CPU Clock settings in the bios???

[johningram]

Hi. I just purchased and installed a new motherboard/cpu combo and some new DDR RAM. I want to make sure everything is running as fast as possible. I dont actually want to overclock but i definitely dont want to UNDERclock either.
I bought a 2.4ghz Pentium-4 with 1 mb cache and a 533mhz front side bus and a matching ECS motherboard. The board supports 533 FSB speeds and actually supports them up to 800mhz. How do i know what bus speed im running at? In the bios i have a setting for spectrum spread or something like that and i dont know what that is other than it prevents em interference. Do i want that on or off? Also i have something called the CPU clock. I can adjust it from 133 to 250 or so. Its at 133 now but can i raise it higher? I thought it was my front side bus speed but it only goes to 250 so that cant be right? Help!

 

[cdogg]

John,

The frontside bus speeds you see for Intel CPU's is quad-pumped meaning a 533MHz FSB really runs at 133MHz x 4 (AMD's is double-pumped). The reason why it's rated so high is because it does have the potential to send 4 times as much data per clock cycle than a single-pumped bus.

So no, don't just start adjusting the FSB or you might accidently fry your CPU. For a Northwood P4, the FSB is supposed to be 533MHz (133MHz x 4). If that's what you have, then it's set correctly.


~cdogg
[tab]"All paid jobs absorb and degrade the mind";
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[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884

 

[johningram]

I actually understood that it is doubled and quadrupled but normally you can set the multiplier to 2 or 4 instead of it doing it behind the scenes right? Because i have no setting for how many times it is multiplied. It must just assume 4 times then i guess?

What about the spread spectrum thing and all the other bios settings. I know i want my AGP aperture to be the same size as what my video card is so if i have a 128mb card then it should be set to 128 in the bios right? what about all the other settings?

Thanks

 

[dakota81]

Well, this is where you need to through out the marketting terms in favor of the engineering specifications.

Quad pumped really means this:

First look at the Pentium !!! architecture, in the top models the datapath between the cpu and northbridge chipset ran at 133MHz and was 32bits wide. It was labelled 133fsb

Now in the P4 architecture, lets take a 533fsb model, the datapath between the cpu & chipset runs at 133MHz and is 128bits wide. Since 32x4=128, intel says their cpus are quad-pumped and run at 133x4=533fsb (although it is still a 133MHz clock). That 128bit datapath is fixed and cannot be altered, so setting a 133MHz clock in the bios correctly sets the cpu.


Spread spectrum is something that is supposed to help reduce interference with other electronics. It doesn't effect performance of the machine, but in some rare environments might caust stability problems. So it's a tradeoff between reducing interference & stability issues (though very uncommon).

AGP Aperature size is something different - it's the amount of system memory a program can use if the program exceeds the capacity of the video ram. Don't worry about this setting - if a game, for example, would ever need to use system memory for graphics, the performance hit would be enough to make you reduce the game settings (in effect having the game graphics fit in the video memory & not use system memory).

 

[EvilCabal]

Hello,

I was also wondering about the usefulness of spread spectrum, I found this site very interesting :

http://www.rojakpot.com/default.aspx?location=8&var1=0&var2=133

About the AGP aperture size, it does not need to match your video card memory size. It is the size of the memory buffer allocated for use when the graphic card runs out of memory. Since your card is 128 mb, this should not happen. So it's really up to you, you could even disable it until you face a need for it (witch, in my opinion, is very unlikely to happen).

I hope this helps.