Athlon II X2 won't stable past 250fsb

Sleeve · 23 Jan 2011 at 14:21

Currently OC'd my Athlon II X2 250 to 3.75 ghz stable, with 250 fsb and 15x multi.

But for some reason it just won't stabilise past 250fsb, even if i drop the multi and up the Vcore.

Any suggestions?

Thejay · 23 Jan 2011 at 14:46

You made sure you adjust the memory speed?

Sleeve · 23 Jan 2011 at 16:02

Well, i've got my Memory voltage set to 1.65, which is the rated volt. but whenever i try to set the memory to 667 it crashes on bootup.

What am i doing wrong?

Im using http://www.overclockers.co.uk/showproduct.php?prodid=MY-183-OC

spleenharvester · 23 Jan 2011 at 16:08

Gonna stay tuned to this thread, my 5000+ is the same, I can't get past 245 FSB stable and no matter what i do it won't work.

Thejay · 23 Jan 2011 at 16:11

The other one to watch for is when you increase the FSB speed the HT link speed also increases so need to adjust the multiplyer for the link speed.

Cookeh · 23 Jan 2011 at 16:20

That could be the fsb wall for your motherboard.

What board is it?

Sleeve · 23 Jan 2011 at 16:22

Cookeh said:
That could be the fsb wall for your motherboard.

What board is it?

Asus M4A78LT-M 760G

Thejay said:
The other one to watch for is when you increase the FSB speed the HT link speed also increases so need to adjust the multiplyer for the link speed.

See i've got it set to auto, what should it be at?

Thejay · 23 Jan 2011 at 16:46

If you open CPU-Z it'll tell you the current HT link speed, also have you got cool n quite disabled?

Sleeve · 23 Jan 2011 at 16:48

Thejay said:
If you open CPU-Z it'll tell you the current HT link speed, also have you got cool n quite disabled?

Yeh, HT link is 2500. Is that correct?

Frozennova · 23 Jan 2011 at 16:52

Drop the HT Link and CPU-NB to 8x and try again, most chips struggle above 2.5ghz run them as close to stock to rule out all posible problems.

Sleeve · 23 Jan 2011 at 18:17

frozennova said:
Drop the HT Link and CPU-NB to 8x and try again, most chips struggle above 2.5ghz run them as close to stock to rule out all posible problems.

Drop the CPU-NB to 8x, but i don't have a HT Link multi, can just set in mhz eg 800, 900, 1000 etc.

No idea what setting this needs to be on.

Thejay · 23 Jan 2011 at 18:23

For the HT frequency speed you want to add the fsb speed to what you set it to so for example 1.8ghz + 250mhz fsb = 2050mhz

Sleeve · 23 Jan 2011 at 18:41

Thejay said:
For the HT frequency speed you want to add the fsb speed to what you set it to so for example 1.8ghz + 250mhz fsb = 2050mhz

Ok, currently its on auto. And im at 3.75ghz.

Sorry, but im confused as to what to change it to...

Uriel · 23 Jan 2011 at 19:27

Drop CPU-NB multiplier to 8x and HT link to 1600. Maybe consider taking both lower. That might buy some more headroom. CPU-NB multiplier is just like your CPU multiplier. The speed is HTT (or FSB in old money) times multiplier hence 10x250 gives 2500 MHz. Stock is 2000. While you're finding your CPU's highest frequency keep CPU-NB frequency at stock.

HT link frequency can never actually be faster than the CPU-NB speed. Just remember that when you overclock the bus, this raises the quoted HT link speed by the same percentage. So at 250 bus (+50%) a 2000mhz HT link means 2500mhz.

Once you have found a stable CPU core speed, then try raising CPU-NB speed. If you hit a wall try raising the CPU-NB voltage slightly. If an extra 50-100mv doesn't help you've probably found the CPU-NB limit. Once you've found the CPU-NB speed then try gradually raising HT link to match. HT link is the last priority as it gives the least performance benefit.

Sleeve · 23 Jan 2011 at 20:03

Thanks for the advice.

Starting to question whether i should push it anymore.

I've already got an extra 750mhz, so maybe i should stop being greedy

Frozennova · 23 Jan 2011 at 20:30

Providing you dont push the Vcore too extreme you will be fine, ive ran chips with Athlon II chips 24/7 for months on end with 1.5vcore, 1.55v is getting a little extreme and anything after that will start causing degrading of your chip etc

Sleeve · 23 Jan 2011 at 23:30

Well i followed your advice and had a little bit of a tinker. But i ended up shorting a fuse and plunging my entire house into darkness.

Think ill leave it alone now lol.

Thejay · 24 Jan 2011 at 00:28

What the hell did you do? My Athlon II X4 is running 270mhz fsb :confused:

Uriel · 24 Jan 2011 at 00:36

That doesn't sound healthy. Whose advice were you following when the house plunged into darkness?

Thejay · 24 Jan 2011 at 00:59

I'd love to know what happened as when you get OC'ing settings wrong it just doesn't post lol :eek: