FSB Overclocking, Can you help?

[Acroam]

I am looking to put a better heatsink and/or fan on my northbridge chipset. I have 2 questions, a). Has anyone reviewed or had a Thermaltake Crystal Orb cooler installed on the northbridge, and how did it work? b). If used in conjunction with a Thermaltake Ramsink, will those 2 items allow me to up my fsb (frequency) of my motherboard?. I can upgrade the frequency to 150 and its stable, my mother board goes up from 150 to 155, and then at 166/33. Thats why i was wondering if those 2 cooling methods would help me reach the 166 without locking up before it can start. Thanks guys, you are the pros!

[Brad]

ram sinks very rarely show much of an improvement at all, I wouldn't bother with them.

before you go out and buy a hsf unit for the northbridge, just put a 40mm or 50mm fan on the northbridge heatsink, and see what happens to your fsb

[airspirit]

Your RAM and your PCI is your bottleneck.

Here is what you have to do. At 133FSB you have a 4X divider on your FSB to get your PCI bus speed. As you raise your FSB, your PCI bus goes up as well. PCI interface doesn't like this one bit and you start crashing. As you raise your FSB over about 155, you need to set your divider to 5X.

Also, your RAM is probably a holdup. If you are running a 333 or 400 board (most stable at high FSB) you need the corresponding faster RAM to raise the speed higher. Generic PC2100 RAM isn't going to give you 200Mhz FSB. Even Crucial and Mushkin PC2100 normally have problems getting over 166 FSB. You really need PC2700 RAM to get to that speed and higher.

Sorry I don't have much more I can say. If you can't raise your FSB any higher, supercool your processor and hack the multiplier through the roof.

Speaking of multiplier, sometimes you need to drop it in order to raise the FSB higher. Give that a shot. Also, raise your VCore as high as is safe, and bump up the VRam by .1. It could help.

[Balerion]

If your motherboard has a 1/5 divider like you say, then you might try upping your ram voltage to 2.6, 2.7, or maybe 2.8, and see how high you can go each time. If this works, I would definitely get some thermaltake heatspreaders. They will help prolong the life of your ram, since you'll be running it alot hotter.
When I was first getting my Epox up, I noticed that once I got to 160 and 165 my ram was getting REALLY hot to the touch, so I went out and bought a 10 buck set of ramsinks and heatspreaders, and now its just fine. Higher RAM voltages should allow you to take it up so you can get the PCI divider ot kick in.
If you still cant, try and remove some PCI devices, move up the FSB, then once you make sure the divider has set in, put the devices back in.

[Heavy_Equipment]

You don't say what board you are using.

Most KT266a boards had active cooling on the northbridge, while the KT333 boards that I have seen, (including the Epox 8K3A+...which, from all reports, is a killer OC'er) only have a passive cooler. (no fan)
That's proof enough for me that a KT333 board doesn't need any extra cooling there.

My Iwill XP333, with the Majik 1 rev. C chip, locks up in 30 seconds if I unplug the NB fan, at 133 MHz.
It runs fine with the stock cooler all the way to 201 MHz, where I visited for awhile, and at 174 MHz (memory timing brought me back) it ran flawlessly for the last 6 months.

I guess what I am saying, is if you have a 333 board, I'd be looking for blame elsewhere, as the stock cooling on that chip will be good for AT LEAST 166 MHz.

[jtroutma]

I agree with airspirt. It sounds like your PCI bus is holding you up.

Try removing all your non-essental PCI devices from your bus and see how high you can go. Another thing to keep in mind is that your HDDs are on your PCI bus and if they cant handle the higher BUS speeds, then they will probably be the problem by corrupting data.

The 5x divider on the MB (if you have one) would then be the solution. Otherwise, your pretty much screwed, sorry.