Processor speed comparisons
CAUTION: The use of some high speed processors requires a careful consideration of both voltage variations and socket differences intend to provide information about this later, unless I can find another site with a good description of these considerations. Also, many of these hardware options require matching software upgrades in order to obtain performance gains.
Processor speed comparisons
Reply PowerBoard and TurboBoard Planar Upgrades
Reply Corporation is no longer in business. For a number of years, Reply manufactured replacement planar upgrades for a number of PS/2 models. The ones of interest here were made for the Model 60, 65, and 80 which all shared the same physical structure and also had many common parts. I am not familiar with the differences between the TurboBoard and the Power Board. Since I personally have one of the PowerBoard units and the documentation, the following comments will be restricted to the Power Board. Although these units were originally advertised as upgrade able to utilize the 133 MHz 486 products, the manual and my experience indicates that the supported processor limit is 100 MHz!
Features of the PowerBoard are:
Features of the TurboBoard are:
A photo of the TurboBoard is available on Tam Thi Pham's web-page.
Kingston McMaster BusMaster Adapters
There are several versions of this adapter available. The ones of interest have a 32-bit interface and provide a 168-pin 486 socket and can be used to upgrade either a 386 system or a 286 system. (There was an earlier version called an AOX McMaster which provided an upgrade adapter from a 286 system to a 386 system. I believe that the AOX company was bought by the Kingston Technology Corporation. This version is a 16-bit adapter and would not be appropriate for the 8580!.)
Like most Kingston adapters, different names exist for various configurations depending on the processor installed! For example, I have seen them described as MC33PD/xx, MC25PS/xx, MC50PD/xx and Kingston also lists MC33PS, MC66PD and MC133PD as discontinued models. Fortunately, the Kingston Technology Corporation still provides information on these adapters at their web site. Installation Guides for the MC25xx and MC33xx models are available at McMaster Guide #1 and for the MC133PD model at McMaster Guide #2. The ADF files and utility diskettes are available from McMaster software. Installation Guides for the MC25xx and MC33xx models are available at McMaster Guide for MC25/33/50/66 and for the MC133PD model at McMaster Guide for MC133PD. Also download ADF files MICROADF.EXE and the utility diskette MCMR236.EXE.
There are jumpers J100 for designation of DX (1-2) or SX (2-3) processors and J801 for non-IBM SIMMs (1-2) or IBM SIMMs (2-3). For the more adventurous, the 33 MHz adapters have both 25 MHz oscillators (Y100) and 33 MHz oscillators (Y101), whereas the 25 MHz adapters lack the oscillator at Y101. Next to these oscillators is a hardwired jumper (J102) with a soldered link between (1-2) on the 33 MHz adapter and (2-3) on the 25 MHz adapter.
A possible unofficial upgrade may have been discovered by Jim Shorney who was feeling adventurous and took a 25 MHz adapter and installed a 32 MHz oscillator in Y101 and replaced the hardwired jumper with a jumper block and connected (1-2). The result was an adapter that worked with a base rate of 32 MHz and could potentially support one of the various 5x86-133 upgrade processors. Jim advises that he used an oscillator from one of the newer 8570 planars, as the oscillator physical size and pin configuration does not match the size and location of the more common larger DIP style oscillators. However, he has since reported that the upgrade has not been very reliable, but the cause has not been identified. I would appreciate hearing from anyone else who has experience with this or similar changes.
An extract from a subsequent Usenet posting to comp.sys.ibm.ps2.hardware
by Jim Shorney follows:
Many people have asked about the empty white connector (upper right corner). This is identified as a Local-Bus Video Socket and there is no know module to use this slot. It is assumed that this was another feature that was announced, but never implemented. Anyone with information on this is asked to contact me.
Kingston Processor Upgrades
Kingston also produced several other interesting upgrades involving replacement of the processor with a faster processor on a small daughter-board which is inserted into the 386 processor socket. They consisted of:
Kingston 486/NOW! (Part Numbers 486/33PD3, 486/33PS3 and 486/25PS3)
These upgrades provide a 486 processor with clock speeds of either
25MHz or 33MHz. The PD models includes a math co-processor and the PS models
do not. There are also different part numbers for the Model P70 which might
not work correctly in the Model 80. If you are interested in more details,
NOW! Installation Guide is still available at the Kingston support
Lightning/486 (Part Number 486/BL66)
This upgrade consisted of the IBM Blue Lightning processor (486DLC processor
running internally at a clock-doubled rate of 66MHz). If you are interested
in details, the Lightning/486
Installation Guide is still available at the Kingston support site.
IBM "Daughter" Processor Upgrade Cards
IBM Planar Upgrades
IBM sold a replacement planar, but it was an expensive upgrade and not
many of these are likely to be located.
Cyrix 486DRx2 16/32 and 20/40 and 25/50
Cyrix produced a family of 486 chips which provided a 486 processor
with clock-doubled speed internally for each of the three different 8580
motherboards. They claim that it is necessary to match the correct speed.
Software (driver) is required.
Texas Instruments TX486DLC/E - 40GA
Texas Instruments manufactured a direct replacement 486 processor with
the 386-style 132-pin PGA socket configuration. Software (driver) is required
in order to activate the internal cache and gain the performance advantage
of using this chip. Since this chip runs at the same speed as the planar,
the gain is limited.