Annyoing reboot problem if I overclock 2400XP

Blacklotus

Junior Member
Aug 9, 2003
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I have an annoyning problem with my new ASUS A7V8x-x & the 2400XP when I overclocked... it happens that if I overclock the 2400XP I cannot perform soft/hardware reboots :? ...if I do, system will always lock up before POST...but, instead, if I power down/up the system, everything works perfectly (bios settings remain intact) ...I've flashed the mobo bios to 1006 version, but still the same....don't know why this could be happening :?

On the other side, if I use default bios settings for 2400XP ( 133x15.0 ) reboot problem completely disappears.... :?

also, when overclocked, system runs rock stable and temp doesn't go any further than 40-45C

Any ideas about what could be going on ?

Thank you :D

System:

ASUS A7V8x-x 768DDR-333 XP2400@2.15Mhz ( 166x13.0 )
Club3D 9700np
120GB WD
80GB Seagate
PSU 400W Super Flower
1 DVD & a CD-burner
Thermaltake 2000A case ( 7xfans )

 

Harvey

Administrator<br>Elite Member
Oct 9, 1999
35,052
30
86
You may have to bump up the core voltage. Do it slowly, in small increments, until it starts to behave

Don't forget to monitor your temps! A fried CPU only goes to 0 GHz.

Good luck. :)
 

bjc112

Lifer
Dec 23, 2000
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Yep you could use a 5% votlage increase probably...

Also a small Vdimm ( Ram ) bump to about 2.8v would help also...
 

Blacklotus

Junior Member
Aug 9, 2003
7
0
0
thanks for the reply... :D

just tried it, atm seems not to fix the problem ...

I've slowly bumped up the core voltage up to 1.85v (from default 1.65v) but keeps locking up before POST...

it's fast to test...for example, when I save BIOS settings system reboots, it hangs, then I manually shut down the power supply, power on again....and voila, it boots normally :?

you think I should go for higher core voltages?

... the only thing I havent tested yet is to bump up dram v.

I've just found here http://www.rage3d.com/tech/?page=asus that there seems to be some kind of incompatibilities between 9700np and a7v8x-x which could lead to fail to boot...but if that's the problem, why I am able to boot always correctly when not overclocking the xp ? weird...

thanks :D


just checked the vdimm ...can't find any place to change it...neither in the bios or on the board :/
 

bjc112

Lifer
Dec 23, 2000
11,460
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76
Originally posted by: Blacklotus
thanks for the reply... :D

just tried it, atm seems not to fix the problem ...

I've slowly bumped up the core voltage up to 1.85v (from default 1.65v) but keeps locking up before POST...

it's fast to test...for example, when I save BIOS settings system reboots, it hangs, then I manually shut down the power supply, power on again....and voila, it boots normally :?

you think I should go for higher core voltages?

... the only thing I havent tested yet is to bump up dram v.

I've just found here http://www.rage3d.com/tech/?page=asus that there seems to be some kind of incompatibilities between 9700np and a7v8x-x which could lead to fail to boot...but if that's the problem, why I am able to boot always correctly when not overclocking the xp ? weird...

thanks :D


thanks :D

No no, back that 1.85 down... Even with a extreme overclock 1.85 is the absolute highest i would go... The issue lies somewhere else...

Try the Vdimm also, but that's more less of a stabilty helper in a Windows enviroment...


By any chance, do you have a spare video card you could throw in?
 

bjc112

Lifer
Dec 23, 2000
11,460
0
76
BTW, what OS?

Also have you tried overclocking in 1-5mhz increments instead of all at once..??

Edit: What type of ram? You need at least PC2700 to run a stock 166.
 

Blacklotus

Junior Member
Aug 9, 2003
7
0
0
just checked the vdimm ...can't find any place to change it...neither in the bios or on the board :/

I dont have any spare agpx8 to try it...but, this afternoon, my 9700np bios got erased by accident and had to take a pci vga from a friend to boot the system and restore the 9700np. At that point, the problem was still there... I don't know if that could be proof enough because although video outpot went through the pci vga, ati9700np was still plugged in. I could ask my friend to lend me this board again tomorrow and try it by having only the pci board plugged in if you find worth it ...

...no I haven't checked from what overclocking point an on system starts locking on soft/hard resets...what me to find it ?

RAM is Kingston DDR333 cas 2.5

thanks :)
 

Harvey

Administrator<br>Elite Member
Oct 9, 1999
35,052
30
86
I hope your first attempts to overclock are by raising the multiplier. That keeps your RAM and all your peripherals at default speeds.

You didn't name the brand of RAM. Could there be issues between your RAM and this motherboard?
 

bjc112

Lifer
Dec 23, 2000
11,460
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Is it Kingston Valure ram?

If so, you may have to relax your timings considerably to get it to run even at stock speeds...

However, some have also had decent luck with value ram...

Anyhow, what are your timings ( guessing default ) ?

And try 12x150 or even 13x150 just for sake of being able to boot the machine...

 

Blacklotus

Junior Member
Aug 9, 2003
7
0
0
sorry, forgot to mention it...yes, it's Kingston Value RAM...for what you say it seems not to be as good as some argue.... ;(

Following your suggestions I've performed further tests...these are the results :

+ Vcore was all the time at 1.75v ( default is 1.65v )

R-Ok = Reboot ok. No soft/hard reboot problems
R-Fail = Reboot fails. Soft/hard reboot stops working, manual power up
S-Ok = System ok. It dit boot the OS, ran 3Dmark's CPU tests 1+2 flawlessly and temp did not go any further than 44C
S-Fail1= System fails. System freezes even at BIOS. CPU Temp <= 44C
S-Fail2= System fails. System doesn't freeze but enters in a loop in which BIOS detects boot problems, goes into safe mode, you save same settings, boot fails, BIOS detects boot problems, goes into safe mode,... etc

12.0 x 150 - R-Ok, S-Ok (1800Mhz)
13.0 x 150 - R-Ok, S-Ok (1950Mhz)
14.0 x 150 - R-Ok, S-Ok (2100Mhz)
15.0 x 150 - R-Ok, S-Ok (2250Mhz)
16.0 x 150 - R-Fail, S-Fail2 (2400Mhz)

11.0 x 166 - R-Ok, S-Ok (1826Mhz)
11.5 x 166 - R-Fail, S-Ok (1909Mhz)
12.0 x 166 - R-Fail, S-Ok (1992Mhz)
13.0 x 166 - R-Fail, S-Ok (2158Mhz)
13.5 x 166 - R-Fail, S-Ok (2241Mhz)
14.0 x 166 - R-Fail, S-Fail2 (2324Mhz)

15.0 x 133 - R-Ok, S-Ok (1995Mhz) (System default)
16.0 x 133 - R-Ok, S-Ok (2128Mhz)
17.0 x 133 - R-Ok, S-Ok (2261Mhz)
18.0 x 133 - R-Ok, S-Fail1 (2394Mhz)

Well, that's it ... seeing these results seems the most interesting fail-safe setting would be 15.0x150, which underclocks dram to 300DDR but let's you overclock the CPU up to 2250Mhz without annoyances... What do you think ? I'll be using the PC mainly for gaming...

Respect dram timmings...been playing a bit with it in R-Fail/S-Ok scenery. Think my BIOS doesn't let much room for changes here. Only setting It made sense to me to changes was CAS Latency from 2.5 to 3.0 which did not solve the reboot problem. The other settings, I don't know how they exactly works, but seems to me they're already set by default to the higher value possible.

Here is current config and possible values :

CAS Latency -> 2.5 ( Ranges from 2.0 - 3.5 )
RAS to CAS Delay -> 3T ( Can be 2T or 3T )
RAS Precharge delay -> 3T ( Can be 2T or 3T )
Active Precharge delay -> 7T ( Can be 7T or 6T )

Besides these settings I haven't found in my BIOS anything else that could help to tweak DRAM

Finally, regarding possible issues between mobo & RAM...I've checked Kingston's mobo compatibility list... my mobo does not come listed, but there is an ASUS A7V8x-x DDR333 that could do (mine is DDR400)...and it has no know problems. However, I'll keep an eye on it for if something comes up :)


Thank you :)

 

bjc112

Lifer
Dec 23, 2000
11,460
0
76
There you go, stick with the 15x150...

Now you can slowly bump that FSB up 1 or 2 @ a time...

Who know it might work at 15x155 or so...

Let us know...

Good Luck.
 

Blacklotus

Junior Member
Aug 9, 2003
7
0
0
There you go, stick with the 15x150... Now you can slowly bump that FSB up 1 or 2 @ a time... Who know it might work at 15x155 or so... Let us know...

well.. at last ;) finally I've been able to run this box error free at 14.0 x 160 + 1.75v Vcore (320ddr & 2240Mhz) not bad :) :)

think I leave this settings for now... I'm quite happy with them :)

Thank you again for your help :p

I probably would gave up without it ...or even ended burning up the cpu ;)

Thanks :)

 

bootoo

Senior member
Apr 13, 2002
671
0
0
I have the a7v8x-x. I contacted asus and there is no vdimm option. Hmm, how nice! Anyway, I also have an xp2400+. I started with a multiplier of 10x and tried increasing my fsb up - it would perform as you are describing at 140, at 142 wouldn't finish 3dmark.

I got a suggestion to jump to 166 at 10x multiplier and did; noticing the secondary (pci ) frequency number was automatically set to 33. Guess there's some sort of automatic divider setting? Anyway then I crept up on the multiplier and ended up at 13.5x166. Had to bump the vcore to 1.75 in increments to stabilize it. Note that this board goes up in 0.5 volts increments not 0.25. Anyway it's been rock solid there ever since and takes everything I throw at it. I was using kingston valueram at the time. A bright idea to buy crucial made me happy but not any luck with going much higher so I'm back at those values stable, temps usually 42 C under load with an sk-7. Hope this saves you some hunting around.