A little update 2023-08-24:

Changed the oscillator to 60Mhz (= 286@30MHz).

After a min or two it hangs. It seems the memory it at fault. 1WS solves this. But negates any speed advantages as it acts slower then 25MHz with 0WS.

Does anyone have faster SIMMs - like 45 or 50ns?

Photos:

kixs wrote on 2023-07-10, 23:14:

Anyways... to the benchmarks... Text version first in case of photos disappearing...

You could prevent pictures from disappearing by uploading them directly to VOGONS 😉

do you consider soldering a 25mhz rated CPU ?
good chance you are limited by the 20mhz one.

I don't have the skills. But so far the memory was the limit.

Those are really impressive scores! Definitely deep into 'decently fast 386' territory. 😀

monster!

Good values.
But really why don't you upload the pictures to Vogons? A lot of old posts on Vogons looks very ugly, because the pictures are missing.

kixs wrote on 2023-07-10, 23:14:

After many years of delaying... now is the time for the second round of 286 to the Max :D […]
Show full quote

After many years of delaying... now is the time for the second round of 286 to the Max 😁

Link to the first 286 to the Max thread Kixs's 286 to the Max

System info/config:

Motherboard: Octek Fox II Rev 3.4 with Harris 80286-20; HT12/a chipset
FPU: Cyrix 287XL+
Memory: 2x 1MB 60ns SIMM runs with 0-wait states
VGA: Tseng ET4000AX ISA

Oscillator clock: 58MHz == CPU@29Mhz

At this speed some active cooling is required. I used 12cm case fan to cool the motherboard in area of memory and CPU. Without it there were instabilities - warm room temperature doesn't help (26 degC).

I actually run out of incremental oscillators. After 58MHz I only have 66Mhz. My guess is the 60Mhz should still work fine.

Anyways... to the benchmarks... Text version first in case of photos disappearing...

Norton System Information: 22.8
Landmark System Speed Test 6.00: CPU: 45.90 | FPU: 37.68
Checkit 3.0: Dhrystones: 7533 | Whetstones: 999.9K
NSSI: Dhrystones: 7315 | Whetstones: 1112K
Comptest 2.60: Max MEM: 14068 KB/s | Drys. 7862.9 | Whetstones: 721.4K
PMIPS: 4.7
Celem Cache Test: 763 (lower is better)
Dr. Hardware 3.7: Hardstones: 6813 | Softstones: 1004 | RAM: 14.09MB/s | Bus: 5.15MB/s
3DBENCH 1.0: 12.0
WOLF3D Bench: 19.8

To do:
run other benchmarks
try other FPUs
try other VGA cards
get faster oscillators 😉
try to mod other motherboards with socket for easy replacing oscillator

I guess old habits die hard 🤣

CoffeeOne wrote on 2023-07-12, 20:39:

Good values.
But really why don't you upload the pictures to Vogons? A lot of old posts on Vogons looks very ugly, because the pictures are missing.

kixs wrote on 2023-07-10, 23:14:

After many years of delaying... now is the time for the second round of 286 to the Max :D […]
Show full quote

After many years of delaying... now is the time for the second round of 286 to the Max 😁

Link to the first 286 to the Max thread Kixs's 286 to the Max

System info/config:

Motherboard: Octek Fox II Rev 3.4 with Harris 80286-20; HT12/a chipset
FPU: Cyrix 287XL+
Memory: 2x 1MB 60ns SIMM runs with 0-wait states
VGA: Tseng ET4000AX ISA

Oscillator clock: 58MHz == CPU@29Mhz

At this speed some active cooling is required. I used 12cm case fan to cool the motherboard in area of memory and CPU. Without it there were instabilities - warm room temperature doesn't help (26 degC).

I actually run out of incremental oscillators. After 58MHz I only have 66Mhz. My guess is the 60Mhz should still work fine.

Anyways... to the benchmarks... Text version first in case of photos disappearing...

Norton System Information: 22.8
Landmark System Speed Test 6.00: CPU: 45.90 | FPU: 37.68
Checkit 3.0: Dhrystones: 7533 | Whetstones: 999.9K
NSSI: Dhrystones: 7315 | Whetstones: 1112K
Comptest 2.60: Max MEM: 14068 KB/s | Drys. 7862.9 | Whetstones: 721.4K
PMIPS: 4.7
Celem Cache Test: 763 (lower is better)
Dr. Hardware 3.7: Hardstones: 6813 | Softstones: 1004 | RAM: 14.09MB/s | Bus: 5.15MB/s
3DBENCH 1.0: 12.0
WOLF3D Bench: 19.8

To do:
run other benchmarks
try other FPUs
try other VGA cards
get faster oscillators 😉
try to mod other motherboards with socket for easy replacing oscillator

imgur is a blight frankly

very cool system though 😁

Can you run the Formula 1 GP benchmark ?

Yes, usually RAM is the limiting factor, but Harris CPUs don't overclock very well.
The fact that you have a chip that goes +9MHz is remarkable, but can be additional limiting factor.

Basically a 386SX-33 then. Impressive. Most impressive.

pshipkov wrote on 2023-07-13, 05:24:

Can you run the Formula 1 GP benchmark ?

Yes, usually RAM is the limiting factor, but Harris CPUs don't overclock very well.
The fact that you have a chip that goes +9MHz is remarkable, but can be additional limiting factor.

I believe Ekb actually tested different Harris CPUs and his findings were that 20 and 25Mhz parts are the same or pretty close as both go up to 30Mhz. His finding about memory are like my. You need fast memory to go beyond 25Mhz with 0-ws.

I plan on ordering 60Mhz oscillator and see if 30MHz is possible. Would be great to get some 45ns SIMMs.

I hope to play some more with this mobo over the weekend and also do F1GP benchmark...

yes, it is all about RAM when it comes to 286 overlocking at 0-ws past the 20mhz.
interestingly enough 45ns modules did not do better than well curated 60ns ones.

I tried with some 45ns DIP chips and didn't go past 20MHz with 0-ws. I wonder if there is a difference in operation between SIMM and DIP banks or those 45ns are "fake". Otherwise I had to try a few 60ns SIMMs to get a pair that are stable past 27Mhz.

Updated the 2nd post with 60MHz oscillator 😉

Good 60ns 1Mb simms will do for 30MHz 0WS.
You have to curate a lot.
Related notes here about brands that worked, also video card + vram memory is a factor.

Added Wolf3D to the 2nd post (@30MHz).

I guess I need to get my SIMM box out and see what's in there... will need more free time to actually do any tests.

Very nice 286 👌 I just got my hands on the same board! Which Bios version are you using? I´m asking because I have some troubles using smartdrv (crashes), windows 3.1 install (standard mode fault outside of ms-dos extender) and Wolf3d (no weapon shown during play and crashes after trying to shoot)? I´ve tried changing the simm memory, disabling various bios settings and a different graphics card! My bios version is DH1X-6069-113090-KF! I´m using 4mb of SIEMENS HYB511000BJ-60 SIMM memory modules, ET4000AX 9201, ES1869F and some unknown i/o card which worked in my previous 286! When I get it to function properly I will add my non overclocked stats for comparison 😃

I can check my BIOS version. Although I doubt it's a BIOS problem.