Cyberstorm MKII, 060 and overclock

Hi All.

I´m doing some research to give my old A4000 a push forward (like changing caps and some other reworks).

My doubts come with a Cyberstom MKII that I have, with an rev.1 060 that always runs fine clocked to 66 Mhz for some years now. (obviously plus heatsink, fan and no Cyber-SCSI controller installed at all).

My doubt is if this board tolerates well higher clock frequencies (say 80 Mhz) If I manage to get one of those rev.6 060s (mask 71E41J or some such). any clue ?

My current RAM config is with 4x32 MB 60 ns. SIMMS .

Thanks in advance to all.

Martin.

My MKII works fine with 80MHz but problem is to find good memory for this clock. With 72MHZ works with 60ns. I bought 75MHz and check it this Saturday.

Ok , thanks for the info. Now I remeber that someone told me something like that some time ago.

I assume that is more a matter of luck that a 60 ns. SIMM tolerates those rates or not, aren't it ?

Beacause as far as I know 72c SIMMs with rates below 60ns are ultra-rare and really hard to find (Don't know really but never seen one of those anyway).


Lets wait your testing and see, please tell me.

Mine will do 75MHz with 60ns (Crucial/Micron) RAM and a Rev 6 CPU. (Watch the voltage regulator, they can get really hot.) However, above 66MHz you might encounter issues with DMA devices. The MK-II SCSI-kit is almost out of the question, Fastlane and 4091 might also become problematic. (Especially in conjunction with a Picasso IV, which should have the latest bridge revision.) Ultimately, after lots of testing, I settled at 64MHz for reliability, and to keep the DENEB running happy in DMA mode.

Ok, thanks also for the info , In my case the troubles with any scsi controller doesn't matter, as I dont use scsi at all nowadays (thats and old story about crap cables, faulty devices, etc... , making me not wanting to mess with anything scsi related for a long time :|).

But is interesting your statement about the picasso IV as I also have one, however as far as I know, It is suited with the last revisions of those bridge chips (there are two if i remember correctly) and firmware.

So, actually dont use any other DMA intensive z3 board (I have got a fastlane also but unused for years), maybe I can give it a try on overclok (well, after finding a rev6. 060, hehe).

And finally for the regulator getting hot, one thing that will help , again if i remember corecctly, is that mine's is a bit over spec on amperage rating , I'll have to compare ratios again between form factor specs one and this one (my CS MKII is an 040 reworked to 060).