2GHz - 15x133 versus 12x166...

My second question today:

My athlon 2400 runs at 2.0GHz (15x133.3333).
My memory (rated at PC2700) currently runs at 166 (fsb+33).

So I figured, if I increased the FSB on the chip and reduced the multiplier,
I could get better performance without extra heat:
Change CPU to be 12x166.666 - still 2.0GHz
Change RAM to run at 166 (fsb + 0)

BUT - the PC won't boot at these settings?!? I have to turn the fsb down to
around 160 to get it to start, but then CPU runs at
only 1920MHz.

Any ideas why it won't switch on at the higher FSB settings?



I have a Soltek SL75-DRV5 + Athlon 2400+ T'bred (15x133):
AMD Athlon TM
AXDA2400DKV3C 9574772250426
AIXHB 0321TPAW c 1999 AMD

Hi
I think the 75DRV5 is the KT333 chipset
although it has a 1/5th divider at 166Mhz not all motherboard makers
made use of it.
pump it to 160 and see if cpuid or simliar tells you what the pci/agp speed
are.
Also what memory are you running PC2100 or 2700 ?

Smiffy

Gareth Tuckwell wrote:
My second question today:

My athlon 2400 runs at 2.0GHz (15x133.3333).
My memory (rated at PC2700) currently runs at 166 (fsb+33).

So I figured, if I increased the FSB on the chip and reduced the
multiplier, I could get better performance without extra heat:
Change CPU to be 12x166.666 - still 2.0GHz
Change RAM to run at 166 (fsb + 0)

BUT - the PC won't boot at these settings?!? I have to turn the fsb
down to around 160 to get it to start, but then CPU runs at
only 1920MHz.

Any ideas why it won't switch on at the higher FSB settings?

I have a Soltek SL75-DRV5 + Athlon 2400+ T'bred (15x133):

This is your problem. Like many KT333 chipset boards, this one doesn't
properly support 166MHz FSB CPUs since it can't use the 1/5 divider. So when
you set a FSB of 166MHz, you're running the PCI bus way out of spec. I've
never managed to get a definitive answer from anyone (Via, Soltek) about
whether it's a BIOS, board, or chipset issue, but in any case I've never
seen anyone get a 75DRV5 to work properly with a 166MHz FSB CPU.

AMD Athlon TM
AXDA2400DKV3C 9574772250426
AIXHB 0321TPAW c 1999 AMD

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