Athlon 2700+ being seen as 1500+

While trouble shooting some other problems I've been having with a video game, I noticed something very strange. The AMD Athlon 2700+ I have is registering as a 1500+. During the system boot up it recognizes the proccessor with only an ID.

Anyone seen this before?

 

Suggest you look in the BIOS to see what the hardware thinks the CPU is, and if necessary check the manual to see if you can correct it.

 

Check your FSB - it should be set to 133 MHz, seems its set to 100 MHz.

 

On the way....

Thank you,

I just changed the CPU clock to 133 and it now registers as a 2100+. Could you tell me more about what this number means? Is it wise to raise the number higher or should I make do?

Oddly enough, this seems to have solved my mouse problem, which I posted about, as well. Or at least it seems like it.

Append: The mouse solution was short lived. After 3 or 4 boots with the new setting, Windows told me I needed to use scandisk, and then the problem returned.

 

FSB = Front Side Bus. Its the path thru which the CPU talks to rest of the computer (approximation). FSB speed is the speed at which it does it.

CPU Speed = FSB Speed x CPU Clock multiplier.

On most of the CPUs, the clock multiplier cannot be changed & so the overclocking options are limited. You could raise the bus speed a little at a time (in increments of 0.5 MHz or thereabouts) & test if the computer still works ok but your motherboard has to support it.

 

The same thing happened to me about a 2700+ Athlon reporting as lower speed (2100 as I recall) even though bios settings appeared OK. There are other accounts on the web showing this situation also, but I have never seen a resolution. My situation happened after a motherboard failed in which I replaced the motherboard with an essentially identical version. The reinstalled CPU registered at the lower 2100 speed and nothing I did would seem to get it back to the original rating. Other spare Athlons I had did register properly in the new board so I came to the conclusion that I had somehow damaged the 2700+ CPU in my original board failure. I never trusted that Athlon again and soon replaced it with a 2800+ Barton which is still working OK.

Good Luck
Top Dog

 

And that was pretty much my conclusion from the begining. I had a very strange failure which I never figured out how it fixed itself. The tweeter on the mother board started beeping once a second after the CPU overheated. I switched everything, graphics cards, sound cards, wiped the hard disk, and even swapped the mother board and the beeping didn't stop. When I swaped the mobo back again, it mysteriously stopped. Now my processor is acting up.

I just don't know if it's worth spending the money on a Socket A though. I'm thinking I may wait to put together a new system.

Thank you all for the help.

Also I can't change the FSB, I can only change the CPU clock in bios.

 

I believe that you won't be able to find new Socket A CPU, even if you want to. AMD stopped manufacturing them moons ago.

Most motherboards have a jumper to set the FSB, but CPU clock can be set in BIOS.

 

I don't feel that I'm jiggy with some of the assessments in this thread about Athlons registering at the wrong speed (not with the tech. info provided by Rsinfo).

When you install a cpu into a mainboard, you should either go into the BIOS and select Optimized Settings or manually set the FSB setting (e.g. 133Mhz) and set the multiplier (e.g. x12).

Selecting Optimized Settings will have the bios automatically detect the cpu and will correctly set the FSB and multiplier. Another way to do this is to clear the CMOS which will, most likely, cause the cpu to be automatically detected.

Most times, after these steps are taken, if the cpu is still not recognized correctly, it may be that the cpu itself is not recognized by the bios and it's taking a guess on the FSB and multiplier. That can sometimes be remedied by a bios flash. Sometimes your cpu and mainboard are simply incompatible and that's that.

Regarding jumpers, even with Socket A boards it was rare that I had to deal with one that had a jumper for FSB. Usually, everything was handled in the BIOS.

Gary

 

Athlon 2700+

I agree with Chiles4 that it is hard to be more helpful without knowing which motherboard you have, Bios version.

However, the first problem is that you need to set the FSB at 166 not 133.
The 2700+ is a 333 FSB processor. Setting the FSB at 133 makes it read like a 266 FSB processor and it will show up in the bios as 2100+.

 

This happened to my wife's computer also. It kept dropping the CPU back to 1200 even tho it's a Athlon 2000... I bought a new mobo and it still would only boot as 1200. After about a month the machine stopped running. Somehow the CPU died! I replaced it with a Sempron 2400 socket A (from NewEgg) and the system works fine now. Seems Athlon is sensitive to overheating and will somehow drop back to a lower operating freq if it can, to keep running...

I still don't know why the 2000 died, her machine never ran hot and I'm still using the same heatsink/fan on the new Sempron... I think the Athlon 2000 may have been defective.

 

I have an older (MSI) Socket A board (MS-6738) that has jumper settings for the FSB. I think it you can set it for either 100 or 133mhz, FWIW.

 

maybe me too

I ordered an alleged Athlon 2800+ months ago (OEM) and finally got around to installing it. It is recognized as "unknown 1300MHz ". Able to raise to 1500+ in BIOS but higher and the box won't post. Guess I got taken-too late to ask for a refund. How can one be sure that a processor is what it claims to be?

 

Success!!

Well thanks guys! From what you said, I dug out my old MB manual, it is an MSI MS-6390, and has a jumper to change CPU FSB Clock. Changed it from 100 to 133, and....whalla! it now reports as 1.75GHz, still "unknow ", but thanks for your help.

 

For AMD 2700+/2800+, you need to set the FSB to 166 MHz but only a few boards support this as 100 & 133 MHz are the most common. I think you need a nForce2 board to run this CPU properly.

 

Careful here - some of the 2800+ Athlons were 266MHZ (133x2). The Thoroughbred (266MHZ) runs at a 2.25Ghz but the Barton (333MHZ) runs at 2.083Ghz. There are a lot of once very rare 2800+ Thoroughbreds being sold today and some of the oldest Socket A motherboards won't recognize them. You will find identification on the core itself or on a sticker on the top of the chip if its an authentic AMD processor. It may be wise to investigate BIOS revision histories for your board and possibly consider flashing to the latest revison or at least something that recognizes your processor. And, if you have a 2800+ XPM, it may not ever be recognizable other than by Ghz. Unfortunately, I don't know much about your board.

 

Hey, that's good news!

MSI has a special forum for people with their mothersboards. Check it out...

http://forum.msi.com.tw/

 

Yes, it appears that your mainboard is much older than your cpu.

Gary

 

That's true. I think I saw where my board's BIOS has to be flashed in order to run a certain CPU.

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Here's some cpu info for Leonard's board that I dug up, FWIW...

http://www.msi.com.tw/program/products/mainboard/mbd/pro_mbd_cpu_support_detail.php?UID=80&kind=1