wirerogue wrote on 2024-01-27, 22:17:

greetings, i just replaced the intel dx2-66 with a dx4-100 overdrive (DX4ODP100) in my winpro 486e. now my board is reporting ba […]
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greetings,
i just replaced the intel dx2-66 with a dx4-100 overdrive (DX4ODP100) in my winpro 486e.
now my board is reporting bad sram, cache disabled during post.
it was working good prior to this. i even ran the cachechk utility when the dx2-66 was installed and everything was good.
it works well otherwise.
any suggestions, always appreciated.
thanks.
here's the board. daewoo 9916522802
daewoo.9916522802.jpg
here's a picture of the cache chip which was recommended from my manual.
mt5c6408-20.png

And with the DX4 and no cache everything is fine? Did you stability test it?

CoffeeOne wrote on 2024-01-27, 22:33:

wirerogue wrote on 2024-01-27, 22:17:

greetings, i just replaced the intel dx2-66 with a dx4-100 overdrive (DX4ODP100) in my winpro 486e. now my board is reporting ba […]
Show full quote

greetings,
i just replaced the intel dx2-66 with a dx4-100 overdrive (DX4ODP100) in my winpro 486e.
now my board is reporting bad sram, cache disabled during post.
it was working good prior to this. i even ran the cachechk utility when the dx2-66 was installed and everything was good.
it works well otherwise.
any suggestions, always appreciated.
thanks.
here's the board. daewoo 9916522802
daewoo.9916522802.jpg
here's a picture of the cache chip which was recommended from my manual.
mt5c6408-20.png

And with the DX4 and no cache everything is fine? Did you stability test it?

running with no cache is totally stable.
i changed the motherboard jumpers to 128kb and it seems to work for now.
i'll wait until i pull the board out again and try reseating all the sram again.
thanks.

wirerogue wrote on 2024-01-28, 00:06:

running with no cache is totally stable. i changed the motherboard jumpers to 128kb and it seems to work for now. i'll wait unti […]
Show full quote

CoffeeOne wrote on 2024-01-27, 22:33:

wirerogue wrote on 2024-01-27, 22:17:

greetings, i just replaced the intel dx2-66 with a dx4-100 overdrive (DX4ODP100) in my winpro 486e. now my board is reporting ba […]
Show full quote

greetings,
i just replaced the intel dx2-66 with a dx4-100 overdrive (DX4ODP100) in my winpro 486e.
now my board is reporting bad sram, cache disabled during post.
it was working good prior to this. i even ran the cachechk utility when the dx2-66 was installed and everything was good.
it works well otherwise.
any suggestions, always appreciated.
thanks.
here's the board. daewoo 9916522802
daewoo.9916522802.jpg
here's a picture of the cache chip which was recommended from my manual.
mt5c6408-20.png

And with the DX4 and no cache everything is fine? Did you stability test it?

running with no cache is totally stable.
i changed the motherboard jumpers to 128kb and it seems to work for now.
i'll wait until i pull the board out again and try reseating all the sram again.
thanks.

sometimes there are edge cases where the cache timings are stable with slower CPUs but unstable with faster ones even when the actual bus speed doesn't change, I'd try swapping to -15ns rated SRAM if you have any available to try

maxtherabbit wrote on 2024-01-28, 02:07:

wirerogue wrote on 2024-01-28, 00:06:

running with no cache is totally stable. i changed the motherboard jumpers to 128kb and it seems to work for now. i'll wait unti […]
Show full quote

CoffeeOne wrote on 2024-01-27, 22:33:

And with the DX4 and no cache everything is fine? Did you stability test it?

running with no cache is totally stable.
i changed the motherboard jumpers to 128kb and it seems to work for now.
i'll wait until i pull the board out again and try reseating all the sram again.
thanks.

sometimes there are edge cases where the cache timings are stable with slower CPUs but unstable with faster ones even when the actual bus speed doesn't change, I'd try swapping to -15ns rated SRAM if you have any available to try

Thanks, I'll give that a shot

With full cache does the DX4 run stable with a 25mhz FSB? If not
There was an edge case that Intels own DX4s were notoriously incompatible with certain motherboard/bios configurations.

Occasionally if you can set writethrough/writeback it may help , other times a bios update helps.

As odd as it may seem one old socket 1 board I had would work with the early 8kb AMD DX4 but not the Intel DX4

Intel missed the boat in some ways on the dx4 and p24t overdrives.

Yes, and the layout of that board is suboptimal.
SRAMs are far away from CPU.

Try 25 MHz. If that works, replace your SRAMs with 15ns, starting with the tag ram.
But basically 20 ns already should be enough for 2-1-1-1 @ 33 MHz. However, some CPUs may be more pesky with the timings. (In this respect I just remember Cx5x86 is worse than Am5x86.)