cramer@kontron.UUCP (Clayton Cramer) (03/22/86)
I recently purchased a kit for my home PC called *Fast88* from a Fremont company called MicroSpeed. This kit provides a substantial performance improvement for the IBM PC, XT, and *some* of the PC clones at a very cost-effective price. The kit includes: an 8 Mhz 8088; a board containing 6.1, 6.7, and 7.4 Mhz 8284A clock chips; an external switch for switching from 4.77 Mhz (the normal PC/XT speed) to the jumper selectable high speed, and a "hard reset" button that is effectively equivalent to switching the power on and off; and a few pieces of mounting hardware to locate the board on the back of the PC/XT system unit (this is *not* a board that plugs into the mother board. The instructions claim that 6.1 Mhz can be used on just about all PCs, 6.7 Mhz on all systems with 200 nanosecond memory, and 7.4 Mhz on all systems with 150 nanosecond memory. (Standard speed of the PC is 4.77 Mhz.) To begin with, I have an antique IBM PC -- 16K RAM chips on the mother board, and a five digit serial number. However, all the RAM in my system is either 200 nanosecond or 150 nanosecond. Installation is pretty easy, and the documentation is quite clear. It took about fifteen minutes to install. At 6.1 Mhz my PC worked perfectly. At 6.7 Mhz (a speed that should have worked) the memory was untrustworthy -- everything worked for a few minutes, then characters started to change in a mildly random manner. Finally the system locked up. At 7.4 Mhz it didn't work at all. I called technical support at MicroSpeed, and the person I talked to indicated that the problem was probably my DMA controller chip (8237A). As he explained the type of failure this chip is prone to, I realized that non-reproducible memory problems that I've had with my PC for the last several months were probably caused by the DMA controller chip as well. (Unfortunately, the chip is soldered into the motherboard on my PC, and is therefore not easily replaced.) Even at 6.1 Mhz, the performance improvement is dramatic. A stopwatch isn't necessary to see the improvement -- just about any program you run is clearly faster. The first test I ran was to load in a book I'm writing into the Volkswriter Deluxe word processor. At 4.77 Mhz it takes 192 seconds. At 6.1 Mhz it takes 150 seconds. (About 28% better.) The second test was to compile and link a C program with the Microsoft C compiler. At 4.77 Mhz it took 159 seconds. At 6.1, 130 seconds. (A 22% improvement.) The third test was running the CHKDSK command of PC-DOS. This went from 14.5 to 12.7 seconds. (A 14% improvement.) The fourth test was executing the PC-DOS command TYPE README.DOC. This reduced from 16.6 to 12.7 seconds. (A 31% improvement.) The fifth test was scrolling through a small file using Volkswriter Deluxe. This went from 3.1 to 2.4 seconds. (A 29% improvement.) MicroSpeed warns that the PC-DOS FORMAT and DISKCOPY programs and certain types of copy protection schemes will not work correctly at higher speeds. In my limited testing, I have not found any programs that don't work. However, the *Fast88* kit allows you to change from the standard speed to the higher speed and back *while programs are running*, so you don't have to reboot the system if you need to use a program that only runs at 4.77 Mhz. I have no financial interest in MicroSpeed -- I wish I did.
keifer@uiucdcs.CS.UIUC.EDU (04/05/86)
So how much does a 20-30% increase in speed co$t?
cramer@kontron.UUCP (Clayton Cramer) (04/11/86)
> > So how much does a 20-30% increase in speed co$t? I think my original posting failed to list a price for the MicroSpeed kit. List is $129 -- Fry's Electronics sells it for $119.