Help getting over 141fsb

Now that i've replaced my cpu duct, i'm trying to overclock higher. THe system runns stable at 141fsb, but any higher than that, 3dmark won't go through. My cpu is not unlocked, i think this may be the only hope for me as my mobo doesn't support pci divisors above 4. Any suggestions?

A lot of factors can influence oc-ability of the system- you may have an expansion card that just refuses to run out of spec.

One thing thats easy to test is memory though: are you running aggressive settings? Back them off to the lowest performance possible on your mobo and then try again.
If it works then memory is the problem (or part of it anyway.)

Your video card is oc'd too right? Setting it back to default first may also help.

If neither of those do any good, try removing pci cards one at a time to find which is/are holding you back.

NOTE: unlocking the cpu may not help- if the chip is "weak" it may be as high as it will go. But if the mobo is the problem, it may be that the ONLY way to oc is with a higher multiplier.

Hopefully something in there will make sense and help out a bit!
Good luck.

Yes, I agree it's probably the memory. I use to be able to only get 140 with my crucial 2100, but after lowering the settings for the memory, I was able to get it up to 148 stable.

But if you really plan to get it higher, unlocking it is probably the best way to go. I'm not as successful as the other guys here. But I was able to get it a lot higher after I unlocked my 1600+. It also seems more stable.

north bridge

adamtekh has it right if the mobo doesn't want you to go higher: does the northbridge have a fan on it? If not then pushing high fsb through it will overheat that puppy and .....CRASH!

I used to pull my northbridge sinks off and replace the stock thermal goo with AS2, and then put a fan on if it didn't come with one.

BTW- I am not convinced it IS your ram: any company can ship a bad stick, but I use ONLY cheap generic pc2100, and I can hit at least 166 with all but a few sticks. I do try to get sticks with Micron chips, but the sticks are made by a few different companies..

If the northbridge is the chip by my processor, then yes, the nice guys at abit put a fan on it, but its probabally on there with a thermal pad, i will put a better thermal interface material on tomorrow and let you know how it goes. I will also try relaxing my memory setting, i have it set to cas 2 - 2 - 2, the video card is overclocked. Also, i'm going to check my mounting or my hs tomorrow. Where would the stepping codes be on a palamino 1800?

unlock it! free ur cpu!

I have the AK35GTR and have been using micron pc2100 and samsung 2700 mixed and individually. I heard ur not supposed to be able to mix that stuff but I didnt realize until I was looking thru sandra 2002 and found the sticks listed next to each other. whoops! Anyways, like u I was unable to stay at 141 or even 140 fsb with a locked cpu. I only had an agp vid card and a modem card in the box so it wasnt pci probs. When I tried the Samsung ddr it was the same result.
I recently braved the task of unlocking the cpu with partial results.
I can get all settings except 12.5x. Not too bad. So anyways I am still trying to figure out the best possible performance settings because I can go as high as 155 fsb with either ram or mixed! with the xp 1800 underclocked to 10.5x . I havent had much success higher because I have to drop the multiplyer down more and that kinda sux. pretty soon ur at 1400 xp and 160 fsb? I did notice in one game that with the high fsb the game had stutters. hmmmm.... Anyways it u want that box to go higher u have to do the dirty......

I used super glue to fill the gaps ...tried the pencil and it failed.....prob due to cpu surface......then i went out and spent 10 bucks at car parts store and got a defogger repair kit and used that.....

good luck....I am currently running at 12x 139 fsb......1.67 ghz....

How old is your CPU? I got a new XP1800 about 2 weeks ago and i am stuck at 145 FSB and even then PRIME 95 doesn't like me and bombs out all the time. I have seen loads of similar threads about these chips not going past about 140-145 FSB i wonder if it is a dodgey batch?
details form my chip can be found here

It's still a respectable overclock +138 MHz takes me into XP2000 territory but I have seen better from these chips with similar cooling.

I am going to play with memory settings on my next day off see if that helps

Fixed a couple of things.

Some fans i bought came in the mail today. They were more powerful than the old ones. The fan in the power supply is the same as the old ones, but i didn't feel like taking the time to take the powersupply apart right now. I also applied silver paste to the northbridge ( the thermal grease job was horrible from the factory). I rearranged my pci cards so that my vid card ahs two open slots next to it. I removed the backplate from these two slots as I know my case pressure is very unbalanced on the positive side. I took the video card down a bit and right now I'm running at 143.38fsb X 11.5 vcc 1.8 (1.78 - 1.79 actual). The heatsink on the video card was glued on, does putting it in the freezer or using component cooler help? I'm going to buy a little fan for the geforce heatsink as its not active. I think the biggest thing holding me back is that the board does not support pci divisors above 4. I will do a runthrough with uninstalling everything and putting the pci back in one at a time to see what cards are holding me back. I'm awating reciept of a 120mm fan to be used as exhaust on top to help even out the case pressure. Unless anyone knows a mod to get divisors above 4. I almost forgot i got the number off my chip, here they are:

AX1800MT3C
AGNGA0202MPMW
Y7539750018
'S'?
I think that will be it for today.

instability

I've got an AK35GTR, and I can't get very high FSB. It goes to 148 alright, but freezes during the POST if I go higher. Also, some games generate errors if I'm at 144-148 FSB. The CPU can go as high as 1825 with a big multiplyer and can even run 3dmark at that speed. But a lower multiplyer doesn't let me get a single Mhz more of FSB.

I already put arctic silver on the north bridge heatsink. SHould I replace it entirely with something better? I've tested my NIC and USB card, switched video cards, and run 4 different sticks of PC2700 (OCZ rev1, Kingmax, Samsung, OCZ rev3) at weak timings or strong- makes no difference.

So the problem appears to be the motherboard. My 3.3v seems a tad low, 3.30-3.31v. maybe I should mod the VIO voltage for this board and the vmem while I'm at it. I'd get a new board, but am trying to hold out for kt400 and agp 8x.

Oh yeah, my HDD's are on their own channels on the RAID controller. Maybe I should put them in a master/slave config on the board's regular IDE channels and see what happens...

What are good voltages? Here are mine.

volts

Your 5v line is kinda low. Might want to find out if your PSU has potentiometers to adjust... What PSU do you have anyway?

Your DDR and vcore could also stand to be turned up a notch if you're aiming for more speed and more FSB.

That 5v rail is WAY low: the lowest I have seen any of mine go without crashing is 4.78v.

There are a few things you can do though: check voltage at a molex to make sure the reading is close.

There are a few threads dealing with psu issues- check the ol' search button.

I use Hoot's 5v Mod on a few of my boards, and another one needs it.

I would work on voltage before anything else right now.

i'm stuck at 141 too (cpuburn kills me no matter what i try in BIOS)... something i noticed on your readout: you're running 2x agp (3.5v) not 4x (1.5v). can the vid card not handle it? or did you forget to set it or something? anyway your vsb is lower than mine by .21, i dont know what that means, i just know that i have the same mobo and prog.

I was running PRIME95 and watching the +5V line and I think I found my problem. As soon as the CPU hits 100% usage the +5V drops to 4.7V and the core V drops to 1.79V.

I must say that this really p***es me off because I only just bought a new enermax PSU. It's a 450W silent series not just a cheapy either it cost me £60. I new I should have bought an Antec.

smudged in your case i dont think its the power supply that is causing the voltage problem, my 350watt enermax can hold its own. check out this thread for more info on the real problem. you might not want to perform the mod but if you can get some electricly conductive grease stuff (not sure what its called but i believe they mention it in that thread, no artic silver will not work) and put it on your atx connector then you might see better voltages.

you should try to test your 5V line on one of the 4 pin molex (the power thing that you connect to your hard drives/cd roms) with a voltmeter as mentioned in that thread to see what is causing the low voltages.

Hoot's 5v Mod is the balls
I've done it on 2 rigs and will be doing a third one of these days.....

I don't see any increase in voltage on my 5v lines, but they are a lot more stable: I used to get some pretty severe fluctuations when pushing my workstation HARD, and it barely wavers now.

The same thing with the seti cruncher (OC'd and a cheapo psu): when up/downloading wus the 5v line would drop from 4.9 to 4.8, and now it runs at 4.91v and drops to 4.88 or so. Got an extra 20mhz on that one

My video card is pci . I tried hoots 5v mod last night, but the wire i was trying to attach was too thick and just pumping the heat away from the joint. Couldn't get any solder flow. Same with both the 15W and 30W irons. Going to try again tonight with some smaller wire. Would u reccomend solid or stranded wire for this? If i could get my onboard 5V up to 4.85 i'd be very happy.

I used about 20 gauge aluminum starnded wire (about the same width as cheapo headphones use) but i braided the wire b4 i wrapped it around the pin on the mosfet. I tried it with a lower gauge copper wire but i couldnt get the solder to take.

I read that every mosfet you connect adds about 0.1v to your 5V line, i went from 4.7 to 4.78 after connecting one. I may try to add more but for now im just going to pull all of the fans from the motherboard headers and use 3 to 4 pin molex (molexes? molexs? molli? whatever the plural is), that may bring up the voltage a bit.

The only fans i have plugged into the mobo are the cpu and northbridge fans. The rest are coming right off the line.