this should be easy, set clock ratio at 2x and the amd5x86 would run at 4x instead.

Look in the manual and set the jumpers:
http://www.motherboards.org/files/manuals/47/4am_9503.pdf

I'm running AMD 5x86-133 @ 160MHz on this board. It's one of the fastest - right now I'm waiting for 1MB cache to arrive from China... about three more weeks to go 😉

kixs wrote:

Look in the manual and set the jumpers:
http://www.motherboards.org/files/manuals/47/4am_9503.pdf

I'm running AMD 5x86-133 @ 160MHz on this board. It's one of the fastest - right now I'm waiting for 1MB cache to arrive from China... about three more weeks to go 😉

noshutdown wrote:

this should be easy, set clock ratio at 2x and the amd5x86 would run at 4x instead.

I have tried the motherboard settings but the only jumpers that seem to change anything are the jumpers for the bus speed. I will try again when I get home from work (with luck my ide to compact flash adaptor will arrive today as well)

I have tried the 2x setting but it did not appear to do anything, but as I said ill give it a try tonight and see how I go.
Thanks for your help guys, @kixs did you get the cache off ebay? or if not have you got a link?

kixs wrote:

Look in the manual and set the jumpers:
http://www.motherboards.org/files/manuals/47/4am_9503.pdf

I'm running AMD 5x86-133 @ 160MHz on this board. It's one of the fastest - right now I'm waiting for 1MB cache to arrive from China... about three more weeks to go 😉

What cache timings are you running it with now? I will be surprised if you are able to obtain stable operation with 1 MB cache and the fastest L2 cache settings.

I hope you have an SRAM tester. All the incidences I have seen thus far of 128kx8 DIP-32 SRAM modules from China have had a 10% failure rate. Singleing out the bad modules without an SRAM tester is a real pain.

jmannik, there is a jumper on the motherboard which sets the 2x/4x and 3x CLKMUL signal. You need to find this jumper and set it at 2x. It may or not be marked. I think the jumper sets float or GND to CLKMUL to determine 2x/3x.

feipoa wrote:

kixs wrote:

jmannik, there is a jumper on the motherboard which sets the 2x/4x and 3x CLKMUL signal. You need to find this jumper and set it at 2x. It may or not be marked. I think the jumper sets float or GND to CLKMUL to determine 2x/3x.

I will be home soon I will have a good look, gotta clean up first the GF is coming over for dinner.

Well no matter what I did last night it wouldnt set itself to 2x...
It would stay at 100mhz or jump up to 120mhz but would not go to 133mhz, The strange thing is that when it jumps to 120mhz it was still set to 33mhz bus speed...
I might send an email through to Gigabyte asking for a bios update if they still have it.

Make sure you are not setting the jumpers backwards. Some motherboards are unintuitive on which pin is 1,2 or 3

smeezekitty wrote:

Make sure you are not setting the jumpers backwards. Some motherboards are unintuitive on which pin is 1,2 or 3

Lol I spent several hours on this, my memory of doing this many a time back in the day serves me well.
Thankfully this board actually lists on it which pin is pin one (but I also tried the other way as well to see if it made any change)

It is possible that the BIOS is misrepresenting the CPU speed configuration. Use CHKCPU in DOS to determine the proper FSB and multiplier.

feipoa wrote:

It is possible that the BIOS is misrepresenting the CPU speed configuration. Use CHKCPU in DOS to determine the proper FSB and multiplier.

Thanks, i will do that tonight. I only just realised you are referring to a progam 🤣.

feipoa wrote:

kixs wrote:

Look in the manual and set the jumpers:
http://www.motherboards.org/files/manuals/47/4am_9503.pdf

I'm running AMD 5x86-133 @ 160MHz on this board. It's one of the fastest - right now I'm waiting for 1MB cache to arrive from China... about three more weeks to go 😉

What cache timings are you running it with now? I will be surprised if you are able to obtain stable operation with 1 MB cache and the fastest L2 cache settings.

I hope you have an SRAM tester. All the incidences I have seen thus far of 128kx8 DIP-32 SRAM modules from China have had a 10% failure rate. Singleing out the bad modules without an SRAM tester is a real pain.

At the moment I have 512KB cache and it runs with the fastest settings. I read your previous posts about failure rate and I hope that at least 8 of 10 work 😉

What kind of failure can be expected - not booting with cache enabled, boots but errors accure, works with slower timings? Well I don't have any tester... I guess trial by error will do 🤣

Are you are running the system with 512K single-banked (4 chips) or 512K double-banked (8 chips)? 512K double-banked is more tolerant of faster cache timings compared to single-banked 512K when your FSB is 40 MHz or higher.

There were two types of errors I noticed with the SRAM. My SRAM tester noted the error types as:
1) some of the pins are disconnected internally
2) some SRAM chips returned incorrect data

The first noted error was the most prevalent.

These errors will often show up with the DOS HIMEM test, however it is the errors which come and go which are the most difficult to troubleshoot in the motherboard. The SRAM tester identified these occasional errors immediately, whereas the motherboard did not.

I do not beleive that slowing down the memory timings will help with these SRAM chips.

Well guys, it seems that when it says 120mhz it really does actually mean 133 😜 thanks for the help guys. That CHKCPU program is really useful

A BIOS update may fix the problems you are having with the BIOS incorrectly identifying the CPU speed.

feipoa wrote:

A BIOS update may fix the problems you are having with the BIOS incorrectly identifying the CPU speed.

Finding a bios update is the issue 🤣.
My bios is dated JUN 22, 1995 Rev. B

feipoa wrote:

Are you are running the system with 512K single-banked (4 chips) or 512K double-banked (8 chips)? 512K double-banked is more to […]
Show full quote

Are you are running the system with 512K single-banked (4 chips) or 512K double-banked (8 chips)? 512K double-banked is more tolerant of faster cache timings compared to single-banked 512K when your FSB is 40 MHz or higher.

There were two types of errors I noticed with the SRAM. My SRAM tester noted the error types as:
1) some of the pins are disconnected internally
2) some SRAM chips returned incorrect data

The first noted error was the most prevalent.

These errors will often show up with the DOS HIMEM test, however it is the errors which come and go which are the most difficult to troubleshoot in the motherboard. The SRAM tester identified these occasional errors immediately, whereas the motherboard did not.

I do not beleive that slowing down the memory timings will help with these SRAM chips.

I run 512KB with 8 chips. Last week I got working 1024kb chips and at first tried only 4 of them to get 512KB cache. The system wasn't stable - in PCPBench the red shaded C letter was all the wrong colors. After installing all 8 chips to get 1MB cache, everything worked OK 😀

I'm in the process to get Cyrix 5x86 and I hope it will work with this board. Just searched the net for the newest BIOS and it seems the last one supports it (dated 11/07/95).

ftp://ftp.hs-merseburg.de/pub/hardware/mainbo … /softwareo.html

The actual files can be found here:
ftp://ftp.dyu.edu.tw/pub/Hardware/stuff/bios/ … igaByte/GA_AMS/