CPU Ratio settings and more !

Hi,

Just to explain before i go on, i know nothing about "cpu ratios" and "host clock setttings" so please go easy on me

I currently have a jetway v266b mobo running an xp2000+ and 256mb 2100ddr.

On visiting the jetway site they say the v266b will run with an xp2600+ processor. Now im not thinking about buying one, i would just like to understand how this board could run with this cpu.
Jetways list of supported CPUs (v266b)

I understand the 2600+ comes in 2 flavours a 133(266ddr) & 166(333ddr) is that right ?

Now this is where i get totally confused..........

The v266b has a fsb of 133(266ddr).

And there are jumpers on the mobo to set the "cpu ratio" which go from x5 upto x12.5

My xp2000+ is running @ 12.5 x 133 = 1662.5mhz

There is also an option in the bios to alter the "Cpu host clock" which goes from 133 to 166.

So the question is "how can you run an xp2600+ with this mobo ?"

Would'nt the cpu ratio need to be 15.5 x 133 = 2061.5mhz
(if the CPU is 133)

or would you do 12.5 x 166 = 2075
(if the CPU is 266)
(you get 166 by upping the "cpu host clock" in the bios).

Here is the v266b spec sheet from the jetway site

Now i know im bound to be totally missing the point somewhere. Im sure jetway know which cpus work on their mobos but this doesnt make any sense to me

Oh, and one more thing before my head explodes trying to work this out.......

I visited the Crucial site to find out how much 512mb of 2100DDR would cost and their "memory selector" tells my the v266b takes 2100ddr and 2700ddr ?

I thought 2700ddr was for 266(333) mobos ?

As you can see im a bit lost with all this stuff and would really appreicate some help understanding it all.

Thanks in advance,
Space"Noob"Monkey


ps/ didnt know if this should go in CPU area or MOBO area (its a bit of both).

it's up to the processor to enable the higher multi's. it's a hi/lo switch in the bridges. so yes, the xp2600 266 has a higher multi than the 333 model. if you had the 333 version with your board, you'd have to o/c the fsb (cpu host clock) to 166 to get the correct speed for the 2600. if your board has a 1/5 divider, (only the kt 333/400 and nforce2's have this) then you could run @ 166 fsb while keeping your pci and agp @ the spec 33/66mhz and thus run the 333 version of the chip without overclocking your fsb. then you'd overclock by going above 166.

this making any sense to ya?

Yeah, i think so.

So the CPU has the multiplier locked into it.

So this 2600+ 133 model would actually be running at 15.5 x 133 even though the mobo has a max setting of a x12.5 ratio.

If the ratio is locked into the CPU why do you need to set the jumpers on the mobo ?

Thanks

SM

i'm not familiar with your board, or it's jumpers, my board is for the most part jumperless but different manufacturers do things differently.

if you're mobo supports xp2600 it supports the higher multi's too. if you were to put this chip in, rather than 5-12.5 you'd see 13 and up.

ok thanks v much