Why won't my system correctly recognize its processor and clock speed?
March 11, 2004 7:17 PM   Subscribe

I recently purchased an Athlon XP 2400 266 FSB, to replace my Athlon Thunderbird 1.4ghz. Running at 133/133, the processor only shows up as a 1700 running at 1.49ghz. I have an ECS K7S5A with the Cheepoman BIOS (and I've tried this with the latest ECS BIOS as well). I've seen people talking about this combination being okay for them, but I can't for the life of me figure out why this won't recognize it as the right processor and clock speed. Bumping up the CPU speed to 166 causes my system to not boot. I've confirmed through the numbers on the processor itself that it is indeed an Athlon XP 2400. What else could be at fault here?
posted by angry modem to Computers & Internet (14 answers total)
Try using CPUID to identify what the CPU actually thinks it is deep inside. There's windows utilities out there to do that; under linux you can just do cat /proc/cpuinfo.
posted by fvw at 7:31 PM on March 11, 2004

I've had a situation much like angry modem's but I haven't cared enough to investigate. But now I've just did cat /proc/cpuinfo and it says the CPU is a 1347 Mhz athlon but my memory tells me that it really is a 2220 Mhz Athlon?
posted by rdr at 7:52 PM on March 11, 2004

Things you may all find handy:


Me thinks the motherboard be out of gas, my friend. :-)

rdr, your bus is set incorrectly. It is at 100 and should be at 133. Enjoy the free speed boost.
posted by shepd at 8:21 PM on March 11, 2004

rdr: Look at the modelname line, not the cpu Mhz. The former is the chip's spec, the latter is what it's actually running at.
posted by fvw at 11:48 PM on March 11, 2004

I know this may insult you, but you are using 333FSB RAM, right?
posted by Keyser Soze at 11:54 PM on March 11, 2004

Well, let me reiterate: 266Mhz RAM. Heres a review of your motherboard: http://www.sysopt.com/reviews/ecs-k7s5a/
posted by Keyser Soze at 11:59 PM on March 11, 2004

I've had exactly the same thing. I put together an XP2400 on a KT400 motherboard late last year, but have never been able to get it to run at more than XP1800 speeds (1.5ghz). Bumping it up to 2ghz (by increasing bus speed from 100mhz to 133) kills it, and I have to open up my pretty blue case and reset the BIOS (bumping it back down to 100Mhz FSB) before it'll start up again. My RAM is 266Mhz.

I suspected it was a CPU voltage issue, but at the moment I did that I realised I was massively out of my depth, so I just left it. Returning the parts to the online shop would have cost me a lot, and I didn't want to keep fiddling and accidentally fry £100 worth of kit.

I'll download the CPU ID jobbie when I get home from work and see what it tells me.
posted by ArmyOfKittens at 4:30 AM on March 12, 2004

Well, let me reiterate: 266Mhz RAM. Heres a review of your motherboard: http://www.sysopt.com/reviews/ecs-k7s5a/

Yes. Not insulted. Gotta ask people insulting questions to make sure :)

I'm thinking that I need to get a different motherboard, at this point. Using WCPUID tells me the multiplier is only 11, while it should be 15.
posted by angry modem at 5:37 AM on March 12, 2004

If the multiplier is 11 and the fsb is 133 the total speed should be 1463.

Since the ECS k7s5a can't change multipliers itself, your cpu is borked if the speed is indeed 1463.

If the speed is 1500 +/- 10 mhz then I'll bet that your mobo is really running at 100 fsb with a 15x multiplier on the cpu which is what the default multiplier for a 2400xp is anyway.

1463mhz = CPU multiplier messed up. Possibly mismarked.
1500mhz = FSB running at 100mhz and not 133mhz.
posted by yangwar at 7:34 AM on March 12, 2004

1463, indeed. I'm leaning towards mismarked, though I might not bother with RMAing it because of the hassle. So instead maybe I'll overclock it. :P

I bumped up the FSB to 150/150 using the Cheepoman BIOS, so I'm running it at the XP 2000 level of 1.65ghz. 166/166 is unstable from what I understand, and it won't boot at that level and higher, so I'm stuck for now.

Thanks for the help, guys.
posted by angry modem at 9:11 AM on March 12, 2004

WCPUID says this for me: that I have an Athlon XP 1800 running at 1500Mhz on a multiplier of 15 and an FSB of 100Mhz. If I understand what yangwar said, that means I've probably got a genuine XP2400 like it said on the chip when I installed it, and it's the motherboard that's misbehaving.

So that means I should up the FSB to 100Mhz, yes? I've done this in the past, but having done so the PC won't boot, won't even POST; it just sits there, fans whirring, network lights on, but no-one home.

I know I'm missing something. Is there another setting I should be changing at the same time at the FSB? CPU voltage, memory timings, or anything else that the motherboard should auto-detect, but hasn't?

I've got this upgrade kit, for the record. As an XP1800 it's running fine and it's totally stable, but as long as I'm not going to blow it up I'd like to get it going at the full 2Ghz, XP2400 speed. Half Life 2 is coming out, after all.
posted by ArmyOfKittens at 9:22 AM on March 12, 2004

>So that means I should up the FSB to 100Mhz, yes?

133 Mhz... that is. :-) You're at 100 Mhz right now.

If you go too high and it crashes / won't boot it's as simple as either putting the jumpers back to their original position or clearing the CMOS (that will be detailed on the motherbaord and in your manual).

The important thing: After it's run for a bit, do the finger heat test. Lick your finger and touch it to the heatsink. If it doesn't sizzle and isn't burning, you're A-OK. :-)
posted by shepd at 10:14 AM on March 12, 2004

That's great, I'll give it a try right now. Hopefully I won't singe my fingers too badly :)
posted by ArmyOfKittens at 10:29 AM on March 12, 2004

I just put it up to 133Mhz (also: I need to read the preview text more thoroughly...duh), and will it work...?

No, sadly it's doing just what it did a few months ago: all the fans and drives start up, but nothing happens on screen. I've switched it off, opened it up, cleared the BIOS, and I'm now giving it the fifteen minute recovery time it needs before it'll deign to boot again.

(That last bit's so weird, because it comes back in stages: the VGA BIOS in the first five minutes; in the next five minutes it'll get as far as the BIOS logo and motherboard ID string; and five minutes after that it'll POST and everything is fine.)

Thank goodness for thumbscrew-release cases.

On this showing, it doesn't look like it'll ever boot at 2Ghz. It's no big worry; in a couple of months the board and CPU can go in my ugly workhorse PC that hides in the corner (currently a Duron) and I can get a nice quick new set of bits (from someone other than Savastore) to go in the pretty case that sits by the TV.
posted by ArmyOfKittens at 10:55 AM on March 12, 2004

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