CMOS Setup Utility - AMD Athlon/Duron Multiplier Factor

[Guest_imported]

I'm a bit confused here, and I want to get a few things straight before I power up my new System. I've decided to go with AMD over Intel since there have been more favorable reviews throughout the years. What's the whole factor on AMD chips running on 200/266Mhz FSB? For example; when I'm in my CMOS Setup Utility program, it will tell me the following information (this is just an example):

CPU Name is: AMD Athlon (tm)
CPU Operating Speed - 500 (100)
x - Multiplier Factor - x5
x - CPU FSB Clock(Mhz) - 100
x - FSB Rate (CPU:SDRAMCI) - 3:3:1
x - Speed Error Hold - Disabled

CPU speed = External clock *Multiplier factor. For AMD Athlon and Duron processors, you can choose the following settings:
>User Define >500(100) >550(100) >600(100) >650(100)
>700(100) >750(100) >800(100) >850(100) >900(100)
>950(100) >1000(100) >1000(133) >1050(100) >1100(100)
>1130(133) >1150(100) >1200(100) >1200(133) >1400(100)
>1333(133) >1400(133)

What are all these specs for? I'm assuming 500Mhz, 100FSB? How do these settings apply to AMD if their chips are 200/266mhz FSB. I'm getting this info off my ABIT RAID KG7 Mobo. Currently, I have a 600Mhz AMD Duron. So what settings should I put it on!?

Joel

 

[osuman]

Depending on the model of the chip, the multiplier is usually locked. Intel has been doing this since the PII's were out. The reasons are pretty much economically based not technically. Nonetheless, even if you change the multiplier manually in your CMOS, it will remain locked because it's hardwired on the chip itself. Therefore, the only real way to change the clock speed of the CPU is to change the FSB. The reason you board doesn't have settings for 200/266 is because it doesn't support it. If you have an AMD 600 then most likely it's multiplier is locked at 6 assuming you will clock your FSB to 100mhz. It also looks like your CMOS understands this and there for gives you the choice of what you want your FSB to be and what the CPU will clock at internally.

 

[Guest_imported]

I'm still confused though. This KG7 RAID is designed for AMD Chips only. For example, I have an AMD Duron 600Mhz, and the FSB for a Duron at this speed is at 200Mhz right? Therefore, shouldn't my Multiplier Factor be x3? Since 3 times 200FSB equals a CPU Speed of 600Mhz.
I'm assuming, 200Mhz/266Mhz have no signifance since multiplier factors still go by 100/133 right?
Lastly, let's just say that my Duron 600Mhz has a FSB of 100Mhz (which doesn't make sense since it's an AMD chip, and not Intel), and my Multiplier factor is x6; then this would mean 6 times 100FSB = CPU 600Mhz. This makes sense, but doesn't that only apply to Intel Chips since Intel goes by 100/133 and 400Mhz FSB?

 

[Guest_imported]

I see, I went to ABIT.com and got some info for the Mobo. This is what I conjured up:

CPU
1.Support AMD Athlon 700MHz ~ 1.33GHz or future Socket A Processors based on 200/266 MHz(100MHz/133MHz Double Data Rate)
2.Support AMD Duron 600MHz ~ 950 MHz or future Socket A Processors based on 200 MHz
(100MHz Double Data Rate)

Is this what I should be understandind? Can someone explain this to me. So if I put in my Duron 600, does my Mobo set it at 100Mhz FSB, and then automatically work it at 200Mhz FSB? Am I right, or what am I not understanding.

 

[osuman]

Your 600mhz chip has a multiplier of 6 with an FSB of 100mhz. (I'm not sure why you thought it was 200/266 for AMD and 100/133 for Intel.) Anyway, the bus to the processor is 100 mhz but it sends data on both sides of the clock cycle. The way I understand it, this is referred to as double-pumped. I read a detailed description of how this works but it lost me. I guess you have to have an EE degree to really understand how it works these days.

 

[stuartd]

It is all marketing talk - 200/266MHz is really 100/133mhz, but doubled-data rate as Osuman stated, the '400MHz' Intel bus is really 4*100MHz pipes (therefore 400MHz).

Anything to fool the end users right?

 

[Jakespeare]

Man, I hate to even get involved in this. However, I would suggest to everyone who is confused, to do research on the Internet; there you will find all the basic info that you will need to have these questions answered.

*BTW: It ain't all marketing talk. These are system / hardware specifications. There is a difference between:
> 1) THE SYSTEM BUS ( 100/133)
2) FSB (200/266)
(oh, and don't forget the PCI BUS = 33 MHz)
( and, the AGP which is 66 MHz)

So, you can have a system with a 1333 MHz CPU (ATHLON).......
which runs at .........
> 266 FST
> 133 MHz RAM
> 66 Mhz AGP
> 33 MHz PCI


Front Side Bus ..... ain't marketing hype.

> I like Anandtech, but it's really not for the novice. However, you can find lots of tech articles (as I stated all over the NET).

http://www.pcguide.com

etc.

Have fun.............

 

[CitrixEngineer]

As someone said, ask 10 techs the same question and you'll get 12 answers.

Some of this IS marketing talk.

The FSB for Athlons is dual-piped (or double-pumped, as a lot of l33t sites like to describe it), but IS 100/133Mhz. Because it's dual piped, you EFFECTIVELY get 200/266Mhz FSB, which means that the processor can take twice as much data as the PCI bus can provide. This is useful if the processor gets caught in loops, or has to deal with quantities of dirty or faulty data. There's much more to it than this, of course.

In much the same way, the FSB for Pentium 4's is quad-piped. As you can see from the extremely basic outline I've given above, there's really not much advantage in that, which is why Athlon and P4 performance is so close at the same internal speed (the speed the chip is marketed at).

A modern AGP bus has a 4x multiplier, and hence can effectively run 4x66 Mhz. Internally it's even faster. 533Mhz, if I remember correctly.

33Mhz is the original PCI spec. If it was still 33Mhz, there would be no point in ATA66/100/133 disk controller systems. Again, a clever system of multipliers is at work, bringing the effective speed of the PCI bus up to 133Mhz. There's a magic number at work here ;-)

There is tons of information out there, but I'm happy to translate the really scary stuff into plain English if anyone wants more detail.

I hope this is useful

CE