overclocking dual p3's

[OCn00b]

Hello, I read somewhere that for best results for overclocking a P3 it's best to get a 100mhz FSB. First of all, is this true or should I just go ahead and get 133mhz? If 100mhz is better for overclocking, where can I find socket 370 P3's with 100mhz. The only ones I can find with 100mhz are slot 1's. Thanks for the help.

[Tecumseh]

Either should work just fine. The 100 MHz FSB CPUs are favored
because they give a finer adjustment i.e. the internal multiplier
is lower.

One place I know which still has the old P3s is here. (http://www.googlegear.com/)

[OCn00b]

Thanks for the help Tecumseh. So if I can run up to 140mhz fsb, then in theory I should be able to oc the 1ghz(100mhz fsb) to 1.4ghz right?

[Tecumseh]

Well, don't get too carried away. Check out the CPU database
on the front page. You will see that several guys have gone
over 1.4 GHz, but the average OC is less that 1.2 GHz.

Many things besides your CPU can hold you back. Even if your
RAM can handle the speed, other things come up. The video
card bites some people. A SCSI card bit me on the butt.

You got to take the system as a whole. The weakest link
in the OC chain will hold you back.

Starting will a dual system is probably not the easiest choice. :)

[OCn00b]

Well, technically this is my second OC but as far as it not being the easiest choice, i've always had to learn the hard way:) I understand that I probably won't be able to get 1.4 Ghz I was just saying theoretically based on the multiplier/fsb combination. If I'm right, on the 133 fsb it would be 7.5*133 so at 7.5*140 I would only get 1.05 Ghz but on the 100 fsb it would be 10*100 so at 10*140 I would get 1.4 Ghz. The motherboard I have is far from being the best but in theory 1.4 Ghz would be possible. I was just asking to make sure I understood the multiplier/fsb thing.

[OCn00b]

Also, any suggestions for what type of RAM I should use in it? Thanks.

[Tecumseh]

I have used Mushkin on some, but most of my RAM comes from
Crucial (http://www.crucial.com/).

It's very good and very inexpensive. Highly recommended.
Stick around for a while; I'm sure someone will come up
with another recommendation, but Crucial is probably the
most popular.

[OCn00b]

Cool, thanks for the info. I'm still having some trouble finding the 100 Mhz fsb on the 1 Ghz chips but I should have a little better luck when I can look at home instead of at work.

[OCn00b]

Ok, I was checking the Crucial site and was wondering, should the ram be unbuffered or registered or do I need to check the documentation for my motherboard? The unbuffered is CL-2 and the registered is CL-3.

[Tecumseh]

Yes, by all means check the motherboard documentation. There
is all sorts of good information hidden in there. :D

Crucial also lets you search by motherboard model and a few
other ways.

[OCn00b]

http://www.digit-life.com/articles/i815epacorp6a815epd/index.html is a link to the specs of my motherboard if it helps. It seems to perform relatively comparable to the Asus and SuperMicro plus it was a whole lot cheaper although it doesn't seem to be as overclockable which isn't my main goal with this comp. I'll try to find some more test and documentation throughout the day.

[Tecumseh]

Looks like a fine board. I'm sure you will be able to get some
good OC'ing out of it. Be sure to get PC133 RAM.

The only wierd thing about this board is fact that it has three
RAM slots and is maxed out at 512 MB. This is kind of limiting
for what could be used as a server.:( But for most purposes
512 MB is enough.

[OCn00b]

Well, actually mostly what this comp will be used for will be gaming, seti@home, programming, graphics editing and some audio/video editing which is why I chose a dual board. I'm not exactly thrilled about the 512 MB limit but for what I'll be doing that should be plenty of memory. After i get done building 1 other computer after this one, I may use this one as the server for my home network but I don't expect that I would need more than 512 MB even then. If I do, I'll just use the comp I have now. Also, I've decided instead of 2 1 Ghz cpu's I'm going to get 2 800 Mhz because I got a deal on a pair that I won't be able to beat. Because of that, I know have a potentially stupid question. If I were to be able to OC the 800's to 1 Ghz would they be faster than the 1 Ghz chips? Although I don't think I'll be able to get 1 Ghz out of that board since it doesn't seem to OC well with dual cpu's. I would have to get a 166 FSB which is 26 Mhz over what was stable in that test. Is there a chance watercooling or a peltier would help me get faster FSB speeds or is it more likely that the board just can't handle speeds that high? Finally, is there a way to increase my FSB without raising the PCI bus to unstable speeds? Ok, sorry, 1 last thing, in the bios for my memory timing(i think, i'll have to double check) my choices are 7/9 or 5/7 which one do you think would work out better for better OC speeds? Thanks for putting up with stupid questions and for helping me out.

[Tecumseh]

The 800's will be fine just as they are. I am typing this on
a dual 700 P3 and can do whatever I want. It is one of
the old dual BX boards that don't OC. Of course, I have an
entire farm of OC'd systems. :)

Assuming the cache size is the same an 800 OC'd to 1000
will have the same performance as a native 1000.

Having the PCI bus OC with the FSB is one of the big problems
with OC'ing. Some MB's have dividers that bring the PCI bus
closer to spec. OC'ing the PCI bus is not a problem with
some cards, but will prevent high speeds with others like
SCSI cards.

Before you build the system you should download and flash
the BIOS to the latest version.

As far as settings go...Experiment. That is half the fun. Read all
the docs and play with the system. If you get in over your head
on something you have come to the best forum on this planet.

There are tons of people here eager to help. Make the whole
project fun.:cool:

[Ebola]

1.4 ghz on .18 micron p3's isnt gonna happen. unless your lucky the .18's topped out at arround 1250 or so.

I have an abit vp6 with two 1000EB chips at 150 fsb (1125 mhz). runs nice. I have a gig of crucial pc133 cas 2 ram. 4x256.


now-a-days a dual amd would probably be cheaper.

[OCn00b]

Well, according to that test, I'll only be able to get the PCI bus to 35 mhz. Would that generally be considered safe? Also, will I be able to move my current HD into the new comp as is or will I need to format and have an empty drive at installation? Also, I've seen pc150 RAM for sale at different places. Does my board have to support pc150 or is that just for people with 133 mhz FSB who OC? How will I be able to flash the bios without having my HD already installed? I may just be ignorant but I thought a computer wouldn't even try to boot if a HD wasn't present.

[OCn00b]

Ebola, thanks for the info. I already figured I couldn't get 1.4 out of them, I was just saying according to the numbers, it was theoretically possible. In all reality, it they'll OC at all, i'll be happy. If this dual system works ok for me, I'll probably replace the amd i've got now with a dual amd board. I'm partial to amd anyway, I just got a really good deal on this board so I figured I would give intel a shot to see how it performs.

[mtnbikerjerry]

Originally posted by Ebola
1.4 ghz on .18 micron p3's isnt gonna happen. unless your lucky the .18's topped out at arround 1250 or so.

I have an abit vp6 with two 1000EB chips at 150 fsb (1125 mhz). runs nice. I have a gig of crucial pc133 cas 2 ram. 4x256.


now-a-days a dual amd would probably be cheaper.


Ebola,

I have the simliar set up as you with the same exact memory specs as you. I can't run my machine stable at 150FSB without my system crashing. I have my memory at CAS2, do I need to bring it down to CAS3 to prevent it from crashing? I have the Abit VP6. I know it sounds like a stupid question, but hey I might as well risk asking. The memory is PC133 CAS2 just like yours...it would run up to CAS3 150. Are you able to run your crucial memory at CAS2 at 150 FSB?

Just curious, and how were you able to achieve this?

Thank you,

J

[cack01]

Cas 3 would probably help your greatly. Will probably get you another 5 mhz out of the FSB. Also you can try lowering your timings.