The 5V FPU and SXLC arrived and I soldered them onto the Evergreen 486 SuperChip. The good news is that the chips are functional, that is, not DOA; the bad news is that the 5V SXLC2-40 suffered the same fate as the 3.6V SXLC2-50. Trying to use the L1 cache of the SXLC CPU causes the system to hang. So, I'm guessing there is some aspect of the Evergreen's onboard logic that is interfering with proper operation of an SXLC.
This leaves the SLC 25/50 or SLC 33 as the fastest options for this interposer. I was informed, unfortunately, that the SLC 25/50 is permanently stuck on 2x mode. This will greatly limit the front-side bus and performance. Does anybody have any data or anecdotal evidence of how far the Cyrix SLC 25/50 (not IBM varient) and Cyrix SLC 33 will overclock reliably? I will have the following scenarios to test once the SLC 25/50 chip arrives.
SLC2-25/50
CRYSTAL - FSB - CPU, where CPU = CRYSTAL/4*2*2
50 - 12.5 - 50
55 - 13.8 - 55
60 - 15 - 60
66 - 16.7 - 66
70 - 17.5 - 70
SLC33
CRYSTAL - FSB - CPU, where CPU = CRYSTAL/4*2
66.6 - 16.7 - 33.3
70 - 17.5 - 35
75 - 18.8 - 37.5
80 - 20 - 40
87.5 - 21.9 - 43.8
90 - 22.5 - 45
I doubt the SLC2 25/50 will be stable past 60 MHz and the SLC33 past 45 MHz. My SLC25 would only do 33 MHz stable, so it is possible 40 Mhz is the upper limit for the SLC33. My guess is that SLC2 25/50 can do 55 MHz reliably with a 13.8 MHz FSB and the SLC33 can do 40 MHz reliably, with a 20 MHz FSB. Which is the faster option?
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