CPU Voltage Adjustment

[Ritchie]

Thanks to the BIOS Numbers pages in Wim's BIOS, I have identified two boards:

Amtron PM-8800A VX PCI OR ASeagate VX (AWARD BIOS)

and

PC Chips M571 (AMI BIOS)

Interestingly, the first board came up as manufacturer Tyan in the manufacturer's table.


I do not require a BIOS upgrade, but am looking for some information on how to adjust the CPU voltage (or if it is automatic) so that I can support a 166MMX and 233MMX in these boards respectively. Any links to documentation would be appreciated.

I am confident that the CPUs should be supported, and the bus and clock ratios are already printed on the board. I just need to know about the CPU voltage settings.

Thanks
Ritchie

[KachiWachi]

They are both the same.

2.8V VCore (3.135V~3.6V)
3.3V V I/O (2.7V~2.9V)

[Ritchie]

Hi KachiWachi

Thanks for your reply.

What I am unsure of though and trying to find out is:

Do I adjust the CPU voltage manually on these boards with jumpers or do these boards auto detect the CPU voltage?

Ritchie

[Denniss]

http://m571.com/m571/

[Ritchie]

Hi Denniss

Thanks for your reply and link. I have bookmarked it.


Just before I recieved your reply notification I taken a closer look at both boards. When I followed the link the jumpers section confirmed what I just found out and now I can confidently install a different CPU on this board.


There is some bad news though. The Tyan (?) board has jumpers to adjust the PCI Clock, JP11 and JP10 to adjust the Bus Speed and JP13 and JP12 to adjust the Clock Multiplier. There are also RP15 and JP14 that I cannot account for at present. But I cannot find any reference to CPU voltages. I don't think RP15 and JP14 are related to CPU voltages.

So before I swap CPUs on the Tyan board I am still trying to determine if CPU voltages are automatic on this board or if I need to make jumper settings and which ones.

Any further information on the Tyan board appreciated.

Ritchie

[Denniss]

I doubt it's a tyan board especiall if the manufacturer ID in your Bios-ID is t5 instead if T5. Looks like another Pcchips board with illegal Award Bios.

[Ritchie]

Here is the information I wrote down from the board:


Intel VX Chipset

07/02/1996S

06/21/96-i430VX-2A59Ht5BC-00

AWARD BIOS


Board has VRM jumpers and and a cache slot, 3 PCI, 4 ISA, 2-PATA, 4 72 RAM, 1 168 RAM and a heatsink near the CPU, on a green coloured board.

[KURIAKI]

PcChips M520
PcChips M525
Atima MBP55FG
Pine PT-7502
Unitech MB520WB
t5 code have a misspelled character. I think it should be F5 for Fugutech.
Jumpers:
http://www.elhvb.com/mboards/pcchips/58 ... s_HTML.zip

[KachiWachi]

Got a pic of the board? I have an Amptron PM-7900 (M520) here...

[Ritchie]

I will see if I can take a photo and upload it somewhere.

[Ritchie]

I have not had a chance to upload photos until now, but now please find them at the following link: (please note they will take some time to download - they are several hundred KB each).

http://home.connexus.net.au/~geissler_family/PCIBoard

There are three photos and I am hoping to get a conclusive ID on the board.

Thanks
Ritchie

[Denniss]

Looks like M520, VRM-socket is empty so no split-voltage for MMX available. It's a bit risky to power them with 3.3V instead of 2.8/3.3V but it might work for some time.

http://www.stud.fernuni-hagen.de/q3998142/pcchips/

[Ritchie]

Thanks Denniss

That is what I was hoping to find out. With no dual voltage I will now leave the existing Pentium 166MHz non-MMX in the board, which is almost the best that it will run. I'd rather not install a CPU that the board does not properly support.

Out of curiousity at this stage, any BIOS upgrades available for this board?

[Ritchie]

Don't worry - have just found the available BIOS images using the link that Denniss supplied - thanks Denniss

[Denniss]

Have you ever tried to overclock your current CPU ?
Either raise FSB to 75 MHz or multiplier to 3x, maybe voltage needs to be set to 3.52V