Disappointing BH7 OC results-need help

Hi everyone.

I've had a BH7 for a few days now. I bought it in the hopes of pushing my Pentium 4B 2.26 higher than my Asus P4S533 board. The Asus has the Sis 645DX chipset and does not offer a PCI lock or dividers of any sort. I was able to run 159mhz fsb with good stability with this board despite the fact that the PCI bus was at 39 or 40mhz.

With my BH7 I am now at a whopping fsb of 162 mhz; thats an increase of 3 for the math impaired. I have also gained 51 mhz cpu speed for my hundred bucks. With the fsb set at 163 and the voltage upped by 30% (the maximum) the system will POST but Windows will usually fail to load or lock-up shortly after loading. This fact alone is telling me that I have reached the limit of my CPU. If only I had known this before shelling out the cash for a "faster" motherboard!

Here are some more of my system specs. I have an Antec tower case with 3 intake and two exhaust fans. A 400w Antec Smart Power power supply. The cpu is being cooled by a Swiftech MCX462U heatsink with a Vantec Tornado fan pushing 84 cfm.(!) I just bought the fan today in the hopes that it would allow me to go further but it hasn't...its just loud! 55.2dB. I think this is about as good as any air cooling is going to get. For memory I have one stick (512 mb) of Geil DDR 466 Platinum memory. I'm running the 3:4 divider in the bios effectively running the ram at 432 mhz ddr (I think), so it doesn't look like memory is the limiting factor.

In conclusion, as I sit here writing this I'm at 162 mhz fsb, the vcore voltage is up 15%, AGP is at 1.6v, I'm playing some mp3s and the system is rock solid. Hardware doctor says that the cpu temperature is about 42-44C. This seems very high to me. I usually saw these temps under LOAD with my Asus board with lesser cooling and similar voltage. I too am experiencing the temperature problems that a lot of other BH7 users have seen. It jumps around sometimes 10 degrees celcius in either direction. Under load I see anywhere from 55-60 degrees. I think this artificially high too.

Does anybody have any comments, suggestions, questions, tips, tweaks...anything to get me more speed?!!

Thank you,
-Frustrated Abit user

First thing I would try is going 1:1 with your mem and see if your cpu is the limiting factor as I can't run 3:4 but 4:5 works fine. As far as your temps go, +30% could be the reason your temps seem a little high. I have a bh7 running a 2.4 @ 3.43 with no trouble, just took me some time to tweak and test, but I'm happy with my bh7

Nomjr, thanks for the reply. I'll give that a try tonight. With the P4S533 when the memory was clocked too high I got a blue screen in Windows. Now I just get a complete lockup...no bluescreen. Often times I also get some noise out of the soundcard when the system locks.

*UPDATE*
Last night I removed the OE northbridge heatsink, cleaned this pink gooey stuff off of the bottom, lapped the base (needed it), added a small fan to the top of the hs, and finally put everything back together with Arctic Silver 3. I have never done this with a "bare" northbridge before. All the ones that I have worked on have a heatspreader on them. When I booted the machine with everything put back together the system did not post and a few seconds later I got an alarm type sound out of the PC speaker. It scared the crap out of me. On the northbridge there are several transistors around the core and I thought I had slopped some of the AS3 on them shorting out the mainboard. I cleaned some of it off and rebooted. The system posted and loaded Windows but locked up shortly after.

So, my next best guess was that the heatsink itself was touching some of the transistors. There was a square piece of foam on the underside of the heatsink that I thought was there to prevent this from happening. I had reinstalled this piece but I guess it didn't work.

Next I made my own insulator out of some foam I had laying around. I cut a square out the center and laid this over the northbridge then stuck the hs on top. The machine booted fine but was still unstable. I had to lower the fsb to 159 to get any sort of stability in Windows...or so I thought.

I ran the Sandra burn in wizard (cpu arithmetic bench and multimedia bench) for 45 loops and everything was fine. I left the computer on (idle) all last night and it was still alive this morning. Just as I was about to leave the house this morning the damn thing locked again. I just shut it off in frustration and left.

So what in the world is going on here?! I thought I had improved the thermal dissapation of the northbridge but I had to lower the front side bus to get a stable machine!? Is it possible that the northbridge is why I can't get over 162fsb? Or did I screw something up?

bh7's can crank... a 220 fsb is common. I suspect you've reached the cpu limit if you ran a loop at 1-1 ratio..I know its depressing, sold my cherry 1.6a that ran to 2.6 no prob, got a brand new 1.8a c1 week 45. It wont run faster than 2.7...... felt like banging my head against the wall, but those are breaks...

Whats frustrating as hell is one day its stable at 162 and the next day I have to go down to 161...160...and now 159. When I first got the board I ran the Sandra burn-in wizard for 18 hours straight with no problems.

I think I'm gonna buy a 2.4g P4. People seem to be having better results with that chip. By the way...what is better for overclocking: retail chips or OEM? I would think that the retail versions have stricter quality controls...or is the additional cost just for the pretty box?

Yeah, you may just be at your limit on that cpu. Have you tried lowering your voltage at all on your cpu? On my BH7 with my 2.4, after like a week of running higher volts through it, I'm now back down to stock voltage and running 191fsb with my mem 1:1.

Also, what voltage are you running your mem at? I did the same thing on the NB, lapped/fan/foam/as3. Before I could barely hold my finger on it and now with the fan on it, it just stays warm, but not hot. Good Luck!

Nomjr,

Haven't tried lowering the voltage...I just keep going higher. Would that really help?

Memory is at ~2.8 volts which shows up as 2.7 in mb monitor. The ram is have is rated at ddr466 and I was able to run it at around 475 at 2.9v in my Asus board. Right now with the 3:4 divider and 159 fsb the ram is only at DDR424. According to Geil the chips are rated up to 3 volts...should I go that hight? BTW, I have always allowed SPD to determine memory timings.

I'll try lowering the memory speed and decreasing the voltage to the cpu and then try raising the fsb some more.

It just seems so weird that once I mess with the northbridge hs I have to lower the bus speed. Why is this?

For what it's worth, I have a lowly P4 1.6a that I just installed in my new BH7. I had to apply more voltage to the cpu to get it to run at the same speed as in my MSI 645 ultra. Good news is that I can run the chip faster 2.5 Ghz+ using the higher voltages available with this board!!!

You may need to try more voltage to the cpu to get stable...

I did it!

Great news...my machine is now running at 177x17=3009 mhz! The memory was the problem after all. I guess I misunderstood what the hw strap was doing in the bios. I had it at "Low" so I could take advantage of the 3:4 dram divider. Even though the system would POST at something like 200 for the ram it was not liking it. I set the hw strap to "by cpu" and the dram divider is 4:5. I can go higher than 3,009 mhz but I have to lower the divider to 1:1 and the bandwidth sucks at that speed. At 4:5 I get around 3300 mb/s of bandwidth. I'm running this configuration with the dram at 2.9v and the cpu is at +%25 which motherboard monitor reports as 1.82v.

I put my Thermaltake smart fan back on last night because the tornado was just too loud for everyday use. Well, the "little" Thermaltake fan cannot keep up with the cpu...its just too hot, even with the Swifty on it. So I put the Tornado back on today but like I said, its too loud for everyday use. Watercooling here I come!!!

Nice to hear that. I thought that might be it as I mentioned it earlier to give that a shot. I had the same trouble on one of my boards here and just changed it like you have it now and no problem. Glad you got it working