AMD builders...valuable info, read!

[RainMan]

Running the new 266FSB Athlons in KT133 MBs

The new 266MHz Front Side Bus ( FSB ) parts will boot in a KT133 MB, however they will come up as a lower speed Athlon processor than they are marked.

The reason for this is the Athlon processors use the FSB Clock provided by the MB,and multiply it up by fixed multiplier inside the chip. The FSB Clock is 100MHz in the case of the KT133 MBs and 133MHz in the case of the KT133A and AMD 761 MBs. Take a 1GHz/266FSB Athlon for example. This part would have a 7.5X mulitplier since 133.33MHz X 7.5 = 1.0GHz. If this part were to be plugged into a KT133 MB with an FSB Clock of 100MHz it would boot up as a 7.5 X 100MHz = 750MHz Athlon. Not a good deal. Hence, the new 266FSB Athlons must be used in KT133A or AMD 761 MBs that have the ability to run with a 133MHz FSB Clock.

Incidentally, the 200MHz and 266Mhz FSB number comes from the FSB Clock multiplied by the Double Data Rate of the FSB of 2. 100MHz FSB X 2 = 200MHz Data Rate and 133MHz FSB X 2 = 266MHz Data Rate.

A 1133MHz/266FSB Athlon in a KT133 MB would come up as an 8.5 X 100MHz = 850Mhz

Athlon and a 1.2GHz/266FSB Athlon in a KT133 MB would come up as a 9.0 X 100MHz = 900MHz Athlon.

200MHz FSB Athlons will run in the new KT133A & AMD 761 MBs since all KT133A & 761 MBs can run at either 100MHz FSB or 133MHz FSB. However, 200MHz FSB Athlons will not run in KT133A or 761 MBs with their FSB Clocks set to 133MHz.

Lastly, the way to tell the difference between a 200MHz FSB Athlon and a 133MHz Athlon is by looking at the part number which is on second line on the chip. The 200MHz parts have a B at the end of the part number whereas the 266MHz parts have a C at the end of the part number. Further information regarding interpreting the part number may be found in the Athlon and Duron Data Sheets in the Ordering Information Section. These data sheets may be obtained from the AMD website at http://www.amd.com .

[akbar]

LOL... i didnt read ur whole post, but i can assure you that new amd builders arnt buying mobos with the KT133 chipset, atleast on sharkyforums .

[RainMan]

I'm soory...I did not realize you knew exactly what everyone was doing here, what everyone plans were and what all the problems were...you are a bright guy.

Hurry up before you miss your bus....weener.

[Adisharr]

Originally posted by RainMan:
I'm soory...I did not realize you knew exactly what everyone was doing here, what everyone plans were and what all the problems were...you are a bright guy.

Hurry up before you miss your bus....weener.

How dare you try and bring valuable news to this forum!

Shame..


------------------
- Ducks go quack -

[Un4given]

This information really has been known for quite a long time. The same information applies to Intel's EB (133MHz FSB) P3's and boards only supporting 100MHz FSB.

------------------
Earl of the OC Crusaders

P3 700@980 (140x7.0 1.85V--dropped from 1001 to o/c video higher)
Abit VH6-II w/256MB PC150 (2-2-2)
Radeon 64MB VIVO 205/205
SBLive! Value
13.5GB & 30GB Maxtor ATA100 (5400RPM)
Memorex 36X CD-ROM/TDK 8x4x32 CD-RW

[RainMan]

Fair enough....I guess just keep in mind that a lot of us are new to this racket so what is pase' to the old school is fresh to the noobs.

The real reason behind this post is that the market is being flooded with a great "barebones" system that comes with a case/mb/floppy/56kmodem/cables for 99.00

It is really a Micron case/mb combo and is getting very very positive reviews. They are selling out faster them you can get your hands on them. They advertise that it will run a 1.2 AMD T-Bird...but they don't say to use the 200 fsb, not the 266 version.

Hence there are a lot of guys out there wondering why their 1.2 T-Birds are showing up as 900 in the system post.

I bought one of the combo's and it truely is a great deal (has onboard sound as well)

Regards

[russ_watters]

This has been an issue since the invention of the clock multiplier in like 91 or so. If you put *ANY* new proc with a different fsb expectation than your old one on your old mobo, you have to make sure the fsb (and multiplier) are set right. On older motherboards, both were set by jumpers on the motherboard, then came bios settings, then came locked multipliers. And thats why most people today oveclock with the fsb - besides the fact that it yields better results - its often the only way to do it.

There are a handful of boards (like my FIC SD11) that don't allow you to change either, but instead detect what the cpu needs. Expecting EVERY motherboard to do this is a common mistake.

[Squirrel Meat]

well rain man, at least i can say that i can tell you wont be one of those useless spammer guys. you have a lot of usefull information and i look forward to hearing from you more!

------------------
Never trust consumable rodent flesh.

My Rig:

http://www.beam.to/compspecs

[jagojago12]

Also, while not very official, 200FSB Athlons and Durons can run at 266FSB if you unlock them and lower the ratio.

A 1GHz/200FSB CPU can be unlocked from 10x multiplier to 7.5x.

------------------
"There is no gain without sacrifice. Great sacrifice means great achievements."

AMD Athlon XP [email protected] (10.5x133)| EPoX EP-8KHA+| 256MB Crucial PC2100 CAS2| VisionTek Geforce3 Ti200| Sound Blaster Live Platinum!| 80GB 7200RPM Western Digital| 4x/4x/24x LG CD-RW| 5x TOSHIBA DVD-ROM| 19" NEC AccuSync 90