Help! Trouble overclocking FSB

[ddistasio]

Let me start by apologizing if this has been addressed elsewhere, I've tried to do alot of reading up before posting....
I'm new to overclocking but just built a system with the following specs:

1.4 Ghz AMD Athlon Tbird 266 with Alpha 8045 heatsink/fan combo (arctic silver II)
Shuttle AK31 Rev 2 mobo
7200 rpm Maxtor 40 Gb ATA/100 hard drive
ATI Radeon 64DDR
2 x 256MB DIMMs for 512MB total Crucial 2100 DDR

I have been able to get a stable 1.6 Ghz overclock of the CPU (12x133) running at 1.85v.

However, I can't even seem to get my FSB up to 135 stable. It fails under prime95 miserably within seconds due to a rounding error. An increase above 137 causes a reset and is completely unstable.

In the bios, I have the ram set to the host speed which should run it at the FSB speed.

In many reviews of the Shuttle Ak31 Rev2, I've seem much higher FSB overclocks. I can't seem to reliably get above the standard 133.

I was wondering if anyone has any suggestions or ideas.

My CPU load temperature is 51-52C (I need to do some work on the case) but I don't believe this would be influencing the FSB issue.

I'm wondering if I need to do something else in the BIOS settings? It doesn't seem like I should need to up the RAM voltage for such tiny overclocks...

The only other device I have on the PCI bus is an older sound card...I'm going to pull it to see if it makes any difference but wanted to see if there were other suggestions.

Thanks in advance!

[RocknBull]

hello

i would try 11x140 = 1540 see if it boots that way

[ddistasio]

RockNBull-

Thanks for the advice! After some tweaking, I've been able to get this baby steady at 11.5x140 for 1.61 Ghz. I don't seem able to get it any higher with either the clock multiplier or FSB, but this configuration appears rock solid under Prime95 + 3DMark2001 simultaneous testing. My only complaint now is I can't get my Crucial 2100 ram stable with this config with a 1T, 4 interleave. Oh well...guess I'll just have to settle for running the ram with a smaller bandwidth.

[TranceBear]

Originally posted by ddistasio
RockNBull-

Thanks for the advice! After some tweaking, I've been able to get this baby steady at 11.5x140 for 1.61 Ghz. I don't seem able to get it any higher with either the clock multiplier or FSB, but this configuration appears rock solid under Prime95 + 3DMark2001 simultaneous testing. My only complaint now is I can't get my Crucial 2100 ram stable with this config with a 1T, 4 interleave. Oh well...guess I'll just have to settle for running the ram with a smaller bandwidth.

I feel your pain, my FSB is limited also. See sig.