Tiny but annoying problem with the Epox 8K7A+

[S0me1X]

Hi,

I am running an 8K7A+ and Athlon XP 1.743 Ghz. (10.5x166)

The problem is that when I overclock the FSB, the computer won't reboot properly. When windows restarts or when I reset the computer, the computer will not post. However, cold boots work perfectly and the system is otherwise stable. Does anyone know how I can fix this problem?

edit: I upgraded the power supply from Enermax 300W to Topower 370W and the problem persists. I found out that the board will reboot properly at around 148 fsb but at 166.

The 8k7a can run at 166mhz and still have pci/agp in spec because it switches to pci 1/5 divider at 166+ fsb,

 

[Boonesmi]

what powersupply are you using?

 

[S0me1X]

Enermax 300W

 

[InterWebGuy]

think you might have nailed it right there.

 

[Tanked]

300 watts should be adequate, although slightly on the low side. That's probably the problem.

Are your AGP and PCI clocks running out of spec? If they aren't, tell me how you did it

 

[Floydian]

i'd say p/s as well, 300watts is usually low unless its a higher quality p/s (but even then its still low)

 

[S0me1X]

Upgraded the power supply and it didn't help the reboot problem However, my 5v rails have gotten much better, so I guess it wasn't for nothing.

Any other ideas?

 

[Mem]

Any other ideas?

Tried bumping the ram voltage and cpu core voltage up a little?

 

[Boonesmi]

also you may want to download memtest86 (from memtest86.com)

its a great little utility to check your ram and memory subsystem.. lets you know if the ram is causing any errors

 

[LostHiWay]

The 8K7A+ doesn't have the 1/5 divider. The only EPoX boards with the 1/5 divider are the 8K3A series and 8K5A2 series (Both on the KT333 chipset). That's probably your problem. You could also try upgrading to the latest BIOS that may help you out.

 

[S0me1X]

Originally posted by: LostHiWay
The 8K7A+ doesn't have the 1/5 divider. The only EPoX boards with the 1/5 divider are the 8K3A series and 8K5A2 series (Both on the KT333 chipset). That's probably your problem. You could also try upgrading to the latest BIOS that may help you out.

Where did you get this information? Epox tech support tells me that the 8k7a and the 8kha (kt266) both supports 1/5 divider. Various reviews also say that the bios after 7/11/01 supports the 1/5 divider.

As for the CPU voltage, I tried upping it to 2.0v (which is borderline for air cooling, imho) but it didn't help it reboot properly.

 

[LostHiWay]

Originally posted by: S0me1X

Originally posted by: LostHiWay
The 8K7A+ doesn't have the 1/5 divider. The only EPoX boards with the 1/5 divider are the 8K3A series and 8K5A2 series (Both on the KT333 chipset). That's probably your problem. You could also try upgrading to the latest BIOS that may help you out.

Where did you get this information? Epox tech support tells me that the 8k7a and the 8kha (kt266) both supports 1/5 divider. Various reviews also say that the bios after 7/11/01 supports the 1/5 divider.

As for the CPU voltage, I tried upping it to 2.0v (which is borderline for air cooling, imho) but it didn't help it reboot properly.

Both boards were rumored to support the 1/5 divider but it was confirmed that EpoxTech over at AOAforums that neither of them do.

 

[S0me1X]

Do you have links to the thread(s) where Epox Tech says there is no 1/5 divider for those boards?

The few threads where Epox Tech posts seem to say that the 8k7a and 8kha supports the 1/5 divider:
http://www.aoaforums.com/forum/showthread.php?s=00eae36c0fd0ce04663488465559b040&threadid=1284&highlight=8k7a

Also, Epox Tech's posts are extremely vague - he never seemed to directly say "there is/is not a 1/5 divider on the 8k7a/8kha"


sample post from ET:

"The answer still remains !!! If it runs and is stable does it matter ????????" (as in does it matter whether the board is running at 1/5 or 1/4 divider)


"All of this divider talk is getting quite a bit irritating ! I think we should stop worrying and address the issue of if it works at 180MHz, 190MHz or 200MHz Host Clock, fine, if not tough. Period."

 

[blackhawk]

to answer the 1/5 divider question, if you have sisoft sandra 2002 pro, go to the mainboard information module and it will tell you your pci and agp speeds as you scroll down.

I too heard the 1/5 divider rumour but saw no mention of it in the bios and epox seemed to enjoy the rumour but refused to acknowledge or deny. It was good for business.

I'm very happy with my 8k7a at 145mz and my 8kha+ at 141mz, fast enough for me.

Another good source for info is here at amdmb's

Just go to the forums for the mb you want to learn about.

 

[syadnom]

an enermax 300Watt supply should be fine, on the low end but still fine. how much power do you think you neeD? AthlonXP 1.743Ghz, prob about 80-100Watts? 20 mobo, 35HD/35CDR&DVD=70? <10 RAM ~40 vid card. =210-230 or so, and you want 50+ Watts for buffer zone = 280, still very easily enough power. and enermax is not some crappy brand that you can't trust its 300 watts to be 300 watts.

8K7A+ ,does not handle 1/5 PCI divider, so your running your PCI and AGP @ 41.5, way out of spec, you should expect some issues. even at 37(for 148FSB) your close to the line for some PCI/AGP cards. 35-36 is usually pretty safe so thats where i would say your prob is, keep that FSB down to <145Mhz and up your multiplier to 12x. your memory bandwidth will be cut down a bit but your computer will be functional at least.

as for that 1/5 PCI divider, some people get early boards that supported it via a beta bios, but it is not present in the vast majority of boards, and the board is not stable with this beta bios.

 

[S0me1X]

Originally posted by: syadnom
an enermax 300Watt supply should be fine, on the low end but still fine. how much power do you think you neeD? AthlonXP 1.743Ghz, prob about 80-100Watts? 20 mobo, 35HD/35CDR&DVD=70? <10 RAM ~40 vid card. =210-230 or so, and you want 50+ Watts for buffer zone = 280, still very easily enough power. and enermax is not some crappy brand that you can't trust its 300 watts to be 300 watts.

8K7A+ ,does not handle 1/5 PCI divider, so your running your PCI and AGP @ 41.5, way out of spec, you should expect some issues. even at 37(for 148FSB) your close to the line for some PCI/AGP cards. 35-36 is usually pretty safe so thats where i would say your prob is, keep that FSB down to <145Mhz and up your multiplier to 12x. your memory bandwidth will be cut down a bit but your computer will be functional at least.

as for that 1/5 PCI divider, some people get early boards that supported it via a beta bios, but it is not present in the vast majority of boards, and the board is not stable with this beta bios.

Can you tell me where you found the information about the beta boards that supports the 1/5 divider and about the fact that the majority of the 8k7a+'s don't support the 1/5 divider?

I know for a fact that Enermax 300w and 350w have some issues with the 8k7a. Even after hard-modding the 300w Enermax, my 5V rail was barely acceptable (4.71 at load).

 

[blackhawk]

I run an enermax 350w and an antec 350w on my epox motherboards and at default cpu voltage and speed the 5v rails are at 5v but as I increase the cpu voltage and fsb, the 5v rail drops although no lower than 4.8v for my enermax. I now run both cpu's at stock voltage and the 5v is at 4.9x ish for both. When I look at it on post or mbm or in sisoft I see different 5v readings same as different temps & rpms depending on where you read it.

I would think the 300w enermax would be fine at default voltage. I ran an antec 300w on my 8k7a with a 1.4 tbird overclocked and my 5v was always above 4.9


My personal conclusion was that the more power you want to put into the cpu, the more power you needed(amps on the 5v rail) to put into it.
Its strange running my tualitan rig with a 250w ps without any of these issues. Advantage there to intel and one of the cost levelers when I switched to amd.

 

[Brian48]

Dunno about the newer revisions, but I had an 8k7a+ about 4 months ago, it DID NOT have a 1/5 divider even with the latest BIOS.

 

[syadnom]

S0me1X

i did not know of any issue with the enermax PS and 8K7A+, excuse me if thier is an issue.

otherwise, the information on the 1/5 dividers i have from personal experience AND many many time consuming searches on google to find out wy i dont get a 1/5 divider. i have no reference for it except google.

 

[S0me1X]

There are many people with Enermax+8k7a combos with 5V problems (even with Enermax 430w):

http://www.aoaforums.com/forum/showthread.php?s=e7740d7ea6c4280ec346d398c8d12f41&threadid=1267&highlight=8k7a+enermax

http://forums.anandtech.com/arcmessageview.cfm?catid=27&threadid=722291&highlight_key=y&keyword1=8k7a

Of course, there are always some who run Enermax + 8k7a just fine. I've been told that the newer revisions of the Enermax PSUs come with trimmer pots to adjust the 5v rail.