Sign in with
Sign up | Sign in
Your question

AGP/PCI Clock Correlation

Last response: in Graphics & Displays
Share
April 9, 2004 1:51:34 PM

Archived from groups: alt.comp.periphs.videocards.nvidia (More info?)

In a previous post, PRIVATE1964 disputed that the AGP clock(when
adjusted) does not affect the PCI clock speed, which as many have
proven is false.


If you agree with the fact that the PCI clock speed is raised in a
direct affect to the AGP clock, reply as such.



If someone OTHER THAN PRIVATE can dispute that this is not the case,
please do so.


I'd like to be proven wrong, as long as it's done by someone coherrent.
April 9, 2004 3:48:20 PM

Archived from groups: alt.comp.periphs.videocards.nvidia (More info?)

Isn't it a case where both statements could be true depending on the
motherboard / chipset and implementation by the manufacturer if the PCI/AGP
speed is synchronous with the FSB or not and then if the board has a PCI
divider. And if that divider could influence the AGP speed as well - since
that works from the initial speed of the FSB, but.....

I have not worked with a system though where when a PCI speed is not locked
at 33mhz but controlled through a divider and adjusting that divider also
changes the AGP speed. But I have worked on a system where the FSB would
increase the PCI speed and so used a divider setting to reduce it back close
to 33mhz but has left the AGP running above the 66mhz it is specified to run
at - usually, but not always, without problem as the most sensitive of the
two was the PCI bus running out of spec and in particular the IDE
controller.

As a side note I have found that adjusting an AGP bus speed from 66mhz all
the way to 99mhz has no beneficial effect as I once thought it would.



--
Regards

Morgan

No more noisy hard drive for me...

www.flyinglizard.freeserve.co.uk
Anonymous
April 9, 2004 4:46:00 PM

Archived from groups: alt.comp.periphs.videocards.nvidia (More info?)

I am an A+ Certified Technician and have been involved with computers for
over 20 years and I have never seen an AGP bus speed effect the PCI speed.

The PCI bus speed is determined by a divider applied to the fsb(CLK), the AGP
speed is also determined by a divider off the fsb(CLK) or can be locked to
66mhz for motherboards that don't offer the option in the bios.

If you run the fsb out of spec and you don't have the proper divider for the
PCI bus, then the PCI bus speed will be overclocked, but that doesn't effect
what the AGP bus is doing. The fsb(CLK) effects the AGP speed, but not with the
Nforce chipset.
The main point is if you have an option in your bios that can increase the AGP
bus speed, it does not increase the PCI speed also, but the only way to run the
AGP out of spec is to overclock the fsb. Even that is not 100% true anymore
because the Nforce chipset does let you overclock the AGP bus speed even if the
fsb is running within spec.


You have a main clock signal that the PCI and AGP bus speeds work off of with
dividers. PCI does not effect AGP and AGP does not effect PCI. The main clock
and dividers determine the speed of each one.

This topic is ridiculous. The same person that posted this topic claimed there
is no such thing as an AGP bus.

http://www.nvidia.com/object/LO_20010614_6672.html
Related resources
Can't find your answer ? Ask !
Anonymous
April 9, 2004 4:53:52 PM

Archived from groups: alt.comp.periphs.videocards.nvidia (More info?)

>As a side note I have found that adjusting an AGP bus speed from 66mhz all
>the way to 99mhz has no beneficial effect as I once thought it would.
>

It does give you something in benchmark tests, but so little it probably
doesn't give you anything extra in actual 3D applications like games.

Running 3Dmark2001at 99Mhz gives me around 200 extra points over 66Mhz. The
gain is most likely not worth the risk of running the video card out of spec.
Anonymous
April 9, 2004 10:28:44 PM

Archived from groups: alt.comp.periphs.videocards.nvidia (More info?)

"teqguy" <teqguy@techie.com> wrote in message
news:Gmudc.3414$F9.1517@nwrddc01.gnilink.net...
> In a previous post, PRIVATE1964 disputed that the AGP clock(when
> adjusted) does not affect the PCI clock speed, which as many have
> proven is false.
>
>
> If you agree with the fact that the PCI clock speed is raised in a
> direct affect to the AGP clock, reply as such.

In my experience (more than 20 years working with computers), with an HP
S.T.A.R. certification, Microsoft MSCE 3.51, 4.0 +I, 2000 +I ,Compaq ASE,
and a Cisco Design Specialist designation... In the real world of business,
this isnt a matter worth contemplating.

However, as an enthusiast , hobbist, gamer, overclocker, whatever... its
academic.

All things begin with the FSB. Branched busses are based on factors of the
FSB. Branches are determined by dividers which are set in stone. You cannot
independently alter one bus without altering another. AGP will always be 2x
of the PCI. the PCI will always be based at1/3, 1/4, 1/5, or 1/6 of the FSB.
Period. And CPU and Memory Bus' are always the same.

Some board makers will allow you to increase the CPU bus, while locking the
PCI and AGP at the standard dividers for a given bus speed. But this does
not mean that you can alter only one bus frequency in complete isolation.
There is always a tether to another bus.

>
>
> If someone OTHER THAN PRIVATE can dispute that this is not the case,
> please do so.
>
>
> I'd like to be proven wrong, as long as it's done by someone coherrent.

i'm not sure which side of your argument my comments support... all i can
tell you is that its accurate and truthful. Do with it what you will.
Anonymous
April 9, 2004 10:58:03 PM

Archived from groups: alt.comp.periphs.videocards.nvidia (More info?)

"nut cracker" <nutcracker@internationalhacker.org> wrote in message
news:JJmdnbF80a__rOrdRVn-uA@speakeasy.net...
>
> "teqguy" <teqguy@techie.com> wrote in message
> news:Gmudc.3414$F9.1517@nwrddc01.gnilink.net...
> > In a previous post, PRIVATE1964 disputed that the AGP clock(when
> > adjusted) does not affect the PCI clock speed, which as many have
> > proven is false.
> >
> >
> > If you agree with the fact that the PCI clock speed is raised in a
> > direct affect to the AGP clock, reply as such.
>
> In my experience (more than 20 years working with computers), with an HP
> S.T.A.R. certification, Microsoft MSCE 3.51, 4.0 +I, 2000 +I ,Compaq ASE,
> and a Cisco Design Specialist designation... In the real world of
business,
> this isnt a matter worth contemplating.
>
> However, as an enthusiast , hobbist, gamer, overclocker, whatever... its
> academic.
>
> All things begin with the FSB. Branched busses are based on factors of the
> FSB. Branches are determined by dividers which are set in stone. You
cannot
> independently alter one bus without altering another. AGP will always be
2x
> of the PCI. the PCI will always be based at1/3, 1/4, 1/5, or 1/6 of the
FSB.
> Period. And CPU and Memory Bus' are always the same.

Above statement applies to real world of technology. You wont find a HPaq,
Dell or IBM server that will allow you to monkey with that. On the
otherhand... for consumers:

There are technical deviations from this, like VIA Appolo Pro133A chipsets
allowing you to run PC133 memory at 133Mhz while you have a 100Mhz FSB
processor.... My KT333 chipset on my Abit KX7 allows me to have a 200/233
CHIP with 333 DDR.

My KT400 chipset allows me to run my memory out of sync with the CPU bus,
but only at speeds faster than the CPU bus.

But DDR and RAMBUS are muliples of the FSB on the board. Most current CPU's
"pump" the FSB to give you the internal clock of the CPU. So, an 800Mhz FSB
P4 is really a Quad 200Mhz FSB. AMD's are doubled (thanks to the Alpha EV
bus architecture, 333Mhz Bartons are (2x 133 FSB).. and on and on.

>
> Some board makers will allow you to increase the CPU bus, while locking
the
> PCI and AGP at the standard dividers for a given bus speed. But this does
> not mean that you can alter only one bus frequency in complete isolation.
> There is always a tether to another bus.
>
> >
> >
> > If someone OTHER THAN PRIVATE can dispute that this is not the case,
> > please do so.
> >
> >
> > I'd like to be proven wrong, as long as it's done by someone coherrent.
>
> i'm not sure which side of your argument my comments support... all i can
> tell you is that its accurate and truthful. Do with it what you will.
>
>
Anonymous
April 10, 2004 4:25:42 AM

Archived from groups: alt.comp.periphs.videocards.nvidia (More info?)

>But this does
>not mean that you can alter only one bus frequency in complete isolation.

That's not true. I can set the AGP bus speed on my NF7-S to anything I want up
to 99Mhz and it does not effect the PCI bus one bit.
Anonymous
April 10, 2004 4:58:45 AM

Archived from groups: alt.comp.periphs.videocards.nvidia (More info?)

>You cannot
> independently alter one bus without >altering another.

That's not true, if that was the case I would not be able to set the AGP bus
speed in my bios on my NF7-S to anything I want up to 99Mhz which I can do and
have done.
It did not effect the PCI bus speed at all.

That is a fact!

If it also raised the PCI bus do you honestly think my hard drives would run OK
at 50Mhz because that would be the speed the PCI bus would be running at
according to you? Unless it was locked at 33Mhz which it is.

If you increase the fsb, the PCI bus and AGP bus speeds will also increase.
Unless the PCI bus uses a divider to limit the speed to 33mhz. The same goes
for the AGP bus, but it would be limited by a divider.
If I change the divider for the AGP bus so it runs faster, that does not effect
the divider for the PCI bus. The PCI bus will alway run at the speed of it's
own divider.

Why would the PCI bus be effected by what the AGP bus speed is doing?


>> All things begin with the FSB. Branched busses are based on factors of the
>> FSB. Branches are determined by dividers which are set in stone.

That it correct, but changing the divider of one does not change the divider of
the other one.

I'm done with this. I'm not gonna argue about a simple fact, and I do mean
simple fact about computer buses.
So you can all go on and discuss it to death, I just don't care.
The fact remains plain as day, increasing the AGP bus speed does not effect the
PCI bus speed like the person who posted this topic has claimed.
If you think the PCI bus is effected by raising the AGP bus speed then maybe
you should go back to school
and learn some more.

Case Closed!
Anonymous
April 10, 2004 5:03:38 AM

Archived from groups: alt.comp.periphs.videocards.nvidia (More info?)

>>You cannot
>> independently alter one bus without >

Here's some more proof.

http://www.rme-audio.com/english/techinfo/nforce2_tweak...

Scroll down until you see this

"though the AGP bus speed can be manually configured independently of the
locked PCI bus speed)."


I rest my case morons!
Anonymous
April 10, 2004 5:03:39 AM

Archived from groups: alt.comp.periphs.videocards.nvidia (More info?)

so much for being done and case closed, eh?

your example is taken, but that is not the standard.

"PRIVATE1964" <private1964@aol.com> wrote in message
news:20040409210338.00534.00000106@mb-m29.aol.com...
> >>You cannot
> >> independently alter one bus without >
>
> Here's some more proof.
>
> http://www.rme-audio.com/english/techinfo/nforce2_tweak...
>
> Scroll down until you see this
>
> "though the AGP bus speed can be manually configured independently of the
> locked PCI bus speed)."
>
>
> I rest my case morons!
Anonymous
April 10, 2004 6:48:11 AM

Archived from groups: alt.comp.periphs.videocards.nvidia (More info?)

>so much for being done and case closed, eh?
>
>your example is taken, but that is not the standard.

No one mentioned a standard at the start of this topic so why does that matter
now? It pisses me off that someone posts a topic and the minute someone proves
it someone comes along and tries to change the topic into something else like
they are wrong.

The topic was the relation of AGP speed to PCI speed thats it. Nothing about
the standard was ever mentioned.
Don't change the topic the minute proof is posted which is done quite a bit.

Besides it has nothing to do with a standard anyway.
I posted that link to prove that the AGP bus could be changed independently
from the PCI bus because someone posted it wasn't possible.

Also If you have an option to change the AGP bus speed in your bios and you
increase it. That does not effect the PCI bus at all on any motherboard.

Notice I said any motherboard!

That is a fact and If you don't believe that fact then you don't know very much
about computers !
Anonymous
April 10, 2004 6:48:12 AM

Archived from groups: alt.comp.periphs.videocards.nvidia (More info?)

"PRIVATE1964" <private1964@aol.com> wrote in message
news:20040409224811.03582.00000101@mb-m25.aol.com...
> >so much for being done and case closed, eh?
> >
> >your example is taken, but that is not the standard.
>
> No one mentioned a standard at the start of this topic so why does that
matter
> now? It pisses me off that someone posts a topic and the minute someone
proves
> it someone comes along and tries to change the topic into something else
like
> they are wrong.

dude, relax. you are getting all worked up over what....

>
> The topic was the relation of AGP speed to PCI speed thats it. Nothing
about
> the standard was ever mentioned.
> Don't change the topic the minute proof is posted which is done quite a
bit.

proof has to be irrefutable under all circumstances. You have only shown
exceptions to generally accepted standards.

>
> Besides it has nothing to do with a standard anyway.
> I posted that link to prove that the AGP bus could be changed
independently
> from the PCI bus because someone posted it wasn't possible.

>
> Also If you have an option to change the AGP bus speed in your bios and
you
> increase it. That does not effect the PCI bus at all on any motherboard.
>
> Notice I said any motherboard!

I can up the AGP bus on my gigabyte 7VAX-A, but it also up's the PCI at the
same time. I cant do it seperately. So there, you are wrong. NOT, as you
say, " on any motherboard ". You have to watch it when using absolutes, as
its way to easy to make a complete ass of yourself. but you wouldnt
understand that, would you?

>
> That is a fact and If you don't believe that fact then you don't know very
much
> about computers !
>

wow. you really showed me. now i see how ignorant i am. thank you so much
for helping me see that.
Anonymous
April 10, 2004 8:30:31 AM

Archived from groups: alt.comp.periphs.videocards.nvidia (More info?)

>dude, relax. you are getting all worked up over what....

No I will not relax. I was harrased for helping someone who asked a simple
question and I'm sick of it. I was 100% correct with my answer.


>proof has to be irrefutable under all circumstances. You have only shown
>exceptions to generally accepted standards

Why should I care about all circumstances? They have nothing to do with how
this topic came about. There you go changing it into something else.


> can up the AGP bus on my gigabyte 7VAX-A, but it also up's the PCI at the
>same time. I cant do it seperately. So there, you are wrong. NOT, as you
>say, " on any motherboard ". You have to watch it when using absolutes,

That's bullshit! Unless you are raising the fsb to increase the AGP bus speed
and you do not have the proper divider for the PCI bus to keep it at 33mhz.

You also took my words out of context.

I said "If you have the option" to increase the AGP bus speed in the bios then
it does not effect the PCI bus at all on any motherboard.

>way to easy to make a complete ass of yourself.

The only ass here is you pal.


>wow. you really showed me. now i see how ignorant i am. thank you so much
>for helping me see that.

I don't have to prove your ignorance, your doing well enough on your own.
Anonymous
April 10, 2004 9:57:11 PM

Archived from groups: alt.comp.periphs.videocards.nvidia (More info?)

"PRIVATE1964" <private1964@aol.com> wrote in message
news:20040410003031.10047.00000173@mb-m17.aol.com...
> >dude, relax. you are getting all worked up over what....
>
> No I will not relax. I was harrased for helping someone who asked a simple
> question and I'm sick of it. I was 100% correct with my answer.

there you go again with the absolutes... tisk tisk

>
>
> >proof has to be irrefutable under all circumstances. You have only shown
> >exceptions to generally accepted standards
>
> Why should I care about all circumstances? They have nothing to do with
how
> this topic came about. There you go changing it into something else.

to be 100% correct, you have to be right in all circumstances. duh...

>
>
> > can up the AGP bus on my gigabyte 7VAX-A, but it also up's the PCI at
the
> >same time. I cant do it seperately. So there, you are wrong. NOT, as you
> >say, " on any motherboard ". You have to watch it when using absolutes,
>
> That's bullshit! Unless you are raising the fsb to increase the AGP bus
speed
> and you do not have the proper divider for the PCI bus to keep it at
33mhz.

see, you are contradicting yourself. Not all boards (in fact, most) allow
you to adjust the bus's independently of eachother.

>
> You also took my words out of context.

that may be. if that is the case it is solely due to the fact that you did
such a terrible job of expressing yourself.
>
> I said "If you have the option" to increase the AGP bus speed in the bios
then
> it does not effect the PCI bus at all on any motherboard.

>
> >way to easy to make a complete ass of yourself.
>
> The only ass here is you pal.
>
>
> >wow. you really showed me. now i see how ignorant i am. thank you so much
> >for helping me see that.
>
> I don't have to prove your ignorance, your doing well enough on your own.
>

stop trying to get the last word in. it wont happen.
April 11, 2004 11:56:51 PM

Archived from groups: alt.comp.periphs.videocards.nvidia (More info?)

Jeez I can't even work out who is claiming what - but many mobo bios's now
do allow the AGP and PCI bus speeds to be set independantly (by changing the
divider for the PCI bus) and many overclockers demand this facility on their
mobo's - just check out the forum threads at
http://www.overclockers.co.uk

"PRIVATE1964" <private1964@aol.com> wrote in message
news:20040409202542.23150.00000092@mb-m22.aol.com...
> >But this does
> >not mean that you can alter only one bus frequency in complete isolation.
>
> That's not true. I can set the AGP bus speed on my NF7-S to anything I
want up
> to 99Mhz and it does not effect the PCI bus one bit.
Anonymous
April 11, 2004 11:56:52 PM

Archived from groups: alt.comp.periphs.videocards.nvidia (More info?)

>Jeez I can't even work out who is claiming what - but many mobo bios's now
>do allow the AGP and PCI bus speeds to be set independantly (by changing the
>divider for the PCI bus) and many overclockers demand this facility on their
>mobo's - just check out the forum threads at
>http://www.overclockers.co.uk
>

Thank you.

Some older motherboards as well such as the BH6, which is everything I have
claimed and nothing more then that.

I have also claimed that if you have an option in the bios to increase the AGP
speed, it will not effect the PCI speed on any motherboard.

Nutcracker read below this line because we both know how much trouble you have
comprehending the english language compared to everyone else. Right dickhead?

By posting any motherboard, I mean any motherboard that has the "option to
change the AGP speed in it's bios".
Anonymous
April 11, 2004 11:56:53 PM

Archived from groups: alt.comp.periphs.videocards.nvidia (More info?)

"PRIVATE1964" <private1964@aol.com> wrote in message
news:20040411152754.01314.00000188@mb-m14.aol.com...
> >Jeez I can't even work out who is claiming what - but many mobo bios's
now
> >do allow the AGP and PCI bus speeds to be set independantly (by changing
the
> >divider for the PCI bus) and many overclockers demand this facility on
their
> >mobo's - just check out the forum threads at
> >http://www.overclockers.co.uk
> >
>
> Thank you.
>
> Some older motherboards as well such as the BH6, which is everything I
have
> claimed and nothing more then that.
>
> I have also claimed that if you have an option in the bios to increase the
AGP
> speed, it will not effect the PCI speed on any motherboard.

I can up the AGP on my gigabyte, but it also ups the PCI... Its your
thickheaded use of absolutes that makes you look stupid.

> Nutcracker read below this line because we both know how much trouble you
have
> comprehending the english language compared to everyone else. Right
dickhead?

yawn...

> By posting any motherboard, I mean any motherboard that has the "option to
> change the AGP speed in it's bios".
>
!