Overclocking 2.4c

I can only do 251mhz on fsb, at this setting its prime95 stable and no problems at all. However if I up it to 252mhz I get BIG PROBLEMS. Sometimes I even cant load up windows.

At 251mhz I run the cpu at 1.525v without problems but at 252mhz even with 1.8v its still bloody unstable.

Tempratures are fine, never above 40 degrees (celsius)
PSU voltages are fine, Ive even tried to push the psu too see if it would fail on even 251mhz without result

Memory runs fine up to 215mhz ddr. Currently at 251mhz fsb I run them on 200mhz.

What can be wrong?

my system spec is.

Asus p4c800
Intel NW 2,4c
1x 512mb corsair xms pc2700(does 220mhz) 2x Twinmos CH-5 512mb(does 215mhz)
350w chieftec psu
radeon9700(just upgraded it from 8500 so there is no problems in that area)

EDIT:
Forgot to say that all my memory modules run single channel cause I cant get them to work in dual channel

Make sure you have the PCI bus speed locked to default. If you already have done this, then it's probably a RAM conflict. Almost everytime I've seen a brick wall like this, it's RAM related.

pci is default

damn I hate this if its my ram, such a waste to sell my memory for almost free and buy new ones for full price

siDDis said:

1x 512mb corsair xms pc2700(does 220mhz) 2x Twinmos CH-5 512mb(does 215mhz)

EDIT:
Forgot to say that all my memory modules run single channel cause I cant get them to work in dual channel

Click to expand...

Ok, I was in a hurry on my first post and didn't look at your RAM configuration. Lose the 1X512 Corsair. Try using just the 2X512 Twinmos in dual channel and see what happens. You really need either 2 or 4 perfectly matched sticks of RAM for best results. You'll nearly double bandwidth using dual channel which will make up for the 512 MB less total memory. Unlike AMD, it's far better to run Intel systems in dual channel mode.

this sucks, removing the corsair module didnt help

however removing the twimos modules and using the single corsair pushed my cpu right up to its limit at 1.7v 290mhz fsb

Now I need 4 new memory modules to replace those I already have

I rather have 4x512mb than 2x512mb in dual channel

try running at 3:2.

if it's still unstable above 252 fsb, it's probably the processor that's limiting your o/c

my 2.4c can't get over 254 fsb without being unstable as well

He just said he reached the CPUs limit @ 290fsb, so this is strange. Sounds like the NB isnt liking the two sticks?

Also, asus under read -- add 10c to those temps mate :/

~t0m

well even with one stick of those twinmos modules it start hitcing at 250mhz+ fsb

So for now I will stay with 1.5gb memory and 250mhz fsb until that day I can afford new memory