how do you change the fsb from 800 to 533 in bios

[zb1979]

i have an asus p4s800 and wish to change the fsb from 800 to 533. how do i do this.

[schmosef]

http://forums.murc.ws/showthread.php?postid=487192#post487192

[zb1979]

sorry don't know much about ram freq and fsb. do you think the ram is the booting problem? i've looked on asus web site all i could find was it saying to do it in bios but not the settings to put it to. i've sent them an email too but no reply.

[schmosef]

I can't seem to get into their site right now. If I could, I'd download the pdf of your motherboard's manual and post images of the appropriate pages.

Yes it could be the ram. Or it could be something else. Is it posting but not booting or are you not even getting past the post? Do you have speakers hooked up? Is the post reporter saying anything?

[zb1979]

i have the manual but nothing seems to say anything about the settings to put in bios. i have actually just had a guess at the settings and the lowest it would let me change the speed? to was 200/33 and i changed the memory freq? from auto to 333mhz and it is booting up fine. it was stalling all over the place sometimes if i was in bios, sometimes halfway through xp loading, sometimes wouldn't even check video card, sometimes would get to the asus splash screen but wouldn't go any further (when it did this i couldn't even press del to go into bios or alt f2 to go to flash bios or tab to show post screen). do you think that being i've changed those settings and it's working fine now it would be the ram? so should i go and by some pc3200? also what do the settings mean that i changed it to?

cheers heaps you've been a big help so far. i hope you would be so kind to be a little more.

thanks

[schmosef]

I can't tell you anything more specifically until I take a look at the manual for your board.

I'm just not familiar with that particular model so I don't want to guess at features or optimal / appropriate settings.

It's not unusual for Asus' site to go down, especially on a weekend. It will be up soon and then I can take a look.

If you are considering the purchase of better RAM, check Asus' site when it comes up for their latest compatibility chart. Not all brands/models of memory are certified to work in dual channel mode. An ounce of prevention is worth a pound of cure. Check that the memory you are going to buy is certified to work with your board.

Further, the wholesale price difference between PC2100 and PC3200 is very very slight. If someone sold you the cpu, board, and RAM and told you that PC2100 runs at 400MHz and is the right choice for your config, I would be very wary of dealing with them in the future. First, I’d demand my money back and second, I’d never buy from them again.

[zb1979]

cheers heaps mate. after you can have a look that would be great!!

i bought the computer as made up and i have had this problem since not long after picking it up. i have taken it back to them a few times and they can never fix it.

i have been trying to fix it myself to try and be able to go back to them and go this is whats wrong my computer is at home because i'm not giving it to you again give me this..... or give me my money back now and you can come pick it up from my house later.

i'm sick of giving it to them for a week or so and it coming back the same each time and them saying we gave it a clean cause it was dusty and it booted first go for us, i take it home it boots first go (sometimes) but back to normal everytime after that. so i cleaned it myself the last time but they said the same (i cleanded it after i unpluged it all and then took it to them so it was obviously clean).

cheers heaps for your help.

[Sasq]

zb, (yes ignore the location) I am Australian.

If they don't fix it, you best bet is contact consumer affairs in your Homestate.

If you have any trouble, PM me with all the details, and I can give you more direct information.

It should work directly out from the shop, and them playing around is just c**p.

[zb1979]

i just rekon they got no idea. find out tomorrow though.

[ayoub_ibrahim]

could well be worth trying to raise Vdimm up a notch.
what ddr is it?

[zb1979]

what is that? there's 2 x 256 pc2100 ddr333 (i guess from what the first gentlman has said).

[UtwigMU]

OK here's a brief memory guide:
PC1600 = DDR 200 = 100 MHz memory bus double pumped
PC2100 = DDR 266 = 133x2
PC2700 = DDR 333 = 166x2
PC3200 = DDR 400 = 200x2

Pentium4 has quad pumped frontside bus, AthlonXP has double pumped frontside bus, with Athlon64, memory controller is integrated on CPU, so CPU can access it at native frequency.

For performance reasons, you want memory and CPU running synchronously and both as high as specs allow.

Pentium4:
P4 from 1.3 through about 2.2Ghz had a FSB of 100Mhz quad pumped, equalling 400MHz effective. Since at the time Intel was promoting Rambus RDRAM, PC800 RDRAM was mainly used with such P4's on i860 chipset boards.

There was also 845 chipset that allowed PC133 single data rate RAM, but such P4 systems were memory starved and performed significantly slower than RDRAM equivalents. In such case, memory ran at 133MHz and fron side bus ran at 100MHz quad pumped 400MHz effective.

Latter 845 chipset that supported double data rate RAM came out and also revised 860 boards that allowed for PC1066 RDRAM and 133MHz FSB

The boards FSB ran at 133MHz quad pumped, 533MHz effective and RAM ran at either 133MHz DDR PC2100 or more commonly 166MHz DDR PC2700 speeds.

533MHz FSB P4's were from about 2.4 to 3.06GHz. The 3.06 is highest performing 533MHz FSB part and only 533MHz part to have hyperthreading.

With 865 and 875 chipsets (the difference is that latter allows for more agressive memory settings, yielding better performance and is usually more common on higher end boards), intel introduced 800MHz FSB (200MHz quad pumped) P4's.

The boards commonly run PC3200 (400MHz) RAM and it's usually configured in dual channel (two sticks, each on it's own channel, theoretically doubling bandwidth).


Your board has SiS 648 chipset, that supports 800MHz FSB P4's and PC1600/PC2100/PC2700/PC3200 RAM.

Since right now asus site is down, there's no manual to be read, but from your post, your board has CPU/memory settings. If you have 800MHz FSB CPU, you should set CPU frequency to 200MHz, if you have 533MHz CPU you should set it to 133MHz.

As for memory: For PC2100 set memory to 133MHz, for PC2700 set it to 166, for PC3200 set it to 200MHz.

Depending on what kind of CPU and memory you actually have, CPU and memory being run out of spec might be the reason for your rebooting (you migt have gotten slower parts clocked out of specs).


Example: You have P4 2.8C (2.8GHz 800MHz FSB Northwood core Pentium 4 with 512kB of L2 cache) and a stick of PC2700 RAM.

In that case, 200/167 setting for CPU/memory is correct.

[UtwigMU]

What you need to do is to establish, what kind of CPU and memory you have in order to set BIOS correctly.

Check receipt if it states anything. Otherwise, memory should have marks on it, stating, what kind it is.

You can download CPU-Z (just google for "CPU-Z" to find out what kind of CPU you have.

Sisoft Sandra can also tell you about memory.

[schmosef]

That's a really good summary, UtwigMU.

@zb1979, If you are correct in your previous statement that you've got PC2100, then you need to set your memory freq. to 266MHz for ideal stability.

UtwigMU's second post about establishing exactly what hardware you've got is really important. Do that before you play in the bios again.

Ayoub_ibrahim's comment about raising Vdimm is to increase the voltage supplied to the memory. You only need to do this if you are using a pesky brand that's not certified or, in some cases, when you are trying to clock the CPU and releated buses higher than their rated speeds. You shouldn't have to do that for a brand new, pre-built computer.

Finally, dust isn't going to be the cause of your system stability problems, not on a brand new machine.

[zb1979]

to all that have helped me.

i thank you all, you have all helped me so much.

as i said above i was taking it back to the shop yesturday and getting them to swap the ram (oh the hassels, if i thought i had hassels bafore yesturday topped it off). they swapped the ram and set the bios back to defult and all is good. i had hassels because the receipt actually said 256mb pc2700 single sided. it not what i got though obviously. as what was in there was double sided 256mb pc2100. so this was a hassell. them trying to tell me i had taken out what they had put in and replaced it with that.

but anyways it all good now.

it took me a while to find a site with helpfull people about this but to you all i thank you greatly because i finally found a site that i will keep on reference and pop back in here and there to see if i can help others in the fashion that i have been helped (which i have already started doing).

once again thank you all.

p.s. if any of you have any tweaking tips here's a complete list of what i have

2600 mhz p4 800 fsb
asus p4s800
1 x 512mb pc3200 double sided
1 x 512mb pc3200 single sided (i think it's in the post)
geforce 64mb
seagate 7200rpm 80g
mator 3000le external 120g usb
lg liteon cd burner

actually the usb h/d i just bought second hand and it says it won't run. says something about code 10. do you guys know about this or should i look elsewhere?

thanks again guys