AMD TBird 1.2 only clocking at 500 MHz

bobcss427

Distinguished
Sep 1, 2004
6
0
18,510
I know I'm about 3 years behind the technology, but I'm currently in the process of upgrading my older home-built system. It currently has a DFI AK74-EC (KT133 based) motherboard, and an AMD Duron 750. I bought an AMD Thunderbird 1.2 GHz (200 FSB) processor and after installing it, only see it showing 500 MHz in BIOS and in Windows XP. I played around with the BIOS settings (including the voltage), but have had no luck at all. Other than running at 500 MHz, it does seem to run fine, and the CPU temperature is running in the mid 30's.

I put my Duron back in, and it immediately runs correctly at 750 MHz.

Any ideas if I may be doing something wrong? I'm now assuming that I got a bad chip (it was new, OEM packaged from StarMicro).

Thanks in advance for your help,
Bob
 

blackphoenix77

Distinguished
Jan 10, 2004
1,130
0
19,280
Is there a "User Define" in your BIOS when you have your Tbird in there? If there is, you might want to try manually setting the multiplier and FSB.

<font color=blue>AthlonXP-M 2500+(12x200)</font color=blue><font color=green>Abit NF7-S</font color=green><font color=red>Kingston DDR400 2x256Mb</font color=red><font color=orange>NEC Accucync 19" CRT</font color=orange><font color=black>Sapphire 9600XT</font color=black>
 

bobcss427

Distinguished
Sep 1, 2004
6
0
18,510
Thanks for the quick reply!

I don't recall seeing "User Define" in my BIOS. I've heard that DFI motherboards aren't too good when it comes to playing with CPU multipliers (and I haven't seen anywhere where I can change this).

I do see the CPU show up as "AMD Athlon 500 MHz (5X100)".

I haven't tried raising the FSB yet, since I would think that even at 100, I should see 1.2 GHz (12X100).

The only other thing I've noticed is that it doesn't always boot up (don't even think it POST's) with this new CPU, and my monitor flakes out for some reason. My case was pretty decent when I bought it, and the power supply is at least a 300 watt one.
 
Make sure you're running the latest BIOS for that board... perhaps all the multipliers are available.

<font color=red> If you design software that is fool-proof, only a fool will want to use it. </font color=red>
 

phsstpok

Splendid
Dec 31, 2007
5,600
1
25,780
I doubt you have a bad chip. It wouldn't even POST at 500 Mhz if it was bad.

Try upping Vcore to 1.8V or even 1.85V if your motherboard can do that. You will need a decent heatsink. Tbirds are notorious for heat.

Most of the the KT133 motherboards needed a BIOS update at some point before they could even run the old Tbird 1100's (200) and up. Find the latest BIOS for your motherboard and flash your board.



<b>56K, slow and steady does not win the race on internet!</b>
 

endyen

Splendid
It sounds as though the mobo doesn't recognize the chip, so it is defaulting to 500. Zoron is probably right, you need a newer bios. <A HREF="http://www.dfi.com.tw/Support/Download/bios_download_us.jsp?PRODUCT_ID=1273&STATUS_FLAG=A&SITE=US" target="_new">http://www.dfi.com.tw/Support/Download/bios_download_us.jsp?PRODUCT_ID=1273&STATUS_FLAG=A&SITE=US</A> It also may be the issue addressed by bios dated Nov 29/00. Get the latest bios anyhow.
 

bobcss427

Distinguished
Sep 1, 2004
6
0
18,510
First off... today being my first day ever on these boards, you guys are great, thanks for all the replies!

I applied the latest BIOS from DFI (I was one rev. behind), and some progress was made, although I don't know if its better or worse now.

It now shows up as an "AMD Athlon 4 504 MHz (36 X 14.0)". I set the voltage up to 1.850, and also explicitly set the FSB to 100/33, but it continues to show this slow speed (which I assume is now being caused by the low FSB speed). Raising or lowering the FSB speed does affect the speed by a factor, i.e. 95/31 takes it down to 494 MHz or so.

I tried loading the fail safe default BIOS settings, and also the optimal settings, all with the same 504 MHz result.

Mind you, this motherboard has been flawless for 3+ years with a Duron 750. I have never played with any of these BIOS settings before today.

Any other thoughts before I send this CPU back?

Thank you all again for all the suggestions!
Bob
 

endyen

Splendid
The weird part is the
It now shows up as an "AMD Athlon 4 504 MHz (36 X 14.0)".
It's saying your fsb is 36 and your multiplier is 14. Neither of those should be right. Do you have sisoft Sandra? It should tell you what speed your chip is running at. If you dont have it, google for it, and get the free version.
 

bobcss427

Distinguished
Sep 1, 2004
6
0
18,510
I don't have sisoft Sandra yet, but I did boot into XP, and the sys. props. show it at 500 MHz, along with PCPitstop. From the way its running, it does only seem like 500 rather than 1200.

My question now is why after updating the BIOS to the latest did it go from "100 X 5.0" to "34 X 14.0"? It almost seems like the chip just doesn't wanna clock at anything over 500 MHz.

Someone mentioned that the CPU cannot be the culprit, since if it were bad, it would never even get past POST. But at this point I'm at a loss.
 

phsstpok

Splendid
Dec 31, 2007
5,600
1
25,780
I'm stumped too.

500 Mhz is the fallback speed for many Socket A motherboards when they can't POST at the CPU's default speed but 36 x 14 is interesting. My guess is the BIOS just does a simple calculation, taking the clock speed, 500 Mhz, and divides by a multiplier, 14X (though I don't know why 14X).

BIOSes often get confused. When I was playing with the multiplier remaps of a Tbred B on my KT133A mobo one of the combinations that came up is 256 x 1. It was supposed to be 100 x 23, which it really was just misreported. (23X is the remap from 10X but I'm off the subject now)

Perhaps you should look at the identifing numbers on your CPU to verify which Athlon you actually have. I'm wondering if you really have an Athlon 1400 (because of the 14X).

There are other things you could try but you probably don't want to do this you plan to send the chip back.

You could unlock your processor with the old "Pencil Trick" then you could set lower multipliers. If you are then able to run the processor at say 10x then you probably just have a stability issue, as opposed a true conflict.

What brand/model/power rating is your power supply? That Tbird 1200 will draw a lot more power than your Duron 750. Post the +3.3V/+5V/+12V ratings, listed on the side or top of most power supplies.

<b>56K, slow and steady does not win the race on internet!</b><P ID="edit"><FONT SIZE=-1><EM>Edited by phsstpok on 09/02/04 12:53 PM.</EM></FONT></P>
 

endyen

Splendid
Yes, check the top of the chip, to make sure it's not a 1400. That would explain a lot. The mobo, doesnot recognize the chip, so it defaults to 500mhz, using an fsb that, with the multiplier, yields default speed.
 

bobcss427

Distinguished
Sep 1, 2004
6
0
18,510
OK, two more updates on this issue... I just can't bring myself to give up and return the CPU yet.

One other problem that occurs every time is when I turn the system on, nothing happens, no POST, nothing. The only way to get it to boot up is to use the reset button. It can then be reset/rebooted fine every time, its only that initial power up. I unplugged every hard and optical drive to see if it may be a power issue, but am getting the same results.

The other thing is that it shows up as a "Mobile AMD Athlon 4..." processor. Is there a difference between the mobile and desktop versions? Additionally, there is a sticker on the chip that says "Replace with Compaq spare, 277514-001". The actual AMD part number on it is AHM1200AHQ3B.

Finally, the power ratings on the 300 Watt case are...
+5V 25A
+3.3V 14A
+12V 10A
-5V 0.5A
-12V 0.5A
+5VSB 1.5A
 

phsstpok

Splendid
Dec 31, 2007
5,600
1
25,780
A quick Google search verified that your AHM1200AHQ3B CPU is indeed a Mobile Athlon 4.

According to <A HREF="http://myplc.com/sony/docs/amd_processor_reference.html" target="_new">this table</A> the Mobile Athlon 4 was a low power Palomino class processor, running at 1.55 Volt.

This information doesn't help you get it working, though.



<b>A mind is a terrible thing</b>
 

bobcss427

Distinguished
Sep 1, 2004
6
0
18,510
I know its been a few weeks, but I wanted to make sure and thank everyone for their help. The problem ended up being the wrong chip, they sent a mobile version for my desktop. The bonus is that they sent me a 1.3 desktop version instead of a 1.2, and it works flawlessly, although the temp is much higher than the Duron 750 (low 60's vs. low 40's).

Thanks again, this is a great place for answers... I'm sure I would've long given up without everyone's help!

Bob
 

phsstpok

Splendid
Dec 31, 2007
5,600
1
25,780
Yeah, Morgan Core Durons run hot but at least you have a working upgrade.

Don't know what HSF you are using now but there are plenty of good and cheap ones these days that should let you run a Duron 1.3 at 50 degrees or lower without too much noise.

<b>A mind is a terrible thing</b>