Imposibilitty of changing the FSB - AMD Sempron 2400+

[sergiu.ciocan93]

Hello guys,



I have the following problem with a project that I have out of an old system.

My cpu, even if it's a Sempron 2400+, it is shown as Athlon XP 1500+ because the FSB cannot be changed.

When I change it from the motherboard to 100 MHz it works just fine and is shown as Athlon XP 1000, everything works fine also when I set it to 133 MHz (-> Athlon XP 1500+), but doesn't work with 166 MHz even if the motherboard says it is supported.

Also, it cannot be changed in the BIOS (I have the latest version) to 166, only to 100 & 133 MHz.



PC Specs:

Motherboard: Asus A7S8X-MX socket A 462

CPU: AMD Sempron 2400+

RAM: 2 x 1 GB DDR 333 MHz

Video card: Asus A9250 128 MB

OS: Windows XP Pro SP3 32 bit

PSU: Delta Mini 80+ 300W

Bios: 1007

 

[mdd1963]

https://www.asus.com/supportonly/A7S8XMX/HelpDesk_CPU/

You have the latest BIOS per Asus....

Are there no multiplier settings, or were they locked?

Page 1-18 of your manual references FSB jumpers...are they set for 166MHz operation?
http://dlcdnet.asus.com/pub/ASUS/mb/socka/sis741GX/e1766_a7s8x-mx.pdf?_ga=2.160226238.221082596.1524770801-682735164.1521142878

 

[sergiu.ciocan93]

https://www.asus.com/supportonly/A7S8XMX/HelpDesk_CPU/

You have the latest BIOS per Asus....

Are there no multiplier settings, or were they locked?

Page 1-18 of your manual references FSB jumpers...are they set for 166MHz operation?
http://dlcdnet.asus.com/pub/ASUS/mb/socka/sis741GX/e1766_a7s8x-mx.pdf?_ga=2.160226238.221082596.1524770801-682735164.1521142878

No multiplier settings.
FSB jumpers are set on 166, but it is seen as 100 (->athlon xp 1000). So my best solution was to set those jumpers to 133 so I could get at least athlon xp 1500+

 

[mdd1963]

are we sure the RAM is PC2700(333 MHz)? (maybe it is selecting lower clocks if RAM can't keep up...? UNlkess there are options to run RAM asynchronously at lower clock speeds, not uncommon in that era)

GOod luck

 

[mdd1963]

You might also try dropping to one stick of RAM in required first slot, checking for change of behaviour as far as successfully operating at 166 MHz FSB, etc...; might expose if maybe one RAM stick is preventing it...

 

[sergiu.ciocan93]

are we sure the RAM is PC2700(333 MHz)? (maybe it is selecting lower clocks if RAM can't keep up...? UNlkess there are options to run RAM asynchronously at lower clock speeds, not uncommon in that era)

GOod luck

Hi,
I'm sure is 333. I wanted to buy the ram for 400 mhz, but I knew the motherboard will not support that, so I went with 333 instead.

 

[sergiu.ciocan93]

You might also try dropping to one stick of RAM in required first slot, checking for change of behaviour as far as successfully operating at 166 MHz FSB, etc...; might expose if maybe one RAM stick is preventing it...

Done that already. Same result.

 

[mdd1963]

remove BIOS battery, drain caps for 20 minutes, reinsert?