Hitting an OC wall with E2140

[clickynext]

I'm using Asus P5K-E, E2140 (L2 step), Crucial Ballistix 2GB DDR800

For some reason I'm hitting a wall at 2.8ghz, 350mhz fsb, at the 8x multiplier. Voltage is 1.35 bios, 1.30 under load. The RAM is being set to the lowest divider (700~800mhz), and has been shown to run fine at 1050mhz.

If I try fsb 360mhz with 1.375v bios, 1.325 under load, it boots into windows, but BSODs on stress testing. Any higher than fsb 362mhz, and it doesn't POST.

At 1.40v bios, 1.35v under load, there is no difference; can't get higher than fsb 360mhz.

Could it be the north bridge limiting the OC, or some other factor? I tried NB at 1.40v, but there was no difference. I'm not even sure what the default voltage of the NB is.

Thanks

 

[SerpentRoyal]

Sounds like a limitation of the MB. I couldn't get an Abit IB9 (P965) to break 350-360MHz FSB range. Popped in IP35-E and 400MHz with 1.505Vcore (E4300). I'd update to the latest BIOS and run 1:1 memory divider with 5-5-5-15-2T timing. Bump NB and SB up one to three notches. Those Asus boards run hot.

 

[harpoon84]

Agreed with SerpentRoyal.

My P5B Deluxe isn't stable past 370FSB on my E4400. I think it is due to chipset using the 800FSB strap, which is more aggressive than the 1066FSB/1333FSB straps. This is why you see E6x00 chips hitting 500FSB+, it's all to do with the memory strap.

There is a way to mod the CPU to 'trick' the mobo into thinking it is a 1066FSB part and use that strap instead. It involves some conductive paint though... so if you're game on that kind of stuff, heres the link:

http://www.xtremesystems.org/f...ghlight=1066+strap+mod

 

[clickynext]

Originally posted by: harpoon84
Agreed with SerpentRoyal.

My P5B Deluxe isn't stable past 370FSB on my E4400. I think it is due to chipset using the 800FSB strap, which is more aggressive than the 1066FSB/1333FSB straps. This is why you see E6x00 chips hitting 500FSB+, it's all to do with the memory strap.

There is a way to mod the CPU to 'trick' the mobo into thinking it is a 1066FSB part and use that strap instead. It involves some conductive paint though... so if you're game on that kind of stuff...

Are you talking about the "FSB to NB strap"? There's an option to change it in the bios: [200], [266], [333]

 

[harpoon84]

So your mobo has the strap settings in the BIOS? Cool. Yeah, try setting that to 266, see if it helps.

 

[clickynext]

Originally posted by: harpoon84
So your mobo has the strap settings in the BIOS? Cool. Yeah, try setting that to 266, see if it helps.

Thanks, I'll try that...

 

[clickynext]

Hmm, interesting. Changing the FSB to NB strap setting did nothing. Still limited to 362 FSB max, won't POST any higher. I even tried upping the NB and SB voltages, and CPU voltage a little bit more.

 

[harpoon84]

Darn. Did you try the 333 option as well?

 

[aiya24]

bump more volts. mine stops at 375fsb even with 1.4v. i settled for 375fsb @ 1.38v, 1.40v set in bios.

i've seen other e2140 stop there so its not out of the ordinary and i doubt its a board limitation. so far i have only seen the wall on L2 steppings not on M0.

 

[SerpentRoyal]

L2 is good up to 425MHz FSB. Quite a few users with E2140 north of 3.0GHz. See E21x0 overclocking thread.

http://forums.anandtech.com/me...=2099932&enterthread=y