TR Forums

FSB OC
Hi Guys, been tweaking away at my system in sig for the past few days and looking around internets @ other CH4 owners overclock and have noticed some peeps are able to reach a base clock (FSB) of 300 - 400 Mhz, however whilst playing around yesterday I lowered HTT, DRAM and NB frequencies to lowset values possible, dropped CPU Multi to 11 and raised Base clock to 300 this left my CPU at stock 3.3Ghz, this resulted in a no post situation, cleared cmos and tried again with 275 (CPU is underclocked this time)and same thing occured, finally got it to post @ 260 but was unstable.

Am I missing somthing because this seems really low for this board when compared to what I have seen others achive, do I need to raise any voltages to achieve these high Base clock speeds, I am using the 1102 bios, any advice appreiciated, also would be nice if people could post there OC settings including voltages.

I don't know if this issue has been resolved since I last owned an ASUS board but sometimes ASUS boards don't really like multiple of 5's FSB. I had a C2D board that was unstable at 250 FSB but was rock hard stable at 252. (doesn't make sense to me but it worked for some reason)

I know you can get slightly better performance by running a higher FSB but in your sig you have a BE processor, why don't you just crank the multiplier up to OC or move the FSB slightly higher to 250 (assuming that works) or so and crank it up from there?

Also remember OC'ing a board varies. Just because someone gets a 350 FSB does not mean you will. I have been on both ends of this. There is nothing you can do about it.

You need to increase the PLL voltage. Stock is 2.6v, take it to 2.66v and see if that helps. I also set the HT voltage to 1.25v. I haven't spent the time to isolate it to solely the PLL voltage, but that is a big part of it.

Thanks for the reply folks,
@mmmmmdonuts21, my board doesnt seem to mind multiples of 5 on the FSB ive booted stable and succesfully @225 and 250, and yeah i can reach 4ghz with using just the CPU multi, i just want to see how far i can push the board itself this is my first experience with new hardware since I just upgraded from a socket 939 opteron 175 system, in know an high OC is never gauraunteed and people get different results from the same board but i'm sure its capable of going faster since ive browsed loads of forums posts and read all the reviews for the board on the various hardware sites and the vast majority can get really nice OC's on the FSB with this board was just hoping i aint got a poor clocker, that would make me sad !!!!!! lol

@Logan, cheers for that mate most lilkey this is the answer I have been looking for, will get to testing straight after work tonight, i had tried giving the HT a little more voltage but not the PLL, makes sense that it could be the issue, how far do you think is safe on the PLL 2.6- 2.7 range OK or higher??????,

Isuppose I could check the specs of the PLL iteself for more details. anyway im just rambling now cheers for the help guys.

regards

Dyno

@Logan, is there defo a PLL volatage adjustment on this board, i just took a look @ a screenie of the xtreme tweaker BIOS section and can't see it listed

http://www.xbitlabs.com/images/mainboards/asus_crosshair_formulaiv-gigabyte-ga890fxa_ud7/bios_tweaker.png

well i sussed it, turns out my hardware config will not work with the lowest memory divider, overclocking..... the board or memory hits a wall @ just over 300mhz HT REF with slight Voltage bumps on the CPU and CPU\NB, not been able to isolate which one due to me only being able to use the 2nd lowest mem divider which with 300 HT REF is clocked at 1600 which is not too shabby for kingston value RAM IMO, can't wait to get my 2x2gb pair of GSkill ripjaws @ the end of this month,

keeping my CPU\NB\HT- Link at stock mhz and mem @ 1600 HT REF @ 300Mhz with my PII unlocked to a Quad the system seems stable i have left it primeing whilst at work today so hopefully will still be primeing away happily when I return and I can work on how far I can push the chip now that I know the board and memory limits.

thanks for the advice anyway folks

just to update, seems i cant get stable at anymore than 3.8ghz with this CPU as a quad ( i thinks its due to Temps tho ), also NB seems to top out at 2600mhz, so I have settled with 3.75 Ghz with 2500 NB and 1600Mhz RAM, system is 100% stable and speedy enough for my needs, didnt manage to get my New RAM yet, will have to wait till end of Jan now, then i can start my tweaking over again, and to try for higher clocks maybe a new CPU cooler too <<< any reccomendations on this my fellow Gerbils????