PLS explain this phenomenon!

[tres0n]

Long story short: I just can`t overclock my p4p800 in dual channel mode as high as in single channel mode! In dual it won`t go past 257 mhz fsb, in single (only one of ram modules used) it will do 273. WTF? After mem voltmod, it`s quite sweet on 247mhz fsb @ 1,6memdivider Ram@2-2-2-5/8, but still i would like to go higher and on more loose ram timings, as the fsb is really a bottleneck here. My specs are as follows:
CPU - P4 2.4C
RAM - 2x256mb KINGSTON PC3200 2.5CL
MB - yes, asus p4p800 non DL
Video - GigaByte R9800PRO, as it would matter
What else is cruicial?

Any suggestions on this?
Thanx!

 

[ukdan]

just a guess but perhaps one of your ram modules is faulty, try testing them.

 

[Orka]

nothing faulty, i think. the two memory modules are not matched pair, aren't they?
so you just hadn't much luck getting two unchecked together modules to work good together.

 

[tres0n]

Hey, folks! Actually, i bought them as pair, if i remember correctly. Anyways, i`ll double check them by testing separately. But i rather doubt the possibility, they`re so unmatched, that it won`t boot past 257FSB even on 1,33 RAM divider. Go figure. Still remains mistery for me.

 

[DJ Switch]

I will 3rd the opinion about the RAM being your problem. One of them must be a dud (to some degree). If all else fails run the 2 in single channel on their own respective channels (one on A, and one on B). Let us know.

 

[tres0n]

I will 3rd the opinion about the RAM being your problem. One of them must be a dud (to some degree). If all else fails run the 2 in single channel on their own respective channels (one on A, and one on B). Let us know.

Just tested them in single channel mode as you said - one on A, one on B slots. Works just fine up to 273 fsb. Damn, i`m starting to believe it`s a mobo issue. Crap! What do you guys say?

 

[Merc Zephyr]

tresOn:

Do your RAM modules have Winbond CH-5 chips? I encountered a similar situation around 255fsb 5:4 with my 3500EL's. I could only push the fsb higher in single channel mode. I think this is an issue with the P4P800 and CH-5. If anyone has any more info on this, it would be interesting to know.

 

[tres0n]

tresOn:

Do your RAM modules have Winbond CH-5 chips? I encountered a similar situation around 255fsb 5:4 with my 3500EL's. I could only push the fsb higher in single channel mode. I think this is an issue with the P4P800 and CH-5. If anyone has any more info on this, it would be interesting to know.

You`re damn right they are! Geez, i think we have figured it out! Anyways, the beer is over, still i have a few kg`s left with strawberries. (Gotta get rid of this ram).

 

[tres0n]

Swapped my ram today with friends kingston CL3 PC3200 (mT -5BC). Hehehe, does this ram rock! Now i`m up @ 270FSB no prob! Running the ram @ 432Mhz 2,5-2-3-5/8! My sandra scores jumped from 5400 to 5800. And in 3dmark1 i got 19300 instead of 18500. Not bad, not bad.
Conclusion: P4P800 & Winbond CH5 ram (in dual mode) = NO GO. So avoid this combination.

 

[Mr.Guvernment]

as i was always told having 2 sticks of ram can be a problem for overclocking as opposed to having 1 - i do not think dual channel would solve this.


It is just something with the way a system works 1 sticks can sometimes give better results then 2 sticks.


Did you try using higher setting on your ram such as 3-3-3-8 ? or something like that..


Also PC3200 is 200mhz x 2 DDR400 - what ratio are you running your ram @? as once you go to 201 FSB your memory is running out of spec.

 

[DJ Switch]

Appears to be 4:5.

 

[Merc Zephyr]

Mr. Guvernment, I believe you are absolutely correct. However, there seem to be common issues with overclocking the p4p800 in 5:4. This is not the first post I have read from someone hitting a wall with CH-5 based RAM at around 255fsb 5:4 on this mobo. My 3500EL goes to 220fsb 1:1 and 255fsb 5:4 was rock stable but 256fsb would crash my computer.

I should also note that running 5:4 with the CAS set to 3 is another issue that others including myself have had with the p4p800. The board may not post with this setting.

Not trying to be argumentative, just point out some issues specific to this mobo that some people have experienced. Cheers

as i was always told having 2 sticks of ram can be a problem for overclocking as opposed to having 1 - i do not think dual channel would solve this.


It is just something with the way a system works 1 sticks can sometimes give better results then 2 sticks.


Did you try using higher setting on your ram such as 3-3-3-8 ? or something like that..


Also PC3200 is 200mhz x 2 DDR400 - what ratio are you running your ram @? as once you go to 201 FSB your memory is running out of spec.

 

[Mr.Guvernment]

Sounds interesting -= i got a P4P800 and will have some pc3200 and am getting a 2.6C - so IF my chip clocks that high i can try to confirm this

 

[tres0n]

Yea, those issues Zephyr mentioned are a real pain in the ***, clocking with this moboard! Sometimes, i wish i wouldn`t have gone with asus.