work now that I have the Pentium OverDrive processor installed. Why?
Intel has found that some SCSI adapter drivers and/or BIOS will not work at higher processor speeds. Many of these issues can be solved by updates to the driver or BIOS from the manufacturer.
Q8: I have installed my 83 MHz Pentium OverDrive processor and my floppy drive does not seem to work. Why?
Some motherboards use an incorrect write-back cache mode implementation utilizing the "SIS 85C471" controller chip. The most common symptom is not recognizing floppy drives correctly. This issue can be resolved by installing an interposer socket between the OverDrive processor and the socket on the motherboard. These interposer sockets may be obtained through our technical support centers.
Q9: I could not find my computer listed on your Web site. How do I know if it's compatible?
If your system is not found in the Upgrade Guide, we recommend you contact the system manufacturer or supplier to verify compatibility and recommend an upgrade processor.
Q10: I have installed the OverDrive processor and my computer seems to boot or run slower. Why?
The internal cache of the processor may be disabled. Check the status of the internal cache in CMOS setup and enable the cache if necessary.
Q11: There are two versions of the IntelDX4™ OverDrive processor, BOXDX4ODP100 and BOXDX4ODPR100. What is the difference between these two processors?
The two types of IntelDX4 OverDrive processors are designed to upgrade different types of i486™ processor-based systems:
BOXDX4ODPR parts have 168 pins and are designed to upgrade i486 DX processor-based systems. In most cases, the i486 DX processor is removed and replaced with the OverDrive processor. These parts use the same jumper settings as the i486 DX processor.
BOXDX4ODP parts have 169 pins and are designed to upgrade i486 SX processor-based systems. The majority of these systems include a "keyed" upgrade socket with one extra pinhole to ensure correct orientation of the OverDrive processor. This socket may be a separate, empty socket into which the OverDrive processor is installed, or it may be the same as the i486 SX processor socket, in which case the processor is removed and replaced with the OverDrive processor. These parts use jumper settings specific to the OverDrive processors and the old i487 SX math CoProcessors. Both pinout variations are available in either 75 MHz or 100 MHz versions. They are designed to upgrade 25 MHz and 33 MHz i486 processors, respectively. The processor die and performance of the pinout variations of OverDrive processors are identical.
The IntelDX4 OverDrive processor has been discontinued and is no longer available from Intel. Availability is limited to existing stock at local dealers, on the Internet, or by mail-order.
Q12. Where can I get support for IntelDX2 OverDrive processors?
These products were discontinued by Intel Corporation as of April 1996.
Effective March 3rd 1997, Intel ended support of the IntelDX2 OverDrive Processors. This includes the following parts;
BOXODPR486DX25 old ver.
BOXODP486SX25 old ver.
BOXODPR486DX33 old ver.
BOXODP486SX33 old ver.
A complete list of documents is available from the Technical Documents page of support.intel.com. From the Technical Documents page, select OverDrive® Processors.
This applies to: