Now Im getting somewhere! 😀

I tested the "new" Lucky Star LS486E C1 motherboard to see what it could do, 60 MHz seems to work well in DOS at least. The LS486E isnt as fast clock for clock as the MG V1.1A (M921 clone) but at 180 MHz it gets some decent scores.

AMD 5x86 3x60 MHz Speedsys.

AMD 5x86 3x60 MHz Cachechk.

AMD 5x86 3x60 MHz PCPbench VGA mode: 26.7 FPS

AMD 5x86 3x60 MHz PCPbench Mode 100: 11.3 FPS

I tested to run Quake 1.06 and 1.08 from my bench disk with this LS486E, the AMD 5x86 at stock speed and with relaxed memory and cache timings and got the eaxct same page fault as with my Asus PVI-486SP3 system. The same Quake installations worked with another of my LS486E motherboards some weeks ago so Im starting to think these Quake installations have gotten corrupted. I copied these to the Asus PVI-486SP3 system from the bench disk while I installed the (working) Quake 1.01 installation directly from disc. I need to restest the installations installed on the bench disk with the LS486E motherboard that worked with them before to confirm.

If I would use 5V Im sure I could get 200MHz going but I use a socket 7 cooler which only is placed ontop of the AMD 5x86 CPU without beeing secured at all, perhaps its not a good idea to use 5V under such conditions. 😀

best to use a socket 7/370 cooler with fan and thermal paste. Try to determine the minimum voltage required at 180 MHz for the chip to run stable in DOS Quake as well as with some demanding Win9x benchmarks, such as 3DWinBench 97, or GLQuake/WinQuake running in loop for an hour. I too was once on a quest for an Am5x86 at 180 MHz, however benchmarks in Windows killed the prospect of stability. In DOS, I was able to get Quake running at 180 MHz, but if I recall correctly, Win9x caused great anguish. Running the CPU beyond 4 V might not be ideal for longevity.

feipoa wrote:

best to use a socket 7/370 cooler with fan and thermal paste. Try to determine the minimum voltage required at 180 MHz for the chip to run stable in DOS Quake as well as with some demanding Win9x benchmarks, such as 3DWinBench 97, or GLQuake/WinQuake running in loop for an hour. I too was once on a quest for an Am5x86 at 180 MHz, however benchmarks in Windows killed the prospect of stability. In DOS, I was able to get Quake running at 180 MHz, but if I recall correctly, Win9x caused great anguish. Running the CPU beyond 4 V might not be ideal for longevity.

The Lucky Star LS486E supports 3V, 4V and 5V, I hope the 3V setting is 3.3+V but it seems in any case to be too low to run my other (much worse) AMD 5x86 at stock speed 100% reliable. I have been using 4V when overclocking on these boards so far which is enough for even the "bad 5x86 to be able to run stable at 160 MHz.

I do not have Windows installed on this "bench disk" but I will build a system around this board when a desktop case I bought gets here. I will install Windows and with luck a working Quake 1.06 installation. If I can not get away with running 180 MHz I will settle for 160 MHz which I hope to be able to run at the 3v setting, if not with this CPU then perhaps with one of the two others I have incoming.

One great thing with this motherboard is that the VRM heatsink is still cool enough to touch even when running the CPU at 180 MHz with 4V.

Any idea how good overclockers are AMD486DX5-133W16BGC over the usual ADZ ones? Would like to get one to work @200MHz 😉

kixs wrote:

Any idea how good overclockers are AMD486DX5-133W16BGC over the usual ADZ ones? Would like to get one to work @200MHz 😉

I have a few, but wasn't even able to get them stable at 180 MHz. It is really hit or miss with these Am5x86 chips for 180+ MHz operation. I could not see any trend indicating one type better than the other for 180+ MHz. I keep reading on here than the ADW chips don't overclock as well as the ADZ chips, however there was an ADW chip demonstrated stable at 200 MHz in Windows and running numerous benchmarks.

Even I have less good experience with ADW chips. They all work fine at 160 but none would boot at 180. While I have two ADZ that both boot at 180 but only one that is stable at 180 and also boots at 200. I guess it's a matter of luck - like always.

Have any of you vintage over-clockers tried putting one or two Polymer caps on the motherboard's +5v power to see if you can improve stability at the higher FSBs?
Should be low uF so as to not screw-up boot timings with an ESR somewhere around 0.010 ohms.
.

Aren't such caps already in place on the motherboard itself?

feipoa wrote:

Aren't such caps already in place on the motherboard itself?

No.
Some 486 and older boards didn't have any Lytic caps at all.
Those that did usually had general purpose caps rather than low ESR.
.
One or two low ESR caps would reduce the amount of ripple in the power plane thereby giving the IC chips (including the RAM and MCH/chipset) a more stable voltage to work with. Or rather a 'cleaner' DC power voltage.
A chip with cleaner power is more likely to be stable near it's extreme limits.
.

sunaiac wrote:

For reference, here are my unoverclocked (except last line) results, on a MB8433 v2.0, with 32MB FPM RAM, and an S3 Trio 64 : […]
Show full quote

For reference, here are my unoverclocked (except last line) results, on a MB8433 v2.0, with 32MB FPM RAM, and an S3 Trio 64 :

Of course this table will look better when I've found a stable 133MHz DX4 from intel 😀

Man how could you set a DX4 to go as a DX5 with BUS at 66 but the CPU "only" at 133?
I mean, isn't the multiplier inside the CPU for 486s? Then, how did you convince the CPU's multiplier to go 2x instead of 3x ??

Thanks.

Some Intel dx4s support 2x and 3x multipliers, for official 2x50mhz or 3x33mhz speeds.

sunaiac wrote:

Some Intel dx4s support 2x and 3x multipliers, for official 2x50mhz or 3x33mhz speeds.

Wow but this is FANTASTIC!
Setting a DX4 100 at 50x2 instead of 33x3 is FANTASTIC!

Many, this is a missed dream for me when I was a kid!!!!

How would you "set" it at 2x? Just setting the BUS at 50? How do you know if your DX4 CPU does support both 2x and 3x? Serial number or something?
Thanks

486 multipliers selection is independent of bus speed.
The final multiplier is hardcoded in the CPU.
Basically, the CPU detects if your motherboard set the value of the multi to off or on. If off, you get the first hardcoded multiplier. If on, the second.

So dx2s usually have 1x and 2x, Some AMD get 2x and 3x
Dx4s 2x and 3x.
Some AMD dx4s 3x and 4x.

Etc...

Intel CPUs are identified by a sspec number.
For example sk096 or sx750...
If you type this on Google you'll get a cpu-world link. Dx4s that support 2x multiplier are indicated there.

thanks!
and how do I set the multi as off on the mobo?

That is motherboard depend and usually done through jumpers.

sunaiac wrote:

That is motherboard depend and usually done through jumpers.

You just opened up a new world for me! Thanks!!!

DX2 chips do not support 1X. Only 2X. There is only one socket3 chip that supports 1X, that is the cx5x86 ,and it must be done with software.

Anonymous Coward wrote:

DX2 chips do not support 1X. Only 2X. There is only one socket3 chip that supports 1X, that is the cx5x86 ,and it must be done with software.

ok, thanks!

Kixs, were you ever able to run windows 95 at 180 MHz?

That’s NOT a 486 but 5x86.
Nice job however. I never tried 180mhz.
I was able to get 160mhz stable.
AMD 5x86@160mhz., Media Vision PAS16. ( Win 95 )

What bios clock and timing settings are you using ?
Can you play MP3’s ?