AthlonXP Multiplier Limits?

Please forgive me if this has been asked 1000 times but I'm new to overclocking the Athlon XP chip and have some questions.

I know that by unlocking the multiplier for the FSB on an AthlonXP you effectively speed up the clock (multiplier X FSB speed= clock frequency).
My question is say you have an XP1500 or XP1600. Can you unlock it and make it run as fast as an XP 2000 or a 2100? What is the limiting factor here. If this is possible than why aren't people just buying the slower chips and overclocking them? This would save a lot of money from buying a more expensive faster version of the chip. I know heat is a huge factor but ignoring that fact what is the multiplier limit?

Like I said I'm trying to learn this so be patient. I'm in the process of building my own system and want to know whether to buy the faster chip or just get a slower and overclock it. I need some expert advice. Thanks in advance! By the way I mistakenly double posted this under another thread here by mistake. I'm new here and learning.

Don

I would try upping the Fsb without unlocking the chip, the fsb is what will make more of a diffreance than upping the multipliers as it will speed video card and so forth, you may be suprised how far you can go without unlocking it, You will most likely get higher Fsb by unlocking and lowering your multipliers and raising the Fsb way up. I am able to get up to 152 fsb with my Xp2000+ locked

donfm said:

I know that by unlocking the multiplier for the FSB on an AthlonXP you effectively speed up the clock (multiplier X FSB speed= clock frequency). My question is say you have an XP1500 or XP1600. Can you unlock it and make it run as fast as an XP 2000 or a 2100? What is the limiting factor here. If this is possible than why aren't people just buying the slower chips and overclocking them? This would save a lot of money from buying a more expensive faster version of the chip. I know heat is a huge factor but ignoring that fact what is the multiplier limit?

Click to expand...

No you can not. Your arguement is under the premise that all CPUs are the same & that the manufacturer have decided to cripple a number of their chips to be sold as slower models. If this was completely true you would see massive O/Cs from the slowest model without heat & voltage issues & run completely stable.

Yes there is a possibility to do that. CPUs are made in batches & some of them can reach higher clockspeeds well over normal speeds with added voltage & cooling. That is one reason why people look for certain steppings since they offer a clue to what the possibilities of that batch hold.

Now to you multiplier question. The XP1500+ - XP2000 have multipliers, when unlocked, from 5X to 12.5X. The XP2100 & up have multipliers from 13X to 20.5X. There is a set of bridges asides from the more commonly talked about L1 Bridges that allow the higher multipliers which are the L10s. Modifying them will give you control of either set of multipliers but not both.

Thanks Sonny, you answered my question. The multiplier is higher on the faster chips. I assume this also means the heat is higher as well. Sorry about the double post I already asked to have the duplicate removed.

Welcome to the Forum

Just to give you some more insight as to why you cannot overclock the slower cpus...

The CPUs are "bin sorted" that basically means after they are made they are tested at various speeds and if they are not stable at xp2100 speed then they will be tested at xp2000 speed. If its stable at xp2000 speed then that is what it will be sold as (perhaps a cpu that will run at xp2000 speeds is actually sold as an xp1900 to gaurantee stability, this is just an example of how its done).

That also explains why some chips will overclock better then another, even if they are from the same batch/stepping. it is possible that a cpu that was stable at xp2100 speed could be accidently labeled xp2000 or vise versa.

some people have xp1600s and overclock them to 1800mhz, while others have xp1800s and cant get them past 1700mhz. as you mentioned heat is also a limiting factor, as is voltage which causes more heat.

As for what to buy, I think you should go with an xp1800-2000 unless you can afford to go with the fastest. keep in mind that unlocking an xp2100 or xp2200 is much more difficult then unlocking an xp2000 or less (that ties in to what sonny said about the L10 bridges). you should be able to get at least a 200mhz overclock with good cooling but you may only get 100mhz. look for steppings like AROIA and AGOIA, they seem to overclock quite well.

Post back if you have any more questions.