will a 800Mhz FSB cpu work on a 533

will a 800Mhz FSB cpu work on a 533 MoBo

Hey all,
Well I didnt think I would have time today to install my new 2.8c but I did.Anyways I have a Abit Max2 version2 MoBo 533Mhz FSB and my cpu is 800Mhz so when I install it I thought it would still work but Im thinking NOT.I installed it and when I turn on the power it just shuts right back off so Im thinking it must be the FSB speed diffrence.Can someone tell me if a 800Mhz FSB cpu will work on a 533Mhz MoBo?
Thanks,Shark

It will work but just run at 533MHz Defalt Most likely you can OC the board well past 800MHz

Hmm,I wonder why it just shuts right off when I turn it on .I reset the BIOs so I really dont know what else to do...HELP
Shark

I remember doing a search for this, as I have a IT7 as well.

The IT7's max FSB is 250Mhz, so you'll just have to run the FSB past 200Mhz to overclock 800FSB P4s. Like Mr. $T$ said, the P4 will work at lower FSBs as well, but it will be running underclocked.

I've never ran my IT7's northbridge as fast as 200Mhz, so I can't confirm if it is possible or not. Highest I've got was around 180Mhz. But that's probably limited by the 2.26b rather than the motherboard. Although I can't confirm the 845 chipset being able to run past 200Mhz, it certainly might be possible.

You might also consider getting a refurbished Abit IS7 for cheap.

edit:

just saw this:

SharkDiver said:

Hmm,I wonder why it just shuts right off when I turn it on .I reset the BIOs so I really dont know what else to do...HELP
Shark

Click to expand...

hmm... maybe they don't work in the IT7 then? only thing I can think of besides something not being connected properly is a bios update...

so everything is connected like it was before?

I wonder if its a DOA cpu?I started my cpu to clock it down before I installed the new 2.8 from my old 2.6 and it started and ran fine.I dont have another 478 pin computer around here to try the chip on another MoBo so I have no way to check to see if its working fine.Im going to recheck all my connections again but I think its the cpu or the BIOs shutting it down.I turn it on and everything comes on for about 1 sec. then off
.
Ill check back here in a few.
Thanks ,Shark

bios update...

Click to expand...

That it did not do to this MoBo inawhile.right now I cant even think of what bios I have on it....I better go check abits site again...

Did you update the BIOS to the newer one that supports the 800 bus? It's generally not the best idea to use a "C" processor in a mobo that's not designed for them.

No I didnt so that must be the problem..I havent updated BIOs in a long time so can someone give me the program that does it?

Heres a link to get you started
http://www.abit-usa.com/downloads/bios/p4.php

Thanks for the help you guys And thanks for the link,I will let you know if it works after I put back my old cpu in and do the bios and then change back to the new Looks like a long night .
Shark

Well I figured out why my rig kept shutting off right away,my screws for the cpu sink are shorting out something so when I dont put the screws in it starts fine .I have no idea why this is happening because it is the same one Ive been using for awhile.
Anyways,I updated my bios to the newest version (E6) anyways but now my Bios will not hold my settings.I set it up for 2.79 which is 133X21 and set my DDR timings to 2.5-6-3-3 when I normaly run it at 2.5.2.2 and my Ram volts are set to 2.5v but when I save it all and it restarts it all goes back too 1.8Ghz .And I also keep getting that stupid (Cpu is un-workable) error from time to time today .Im stumped once again.
any help would be great again guys
Thanks Shark

ps.I was going to try the halt on no errors but I cant find that in my bios,weird.

Well I found out some of my problem and that is,My mulitiplier is 14 and I thought it was 21 so that is why it kept going to 1.8 .But I cant get it to boot to windows if I set the FSB past 196=2.75Ghz prob. because of the ram even tho I had this RAM stable @ 412Mhz before.I guess I will just have to wait till I get my new MoBo .
Shark

If it really is the RAM, then you could try lowering the CPU:RAM divider to 5:4 or 3:2 to solve the problem

However, I suspect that it might be the chipset that's limiting you, as the 845 was not orginall designed for 100 and 133FSB P4s.

I wish I could change the ram to 5:4 or 3:2 but this board dont have those settings .I have 1:1 or 4:5 which kinda suxs in this case.

Yeah, only the i865 and i875 mobos allow the use of 5:4 and 3:2 ratios.

Doh! just realised... me=dumbass. thanks batboy!

That's true. No 5:4 or 3:2 on the IT7.

What RAM timings did you use? Try slower timings on the RAM, with more voltage. If it still does not work, then it's most probably the motherboard.

Well right now Im setting it to 1:1 and high (533Mhz) because it will not boot at 4:5.I keep the volts at 2.8 because thats the highest it will go.It really suxs that I cant even run thischip at its rate of 2.8,I can only get it to boot at 2.75 so I guess I wont be overclocking untill my new board gets here sometime.
Shark

sorry that I was not clear enough about this in my last post...

I didn't mean the ratio, I mean under "advanced chipset features", what did you set for all the DRAM timings, CAS, precharge, RAS to CAS, RAS prechard.

can you use higher numbers for those 4 settings? that will slow the RAM down, but might allow you to run a higher FSB, if it's your RAM that's holding your back.

i have the same question only on an iwill p4ht (533fsb/845pe) mb ~~~ wanted to try hyper threading and seems the only cpu with ht is the 3.06ghz/533fsb that is supported on this mb ~~~ will a "c" 800fsb chip & using ddr400 work on this board and support hyper threading?? thanks

I was setting my timings to 2.5.2.2 but Now im tring 2.5.3.3 and it dont seem to help,So I put it back to 2.5.2.2..I may try upping the volts on my cpu to 1.6v and see if it will boot and run.I wont have time to mess with ti untill I get home from work tonight tho.
Right now I have it pretty stable at 2.73 with the FSB set to 533Mhz and a 1:1 ratio with like I said the ram timings at 2.5.2.2.
If this is the best I can do for now that is ok because I think I may just order the Max3 this week .
Shark

Dude I have the solution for you!

Its a known fact that the 845PE chipset has problems getting anywhere passed 196fsb UNLESS you enable the 1/6 divider, then you should be able to go as far as either the chipset will allow before it phyically maxs out, as far as the agp/pci can handle, as highas the cpu can take, and lastly as high as your memory can go.
Now you ask where is this 1/6 divder found in the Abit max2 v2 bios? Its not, but the board DOES support it, all you need to do is download the modded bios by Phantom Punisher http://www.geocities.com/troyboy162/ flash it. I been using his modded D6R with 3.01 bios for about 6 months now, it rules! Also with this modded bios you have high memory voltage options.

I worked out that with your ram stable at 412mhz that works out to 206fsb and equals 2884mhz. If you can crank out your memory voltage you should be able to get alot higher. Im running 1gb of xms3500 and get [email protected] ok timings 2-3-2-7 totally stable can even go as high as 440mhz for test purposes. With a 2x256mb or a just a single stick 512mb of ram you should expect better results than me.
If you could max out the boards fsb to 250 then you would get it to 3500mhz, but I doubt your get to that since there could be to many limiting factors present. More realistly you could possibly reach 230fsb and get 3220mhz with agp/pci at 76/38mhz with if you can get you memory that could take 460mhz, just pump high voltage into and see. Playing it down more you could easily get to somewhere near that previous fsb i just mentioned without to much trouble.

Your board 845PE chipset supports HT so that not an issue with the 2.8c you have. They only say that about the 3.06 since its the only offical supported 533 HT cpu ever made for that particular board. And example for an 800 HT cpu running on a 845 chipset is the Abit BH7. No worries there.

Go do it dude!, flash with the modded D6 and set the 1/6 divider, remmember to up your memory voltage and relax those timings to go for big fsb.
I can't wait to see how high you get your fsb with your IT7 max2 v2 and 2.8c cpu.