Detecting wrong processor speed at boot.

[pam]

Hi

I have an AMD k6-2 450mhz processor located on a Daewoo CB583M-SI motherboard (pretty obscure I think you'll find).
I have noticed recently that when I boot from cold, it sometimes detects the processor as 400mhz. The bogomips are lower as well, so I have to assume it is actually running at that speed. A reboot usually rectifies things.
I guess this means that my motherboard or cpu is getting a bit flaky but I have no idea how to diagnose where the problem is (and if I could, getting replacement parts might be tricky!).
I can check the voltages at boot time, these are as follows (not taken from initial cold state - I must remember to try and do that):
SMPS Voltage (12v) = 12.10
SMPS Voltage (5v) = 5.12
Logic Voltage (IO) = 3.41
Logic Voltage (core) = 2.16
Is there something on the motherboard that is deciding the processor can't be run at that speed and somehow lowers the clock rate? (heh, you can tell I'm a bit clueless)
Any ideas?

[Schotty]

IIRC, super7 boards had a jumper (either hardware or the now so popular software/bios 'jumpers') for both the bus clock and cpu multiplier. So I would check to see if you can use a hardware jumper to set the 4.5 and 100Mhz. Cuz it appears that a) your clock crystal is dead or b) the cmos is loosing its battery and resetting to defaults.

There could eb a few other reasons, but as for now, the info shown to me makes me think one of those are most likely the problem.

[Compunuts]

It's your battery that is loosing its value. I've had many problems with older mother boards being stored on the shelvs for so long and then trying to get it working. It's highly likely that it's your problem and a cheaper trouble shooting than any other solution.

[pam]

Thanks for the replies

As far as I can tell, the board has hardware jumpers to set the multipliers (it's not the most well documented board in the world, so I make this assumption based on the fact that I can't see any way of changing it through bios settings).
You both say that the battery may be at fault here. If that is the case, then wouldn't I expect to see other non default bios settings being lost plus the date/time?
If my clock crystal is dead, wouldn't that make my system a complete non-starter?
Sorry if I am being thick, me no understand ???

[pbharris]

hey pam,
while it looks kinda strange the battery would a good place to check. BIOS settings can be and most likely are stored in FLASH or an EEPROM. The clock of the MB is also running the RTC - Real Time Clock and that is needed by everybody.

[pam]

Ok, I am not understanding this at a pretty fundamental level, so I will take your word for it (I'm thinking - ok, so no battery needed to keep bios settings, but I am not losing date/time and why does it manage to regain the correct multiplier setting upon reboot?).
All I have to do is figure out where my battery is (hey, stop laughing! )

[pbharris]

ah man... it may be a battery stuck in the BIOS IC....

and that may not be the issue anyway. the date and time being kept is not cool.

[stryder144]

When you open the case look for a large watch-type battery. It's usually near the edge of the motherboard. In your case, it is on top of the isa slots. Check out what the battery says on it then go down to your local computer supply shop and pick one up. Replace the battery and see if it helps things out (it's probably your cheapest option). If it doesn't, then we know it's something else.

CB583M-SI

CB583M-SI
Socket 7
CPU Intel Pentium and Pentium with MMX technology processor; AMD-K5, K6 and K6-2 300~400MHz; 6x86MX and Mll 266~333MHz
100
Chipset Pentium PCI/AGP Chipset, SIS 530/5595B
(RAM) Two 168-pin DIMM sockets for 3.3V unbuffered DRAM module; DIMM sockets support SDRAM; up to 256MB Max(8,16, 32, 64,128 SDRAM)
(Cache) Level 2 512К P.B.SRAM (Built-in Board)
BIOS Award Plug and Play BIOS supports PnP, АРМ and DMI, ACPI & Auto-shutdown support
HDD Two channels of bus master IDE Ultra DMA/33
One Centronics/EPP/ECP parallel port; One built-in 16550 fast UART; Built-in PS/2 keyboard and PS/2 mouse; Two built-in USB port
Three PCI slots and Two ISA slots (One shared)
AGP on board
3D Sound PCI Bus Master (Trident 4DWAVE-DX-1)
3D AGP Video built-in Board 4MB
Wake -on-LAN header
Micro-ATX
Thermal Monitoring; H/W Monitoring (Like LM78)

According to this, you are running a processor that is 50mhz too fast for the max. You can find the Ukrainian page that has your mb's picture here: http://www.abc.kharkov.ua/motherdesc.php?abc=MB044310.


I hope that helps out a little bit.

Cheers


P.S. You might try upgrading the bios software. It may allow for the faster processor. Of course, that doesn't help us to understand why it sees the processor at it's proper speed after a warm reboot. Very puzzling.

[pam]

Thanks Stryder. The system was supplied as 450mhz by the original maker (Daewoo) - this isn't some overclocking exercise by me! (maybe they changed their minds about what they could get away with). The only modifications I have made to the system have been no brainer stuff like extra memory, extra disk space, a cdrw, a meatier power supply to cope with it all...
Anyways, I admit it, I bought it *cheap*, it was not quite cutting edge at the time. I will try the battery avenue - it won't cost me much to be wrong.

[stryder144]

[quote author=pam link=board=3;threadid=4956;start=0#49483 date=1032125103]
Thanks Stryder. The system was supplied as 450mhz by the original maker (Daewoo) - this isn't some overclocking exercise by me! (maybe they changed their minds about what they could get away with). The only modifications I have made to the system have been no brainer stuff like extra memory, extra disk space, a cdrw, a meatier power supply to cope with it all...
Anyways, I admit it, I bought it *cheap*, it was not quite cutting edge at the time. I will try the battery avenue - it won't cost me much to be wrong.
[/quote]

Hey, there is nothing wrong with buying things cheap. I don't understand why Daewoo (one of the largest manufacturers in Korea, btw) would supply a computer with a cpu that the mobo is not supposed to be able to handle. Maybe they updated the bios. Maybe not.

Try searching around www.motherboards.org to find out some stuff about your bios. They have some good info and some nice tips.