- Joined
- Sep 9, 2001
- Location
- Pocatello, ID
Ok, I could use some help on this one.
I've been having trouble getting a reasonable overclock on my
Duron 750. It's an AKCA stepping, so I should be getting
somewhere in the neighborhood of 1 gig out of it according to the
charts. Thus far I can't reliably get beyond 940. Now before you
start telling me to check my cooling. I'm just talking about
getting the thing to boot. Cooling shouldn't be a significant
issue in this case. In general, as I increase the CPU speed
either by increasing the multiplier of the fsb, the first failure
I get is a two tone video card failure. If I increase beyond that
I get a repeating long beep indicating a ram failure. But if I
increase a bit more I just get a black screen, no beeps at all.
The drives spin up and the mobo led lights up, but nothing appears
on the screen.
Now there are several odd things to throw in to the mix.
First, sometimes I can get the machine to boot at a certain speed,
run the machine stably for several hours, but as soon as I try to
reboot, it won't boot at all. By not booting at all, I mean I
don't even get to the POST, I either get a video card not found beep, or i just get a black screen. When this happens I can sometimes get past it by turning the machine off at the PSU. That is, in certain configurations if I do a standard reboot, it won't boot; if I do a reset, it won't boot; but if I shut the power off at the PSU, turn it back on, and then boot the computer, it boots fine. Sometimes even this procedure won't coax a reboot and I just have to clear the CMOS and start over.
Second, I can sometimes coax a higher speed from the cpu by
fiddling with the video card. The odd thing here is that the best
speed is often obtained by having the card only half seated. Also
it seems to be better if I end the fiddling by applying a slight
outward force on the card. Might I have a bad AGP socket? How would I verify this?
Third, as long as I don't push the bus over 140, the computer either runs stably or not at all. Below 140 if I can get it to boot, then it will run stably for days. So it's an all or nothing thing. Above 140 fsb it will sometimes boot but run a bit unstably. The KT266 chipset isn't known for it's fondness of high fsb, so this isn't too surprising. But it strikes me as odd that below 140 it's all or nothing. I would have expected instability to creep up gradually (as it does above 140).
Fourth, if I'm running stably at 900 or more and I mess with the motherboard (take off the heatsink for instance) it will stop booting until I reseat everything again. Once I even had to reseat the extra USB ports to get it to boot.
I've only got a 250watt PSU (brand is ENHANCE), but I get these same results even with all the drives and extra fans disconnected. Also my 5v rail *never* drops below 4.92, most of the time it sits at 4.95 on a full load. I've checked by running MBM on a 1 sec interval for several days of folding. In fact it's been running on full load for three days now and MBM shows a low voltage of 4.95. But it does sometimes dip to 4.92.
I've successfully run the CPU at 1006 for several hours. (This
required finding just the right combination and then several
attempts at juggling the Video Card just right.) At that point I decided to reboot just to check for consistency. It wouldn't
reboot when I tried and I didn't have the time to futz with it
right then. So the CPU seems capable of higher speeds.
I've tried using a different Video Card with similar results. I
didn't spend a lot of time, but just switching cards didn't make
things better. However, the card I switched with was an Asus
V7100 MX, very similar to my normal card.
I've got generic ddr. It's actually Micron sold as generic. I'm
guessing that it's not nearly as good as Crucial. I've reseated it
multiple times, just to make sure there wasn't a problem that way.
I've tried upping the vcore and ddr voltage to the max the mobo
allows without a mod (1.85 and 2.7 respectively) This helps some, but not a lot.
For the record my full load cpu temp is running about 116F (47C), but as I've said, I'm pretty sure this isn't a temp problem because it's not even getting to POST.
Well, that's all I can think of at the moment. Any ideas or
questions?
At this point I'm inclined to think that the motherboard is
faulty. But I'd like some opinions before I go the RMA route only
to be told that the mobo is fine and I need to pay shipping. In addition to the stuff in my sig, I've got a cdr, an ancient cdrom, a Linksys NIC, and 256meg of ddr.
nihili
I've been having trouble getting a reasonable overclock on my
Duron 750. It's an AKCA stepping, so I should be getting
somewhere in the neighborhood of 1 gig out of it according to the
charts. Thus far I can't reliably get beyond 940. Now before you
start telling me to check my cooling. I'm just talking about
getting the thing to boot. Cooling shouldn't be a significant
issue in this case. In general, as I increase the CPU speed
either by increasing the multiplier of the fsb, the first failure
I get is a two tone video card failure. If I increase beyond that
I get a repeating long beep indicating a ram failure. But if I
increase a bit more I just get a black screen, no beeps at all.
The drives spin up and the mobo led lights up, but nothing appears
on the screen.
Now there are several odd things to throw in to the mix.
First, sometimes I can get the machine to boot at a certain speed,
run the machine stably for several hours, but as soon as I try to
reboot, it won't boot at all. By not booting at all, I mean I
don't even get to the POST, I either get a video card not found beep, or i just get a black screen. When this happens I can sometimes get past it by turning the machine off at the PSU. That is, in certain configurations if I do a standard reboot, it won't boot; if I do a reset, it won't boot; but if I shut the power off at the PSU, turn it back on, and then boot the computer, it boots fine. Sometimes even this procedure won't coax a reboot and I just have to clear the CMOS and start over.
Second, I can sometimes coax a higher speed from the cpu by
fiddling with the video card. The odd thing here is that the best
speed is often obtained by having the card only half seated. Also
it seems to be better if I end the fiddling by applying a slight
outward force on the card. Might I have a bad AGP socket? How would I verify this?
Third, as long as I don't push the bus over 140, the computer either runs stably or not at all. Below 140 if I can get it to boot, then it will run stably for days. So it's an all or nothing thing. Above 140 fsb it will sometimes boot but run a bit unstably. The KT266 chipset isn't known for it's fondness of high fsb, so this isn't too surprising. But it strikes me as odd that below 140 it's all or nothing. I would have expected instability to creep up gradually (as it does above 140).
Fourth, if I'm running stably at 900 or more and I mess with the motherboard (take off the heatsink for instance) it will stop booting until I reseat everything again. Once I even had to reseat the extra USB ports to get it to boot.
I've only got a 250watt PSU (brand is ENHANCE), but I get these same results even with all the drives and extra fans disconnected. Also my 5v rail *never* drops below 4.92, most of the time it sits at 4.95 on a full load. I've checked by running MBM on a 1 sec interval for several days of folding. In fact it's been running on full load for three days now and MBM shows a low voltage of 4.95. But it does sometimes dip to 4.92.
I've successfully run the CPU at 1006 for several hours. (This
required finding just the right combination and then several
attempts at juggling the Video Card just right.) At that point I decided to reboot just to check for consistency. It wouldn't
reboot when I tried and I didn't have the time to futz with it
right then. So the CPU seems capable of higher speeds.
I've tried using a different Video Card with similar results. I
didn't spend a lot of time, but just switching cards didn't make
things better. However, the card I switched with was an Asus
V7100 MX, very similar to my normal card.
I've got generic ddr. It's actually Micron sold as generic. I'm
guessing that it's not nearly as good as Crucial. I've reseated it
multiple times, just to make sure there wasn't a problem that way.
I've tried upping the vcore and ddr voltage to the max the mobo
allows without a mod (1.85 and 2.7 respectively) This helps some, but not a lot.
For the record my full load cpu temp is running about 116F (47C), but as I've said, I'm pretty sure this isn't a temp problem because it's not even getting to POST.
Well, that's all I can think of at the moment. Any ideas or
questions?
At this point I'm inclined to think that the motherboard is
faulty. But I'd like some opinions before I go the RMA route only
to be told that the mobo is fine and I need to pay shipping. In addition to the stuff in my sig, I've got a cdr, an ancient cdrom, a Linksys NIC, and 256meg of ddr.
nihili