william.richardson@canremote.uucp (WILLIAM RICHARDSON) (08/10/89)
The V20 is an excellent value for the money. For $10-$20 you can get a 7% improvement in speed + 80286 real mode instructions & 8080 compatability for CPM, the V20/30 are CMOS and run alot cooler that the 8088/86 versions from Intel & AMD. A reduced microinstruction code can mean the difference between BASIC & Assembler. Just the POST increase in speed for PCs' & XTs' is worth it! Try running a math/graphics intense program like F19 or FlightSim Side by Side with a standard 8088/86. I put a V30-8 in my model 30 and now get a norton SI of 4.3 from 1.8 that was standard. Has anyone noticed the new 80287/80387 from Witec? They claim 200% increase with the same clock rate on the 80287. Fun note: most ATs' run their Co-Processer at 2/3 the system speed! That can be fixed though, I'm running mine & 16Mhz on a 12Mhz AT ! --- ~ EZ-Reader 1.20 ~ -ex * QNet 1.03a3: CanConfMail: . HQBBS / ~ Toronto ~ Canada ~ 416y566y1765
chasm@attctc.Dallas.TX.US (Charles Marslett) (08/12/89)
In article <89080907301922@masnet.uucp>, william.richardson@canremote.uucp (WILLIAM RICHARDSON) writes: > . . . Has anyone noticed the new 80287/80387 from > Witec? They claim 200% increase with the same clock rate on the 80287. I don't know about such from Weitek, but a startup company (the founders are from Weitek, if I remember my rumors correctly) called IIT has started makeing 287 and 387 clones. I got one! And it is fast -- one funny, though, is that ... > Fun note: most ATs' run their Co-Processer at 2/3 the system speed! > That can be fixed though, I'm running mine & 16Mhz on a 12Mhz AT ! As you mentioned, a signal can be used to divide the incoming clock (usually twice the CPU clock or equal to the CPU clock) by 3 before using it in the 287 -- the IIT chip divides the clock by 2 rather than by 3, so you get an additional speedup if the box runs with the divide-by-3 enabled. I wrote a benchmark suite (that includes one demo written by IIT programmers and it indicates you can get anywhere from a few percent improvement to about 4x depending on the type of code (if you load the FPU and bang away -- like my fractal demo -- it runs away with you, but if you just do the usual plodding C code -- load, add, store sequences -- then you'll get something more like a 10 or 20% improvement over a similar speed 287). Most programs are somewhere in between. > --- > ~ EZ-Reader 1.20 ~ -ex > > * QNet 1.03a3: CanConfMail: . HQBBS / ~ Toronto ~ Canada ~ 416y566y1765 =========================================================================== Charles Marslett STB Systems, Inc. <== Apply all standard disclaimers Wordmark Systems <== No disclaimers required -- that's just me chasm@attctc.dallas.tx.us