My C400 won't hit 500mhz

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nysimonsez

New Member
#1
Currently it's at 450 and very stable, with 2.0v at temperature reaching as high as 38C.

However, when I turn it up to 500 (83mhz fsb) system freezes in Win98 within 5 minutes. I've tried voltages from 2.0, 2.05, 2.1, 2.2, all with same result. My AGP is turn down to 2/3. And temperature never reached higher than 34C and it freezes. The weird thing is it boots into win98 fine. I can use it for about 5 mins and then freezes. Temp reading at that time is below 35C.

Can it still be a cooling problem when I can hit 450 at a higher temperature? I read in another post that HD might be a cause, how can I check that? Should I burn in the chip at 2.2v for a while even if the system crash just to let it get used to it?

Here's the current specs:

C400 @ 450
bh6 at 2.0v temp monitored between 29C to 38C
128 meg PC100 cas 2 ram
16 meg agp diamond monster fusion
SBLive value
Zoom 56k modem internal
cpu heatsink with dual fan
front and side case fans in Inwin 500a case
WD 10.2g caviar ata66 HD @ 5400 rpm

Any comments or suggestions you may have are wellcomed.

If I can't get it to 500 stable, I'm still quite satisfied at 450. Just wanted to give it a shot.
 
R

rockinwy

New Member
#2
I have the same cpu on the same motherboard, voltage doesnt seem to be a problem with most 400's the problem is heat, mine would crash as soon as the temp got over 100 degrees f, and thats really not very hot, 33-34 degrees c. I water cooled my heatsink and that stopped all the stability problems, I am currently trying out a peltier that I order from overclockers.com so far it works but case cooling is a problem because peltiers produce an extreme amount of heat while cooling the cpu. Try using cpuidle and see if that will let your system run longer without crashing, you should be able to browse the web and other non cpu intensive things but it will still crash playing games then it is definitely heat related.
 
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rockinwy

New Member
#3
by the way the only heatsink that will let your cpu run under 100degrees with special cooling is the alpha cooler, I would recomend that before a peltier unless you are going to try and supercool the chip, then you get into alot of expense, additional power supply, and lots of fans....
 
T

tkbrewer

New Member
#4
Well, it may not be your CPU. Running at 83mhz FSB, your PCI cards are running at a much higher PCI bus speed than they are supposed to. This could cause lockups and bunch of weird things, also could cause your harddrives to lock up.

Good cooling and nice ventilation are good, but 83mhz FSB can sometimes be hard on PCI and Hard drives.

------------------
"You know what I like about Imac's?
They have a Handle, so I can throw them farther"
 
S

Sterling_Aug

Guest
#5
My Celeron 400A is running rock steady at 500 MHz using a Matrox Millenium II 4 meg PCI card. My Diamond Viper 16 meg AGP would have problems booting.

I think my Quantum HD is what is holding me back from 600 MHz now. I have an Alpha heatsink and a peltier cooler along with 2 extra case fans over 170 cfm.

The temp. that nysimonsez is seeing is only his case (motherboard) temp and NOT the actual CPU temp. My C400 in the same motherboard while running 500 MHz @ 2.3 volts has a case temp of 30C with all of the extra cooling. The CPU temp is QUITE a bit higher than the case temp, probably in the area of 8-10°C higher.
 
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nysimonsez

New Member
#6
Is there a way to pinpoint the problem, if it's HD, video card, or heat?

Sterling_Aug- So you mean the temp sensor from the bh6 is somewhere on the mb, and not from slot 1? My dual fan heatsink is hooked up to the mb. And how do you know your HD is holding you back from 600?

I'm going to try running it "topless" this weekend and hopefully remove the heat issue and see if it hits 500.

Thanks for all your comments/suggestions so far, much appreciated.
 
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Sterling_Aug

Guest
#7
nysimonsez: I know it is my P.O.S. Quantum H.D. cause it boots into the BIOS, checks my RAM and drives, starts to load Win98 and hangs.

The sensor on the BH-6 is on the motherboard, not the thermal diode reading. The BX-6 has a Winbond chip on it that reads the CPU thermal diode, but the BH-6 does not.

Running with the case off will probably not help much, and you may even see the case temp go UP. Good air flow is critical.
 
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nysimonsez

New Member
#8
Thanks Sterling_Aug.

Actually mine at 500 starts up fine.. post, count ram, load win98. Then after a few mins in win98 it hangs. Sometimes I did notice it hangs when it access hd, so maybe that's a cause in addition to heat.

At 450, case temp hit 39C last night and still running smoooooth.....go figure.
 
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rockinwy

New Member
#9
well so far good advice from everyone, harddrives can cause problems but if its the harddrive most likely windows will crash before it boots, my seagate corrupts everything when I enable dma in windows so I leave it off, my banshee card is agp and works at 2/3 or 1/1 and my pci modem works perfectly also, but it depends on the card. if the computer just locks after a few minutes no matter what is running, most likely it is heat, for some reason alot of 400's will run hot at 450 but to run at 500 they have to be cool, theres no way around it. by the way I am measuring cpu temp with a radioshack digital thermometer with the sensor on the back of the cpu, so whatever temp I get on the back you know the cpu is a little warmer than the slug and probably inbetween what the slug and the actual core are. too bad the bh6 doesnt have cpu temp.
 
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rockinwy

New Member
#10
by the way your hardrive isnt holding you from 600 either that 100mhz busspeed and what is recomended in the first place, if it wont boot it is the cpu, I have only seen 1 400 make it to 600 on all of the bulletin boards I have seen, not very good odds. jI dont remember if I said before but my 400 running at 500 is at 2.0 volts
 

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