What program do you use for X2 mode? I use the attached one.

I use cyrix.exe. It's a one-stop-shop that most people use.

Are you able to De-Turbo, Re-Turbo with your SXL at 2x, ideally with Landmark running? If yes, could you list the system specifications?

I probably never tried DeTurbo. Also I don't have it setup so can't test it at the moment.

Try the cache486 program. It has quite some options.

kixs wrote on 2024-12-06, 08:54:

I probably never tried DeTurbo. Also I don't have it setup so can't test it at the moment.

Try the cache486 program. It has quite some options.

cyrix.exe and cache486.exe have similar options. I still get system freezes if I de-Turbo after having used cache486. I've tried this on 3 motherboards, all freeze.

Can you list the motherboards? So I can check if I have any other.

Tested on:

DTK PEM-4036YB
Biostar MB-1340C -CH
AMI Mark V Baby Screamer

All are using a PS/2 mouse with KBC mod. Thinking it was the PS/2 mod, I also ran the Biostar MB-1340C-CH with its original KBC and BIOS, but same issue occurred: de-Turbo causes hang in SXL 2x mode.

EDIT: Tested the AMI Mark V Baby Screamer again, but this time the Turbo/de-Turbo switch worked fine.

Is this the ordinary SXL2 or the 66Mhz version? I have a few other 3-486 boards, mainly VLB.

I have noticed other non-intel "not being slow enough" when deturboed but not sure what's going on. I thought at first, the turbo function of the board was failing to deactivate L1 like it did on the intel, but cachechk said it did. Last one I was messing with was my UMC U5S, that's like ~1.5x faster than an i486sx normally but over 4x faster in turbo mode. But thinking about a 386 class board, it probably has no idea it's supposed to turn an L1 on chip cache off. Started me wondering if there's any other mode change. For instance on that board 386 apps no longer worked right on intel in deturbo, but I was able to launch one or two on the U5 in deturbo.

I will have to investigate behaviour on my TI486SLCs when I get a PT-319A going.

Turbo modes in general seem all over the place board to board. Some seem to try for a 5170 8mhz compatibility speed, some still trying for 4.77ish XT on AT class.

I was testing the SXL2-66. I tried to de-turbo with operating speeds as low as 50 MHz, but still hangs when in 2x mode.

Does de-turbo work with L1 cache disabled? - L1 disabled in BIOS and cyrix.exe ?

deleted - because that's not what the conversation is about.
I misunderstood - sorry.

PiotrUU wrote on 2024-12-07, 16:40:

exp-4349 motherboard + Ti486sxl@168 pin cpu in x2 mode turbo button works fine […]
Show full quote

exp-4349 motherboard + Ti486sxl@168 pin cpu
in x2 mode turbo button works fine

si8@50 = 79.4 / 10.6 Turbo / deTurbo
LM6@50 = 153-160 / 40

si8@25 = 41.1 / 8.4
LM6@25 = 105 / 27

note: when the processor is in x2 mode and you run the NNSI program ( v 0.60.45 ) - the program will show cpu@50Mhz and switch to 1x mode.

Isn't the EXP-4349 one of the few motherboards which has built-in support for the PGA168 SXL2? I'd hope the turbo/deturbo worked on that board. It is the boards without this specific SXL2 support that I'm investigating.

MikeSG wrote on 2024-12-07, 09:39:

Does de-turbo work with L1 cache disabled? - L1 disabled in BIOS and cyrix.exe ?

If I run cyrix.exe -e- to disable the L1 cache, then de-turbo, I still get a hung system.