View Full Version : Will this CPU fit on my mobo?

03-08-2002, 03:34 AM
I have a Intel SE440BX-2 mobo. It supports CPU's upp to P3 850Mhz@100Mhz. But I wonder if I can buy a P3 866Mhz CPU and install it?
Is there any option to "downclock" it or something?
If I can get it to fit then I'll have a 2nd gameable computer :D


There's some info for my mobo.

I hope that it will work, I mean, why should it not?
The CPU is SLOT1 and the mobo is also SLOT1 (duuuh) :)

Thanx in adavance.

03-08-2002, 04:17 AM
Not at the 133MHz bus speed in all likelyhood. It'll probably run, just not at the 866MHz. More like 650 or something. The Intel BX board's don't have a real 133MHz setting, and few if any FSB options.

I'd say 99.9999999999999999999999999999999999999999% big, fat, hairy "NO"

03-08-2002, 08:33 AM
Yeah bein' an Intel board would probably not have the FSB settin' for 133MHz and even if it did floppy and IDE controllers plus various add on cards probably wouldn't like the overclocked bus rates. :smokin:

03-08-2002, 08:33 AM
Ok. But why? I mean, it's just 16Mhz difference. And the bus speed will decrease from 133 to 100Mhz. Won't it? But if the bus speed already is at 100Mhz, maybe it's a bigger chance for it to work?

03-08-2002, 08:39 AM
Yeah bein' an Intel board would probably not have the FSB settin' for 133MHz and even if it did floppy and IDE controllers plus various add on cards probably wouldn't like the overclocked bus rates.

But if the 866Mhz CPU is at 100Mhz then? I installed my P2 266Mhz MMX CPU on a celeron/P3 compatible mobo. It did run, but only at 133Mhz (Dunno about the bus speed thou). And since it was a Dell computer I could not attempt to "tweak" it to it's original speed.
Not so fun if this 866Mhz CPU only runs at 133Mhz... heh.
Maybe I should mail Intel and ask, but they will probably never answer me :(

03-08-2002, 10:28 AM
There is no 100MHz FSB 866 P3. It's a 6.5 multiplier and a 133MHz bus. Do the math with either bus: one is 650MHz the other 866. The 850 runs a 100MHz bus, hence 8.5x100=850

If the CPU is an EB or ends with the numbers 33 or 66, it's a 133MHz FSB chip. You can run it at 100MHz, but it won't run at full speed.

Chart below to illustrate.

5.5,6.0,6.5,7.0,7.5,8.0,8.5 x 100=550,600,650,700,750,800,850

5.0,5.5,6.0,6.5,7.0,7.5 x 133=667,733,800,866,933,1GHz

03-08-2002, 10:39 AM
And why pay for a CPU that your just goin' to underclock? Intel CPU's are fully multiplier locked so ya can't change that. :smokin:

03-08-2002, 06:05 PM
Yikes! :D
That was a hell of an answer Morgan :D Thanx.
Ok, I guess I have to buy a new cheap mobo for it then.
Maybe he'll throw away the CPU and the mobo for $90 or something.

Thanx dudes! :)

03-09-2002, 02:04 AM
Some places will cut you a deal on a mobo/CPU combo, not all, but it's not uncommon. Also, if possible, I advise taking local shops into account.

03-09-2002, 09:03 AM
I love my local stores, they provide answers and warranties that keep me coming back. Pricewatch is only a last stop effort.

-might be different with you

03-09-2002, 12:16 PM
I have two shops I'm particularly fond of myself here in town, and that's just from selection and support in general. I'm on pretty good terms with both shops, so most of the sales people know me well enough to show me some cool stuff they don't show other customers.

03-09-2002, 04:08 PM
Thats the kind of hookup everyone needs. Its just to hard to try and do everything we do as builders/overclockers/modders with just the distant help of the internet. With the exception of TT, which has aided me in numerous situations - whether i asked for it or not!

03-09-2002, 04:10 PM
Wait a sec. I posted that last reply , but it says fhgump did

03-09-2002, 04:13 PM
This says fhgump posted these last two when in fact i did.
whats wrong wit the forum. Im signing in as JediAgent!

Admin HELP!

03-09-2002, 07:57 PM
Hah :) Bothering or what to log in with another ID :)

Local stores you all say huh? Well, local stores here doesn't sell that old mobos or CPU's anymore...

The "slowest" stuff u can buy is 1Ghz.

03-09-2002, 09:01 PM
Be warned: Don't login at thje post reply page but do it at the front page till we can trace this prob. :smokin:

04-01-2002, 12:27 PM
You could try compgeeks.com. They have a lot of older stuff new and used. You may find what you need there. They dont list any slot 1 boards right now but keep checking. You'll see em there

04-11-2002, 12:31 AM
Back to the point, I think the 866 will just run at 6.5x100 instead. Those boards will run a Celeron II 800MHz Ok, so it should have no problem with the coppermine core.

Mr. C
04-11-2002, 12:25 PM
not much point in running an 866 at a mere 650 - better to get less processor I'd think, save a buck or 2.

04-12-2002, 08:57 PM
see if you can find a Celeron CuMine128 800,900 or 1000 - they're dirt cheap & run at a 100MHz FSB