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Fsb/Divider/overclock ??

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davefred99

Member
Joined
Mar 6, 2002
Location
Southern Californis
Ok here again asking another dumb question. Maybe someone can finally set me straight once and for all.

My set up can run from 100~123 fsb with a divider of 3 or 124~200fsb with a divider of 4. I understand that this is so the PCI & AGP bus can run closer to spec. I also can run my memory bus @ 100 or 133. When I oc @ less than 123mhz I have the option to run my memory @ host +33 or host speed.

My understandin of overall performance is that you want to get the highest possible CPU speed and FSB without pushing the PCI-AGP & Memory bus speeds to far out of spec. Lets say you can only oc CPU to 117fsb @ this speed you would be using a divider of 3 so the PCI would be 39mhz and the memory could run @ 117 +33 = 150. Would this system be as fast as a system that runs @ 150mhz fsb and host memory (150) using a divider of 4. The PCI bus would be slower (37.5mhz).

Also what are the reasonable limits for PCI speeds past 40mhz. I have heard that it is risky and not usualy recomended.

My current sys specs are in my signiture, Thanks for any advice or information.
 

funnyperson1

Senior Member
Joined
Jun 16, 2001
well to get pci speeds over 40 you need a very good LAN card (intel is recommended)..and very good hdds....also a very goood mobo.....

and no a system that runs at 150mhz fsb with PCI divider of four would be faster because the cpu would be much faster at that clock speed...
 
OP
D

davefred99

Member
Joined
Mar 6, 2002
Location
Southern Californis
Thanks for your speedy reply, I would like to clarify one thing though . Lets say you run a 1.0a @ 150 mhz if possible ? the CPU speed is 1500 and you run a 1.3a @ 117mhz = 1521mhz. The memory speeds would be the same if you configured it to host +33 = 150 The PCi & AGP would be running faster becaues of the 3 divider. THe benches I would think would be almost the same or am I missing something here.
 

Xaeryan

Member
Joined
Nov 12, 2001
I would have to predict that the first one's benches (1.0A @ 1.5) would be better. For a short explanation, you want to have a higher memory bus AND frontside bus more importantly than a higher PCI bus... If you could benchmark a system with the same FSB and Memory speeds, but different PCI/AGP speed, the higher PCI/AGP speed would give you insignificant gains.
Increasing FSB, and memory particularly, has a much greater performance gain.
And I'd advise against going above 40 MHz PCI bus speeds, too risky - data corruption may set in if your hard drive isn't up to it.
 

batboy

Senior Moment
Joined
Jan 12, 2001
Location
Kansas, USA
I'd have to mostly agree with X. Well, maybe a faster PCI bus is a little more than insignificant, but certainly higher FSB and faster memory is the best route for performance. I've never had a system yet that was stable with the PCI bus that was higher than 40 MHz. Some folks claim to be stable above 40 on the PCI bus, but those are the exception, not the rule.