fsb speed - why does it matter?

James Hanley wrote:
"Adam Webb" wrote in message
...
it seems to me that nobody needs a high fsb. since they could just
push the multiplier really high.

you cant push the multiplier high because its locked on most modern
CPU's

nobody on an overclocking forum should be saying
"oh no, the multiplier is locked, what am I going to do"
Just like no technician is going to say, oh no, the file is 'hidden'
what am I going to do.

Better analogy: the technician saying "oh no, someone has wiped the disk
then turned it into slag in a blast furnace, what am I going to do?". Given
that people have spent close to 6 years trying to unlock Intel CPUs (no
success) and about 1 year trying to unlock locked AMD chips (no success), I
doubt there's going to be much progress on either front. The general view is
that both companies are using fuses inside the die, which can't be altered
once set.

also higher FSB = higher bandwidth = higher performance.

yeah, if it's greater width. i'm talking about speed only though.

Umm, say what? It's obvious that more throughput = more performance, and
throughput = bus width * bus speed, so increasing the bus speed (FSB)
obviously increases performance. Or do you think a Athlon running sync with
PC66 RAM (66MHz FSB, SDR, 64 bits wide) would perform just as well as the
identical CPU running sync with PC3200 RAM (200MHz FSB, DDR, 64 bits wide)?

--
Michael Brown
www.emboss.co.nz : OOS/RSI software and more
Add michael@ to emboss.co.nz - My inbox is always open

well, AMD can be unlocked. Maybe intel can. They are not really
'locked' they are 'locked' for people that don't know how to unlock
them.
OK Then, Tell us how to unlock the multiplier on the newer locked
CPUs.

Just as windows files are 'hidden', it's just a gimmick to make it
'harder'.
Apples and Oranges there.


LOL
I fail to see the joke

----------------------------------------------------------------------

You should start drinking prune juice and KY jelly cocktails right now,
that will make things a lot smoother.
-Felatio Love

Obviously I see the benefit of more cycles. What do you think I meant
when I said "push the multiplier really high". That increases the
cycles per second.

CPU cycles = yes, memory frequency = no. Only raising the FSB
increases the speed at which the CPU can access the memory.
----------------------------------------------------------------------

You should start drinking prune juice and KY jelly cocktails right now,
that will make things a lot smoother.
-Felatio Love

James Hanley wrote:
David Maynard wrote in message ...

James Hanley wrote:


it seems to me that nobody needs a high fsb. since they could just
push the multiplier really high.

I can see the greatness of ddr since the same speed processor can
read/write twice as much per cycle. (i assume that the cpu has to be
ddr to receive or write double)

How is it you can see the benefit to 'read/write twice as much per cycle'
yet not see any benefit to more of the cycles?

The CPU communicates to everything through the FSB, and that includes the
memory, so the speed of it directly affects how fast the processor can
communicate. And since the vast majority of that communication is fetching
instructions from memory, it affects how fast it can process them.


The FSB is not THE ONLY THING that affects the speed. The
Multiplier*FSB create the speed. The Processor multiplies the FSB,

I didn't say a thing about the CPU speed. I was talking about the FSB: the
'point' of the discussion. And, as I said, the only means the CPU has to
COMMUNICATE to anything, including the memory, is through the FSB.

Just how fast do you think it can get instructions to execute if you turned
the FSB down to 1 Hz, eh?

It doesn't make any difference how fast the CPU can execute instructions if
you can't feed it the instructions to execute.

and the RAM multiplies the FSB.

No. It doesn't 'multiply' the FSB. It operates at the memory bus clock rate.

I am saying that the multiplier can
be increased, so low FSB speed doesn't matter.

You missed the entire point, and are incorrect.

James Hanley wrote:

David Maynard wrote in message ...

James Hanley wrote:


it seems to me that nobody needs a high fsb. since they could just
push the multiplier really high.

I can see the greatness of ddr since the same speed processor can
read/write twice as much per cycle. (i assume that the cpu has to be
ddr to receive or write double)

How is it you can see the benefit to 'read/write twice as much per cycle'
yet not see any benefit to more of the cycles?


Obviously I see the benefit of more cycles. What do you think I meant
when I said "push the multiplier really high". That increases the
cycles per second.

No, increasing the multiplier does NOT increase the FSB cycles.

GTD wrote in message . ..
Obviously I see the benefit of more cycles. What do you think I meant
when I said "push the multiplier really high". That increases the
cycles per second.

CPU cycles = yes, memory frequency = no. Only raising the FSB
increases the speed at which the CPU can access the memory.
----------------------------------------------------------------------

memory frequency can be increased to a multiple of the FSB even before
DDR is 'applied'. I have an option in my BIOS to set my DDR-SDRAM
frequency, I can set my FSB to 100 and my SDRAM to 266 (effective).
So my actual RAM speed is operating at a frequency of 133 internally,
which is FSB*(5/4). I don't know if it uses its own multiplier to do
that, I think it probably does.
So both RAM and CPU can operate at a frequency that is a multiple of
the FSB.
So memory frequency can be increased without increasing the FSB.

However, against me, I will say that it just occurred to me that the
speed at which the CPU and RAM interfaces with the FSB is still going
to be the speed of the FSB, regardless of how high their internals
speeds are. Thus if one were to weigh doubling the FSB against
doubling the Multiplier(timesing the current value of the multiplier
by 2), they would find that doubling the FSB makes for a faster
computer, since it would have doubled not just both the internal
frequency of the CPU and RAM - thus their bandwidth, but the speed
and thus bandwidth of the bus.

(i'm assuming bandwidth=throughput, but I cannot check at this moment,
since I'm leaving in a minute, so I have to click Send now!!

Thanks for your response.

"Michael Brown" wrote in message ...
James Hanley wrote:
"Adam Webb" wrote in message
...
it seems to me that nobody needs a high fsb. since they could just
push the multiplier really high.

you cant push the multiplier high because its locked on most modern
CPU's

nobody on an overclocking forum should be saying
"oh no, the multiplier is locked, what am I going to do"
Just like no technician is going to say, oh no, the file is 'hidden'
what am I going to do.

Better analogy: the technician saying "oh no, someone has wiped the disk
then turned it into slag in a blast furnace, what am I going to do?". Given
that people have spent close to 6 years trying to unlock Intel CPUs (no
success) and about 1 year trying to unlock locked AMD chips (no success),

6 years? - but there are loads of articles on unlocking AMD chips, i'm
sure I think I saw one for the AMD XP 1500+, that's less than 6 years
old isn't it?

The general view is
that both companies are using fuses inside the die, which can't be altered
once set.

*******s.
So how can anybody overclock? Just by upping the FSB to whatever the
mobo supports?
I suppose that a CPU will have a built in multiplier at a fixed value,
and will assume a certain FSB speed. So if the FSB is lower then it's
underclocked. If it's higher then it's overclocked. Or does it not
even derive its clock by multiplying the FSB clock?
Would most people have the FSB at the highest setting suported anyway,
and they'd have a CPU that supports it, so how would they overclock?
(they cna't up the FSB clock because it's already on the highest, and
they can't up the multiplier because it's properly locked)

also higher FSB = higher bandwidth = higher performance.

yeah, if it's greater width. i'm talking about speed only though.

Umm, say what? It's obvious that more throughput = more performance, and
throughput = bus width * bus speed, so increasing the bus speed (FSB)
obviously increases performance. Or do you think a Athlon running sync with
PC66 RAM (66MHz FSB, SDR, 64 bits wide) would perform just as well as the
identical CPU running sync with PC3200 RAM (200MHz FSB, DDR, 64 bits wide)?

oh yeah, I just realised that in a post in reply to that other Geezer
in the thread.
btw, Some software tells me that my RAM is operating at a multiple of
the processor speed. I can put my FSB=100 and have 266MHZ
DDR-SDRAM(actual speed 133MHz) So si sandra tells me it's a multiple
of my FSB.
Is it correct that RAM uses a multiplier too? It sure looks like it
from si sandra, though there is no option in the BIOS to set it, I can
only set the ram frequency. I thought that RAM derives its speed from
the FSB, the FSB is like the base clock, so it must multiply it,
strange that there's no option in the bios to set the ram multiplier.

try unlocking an A64 or a P3/P4

XP's yeah sure you can unlock them, but why? the higher the fsb the better

--
From Adam Webb, Overlag
www.tacticalgamer.com
CS:SOURCE server now active
"James Hanley" wrote in message
m...
"Michael Brown" wrote in message
...
James Hanley wrote:
"Adam Webb" wrote in message
...
it seems to me that nobody needs a high fsb. since they could just
push the multiplier really high.

you cant push the multiplier high because its locked on most modern
CPU's

nobody on an overclocking forum should be saying
"oh no, the multiplier is locked, what am I going to do"
Just like no technician is going to say, oh no, the file is 'hidden'
what am I going to do.

Better analogy: the technician saying "oh no, someone has wiped the disk
then turned it into slag in a blast furnace, what am I going to do?".
Given
that people have spent close to 6 years trying to unlock Intel CPUs (no
success) and about 1 year trying to unlock locked AMD chips (no
success),

6 years? - but there are loads of articles on unlocking AMD chips, i'm
sure I think I saw one for the AMD XP 1500+, that's less than 6 years
old isn't it?

The general view is
that both companies are using fuses inside the die, which can't be
altered
once set.

*******s.
So how can anybody overclock? Just by upping the FSB to whatever the
mobo supports?
I suppose that a CPU will have a built in multiplier at a fixed value,
and will assume a certain FSB speed. So if the FSB is lower then it's
underclocked. If it's higher then it's overclocked. Or does it not
even derive its clock by multiplying the FSB clock?
Would most people have the FSB at the highest setting suported anyway,
and they'd have a CPU that supports it, so how would they overclock?
(they cna't up the FSB clock because it's already on the highest, and
they can't up the multiplier because it's properly locked)

also higher FSB = higher bandwidth = higher performance.

yeah, if it's greater width. i'm talking about speed only though.

Umm, say what? It's obvious that more throughput = more performance, and
throughput = bus width * bus speed, so increasing the bus speed (FSB)
obviously increases performance. Or do you think a Athlon running sync
with
PC66 RAM (66MHz FSB, SDR, 64 bits wide) would perform just as well as
the
identical CPU running sync with PC3200 RAM (200MHz FSB, DDR, 64 bits
wide)?

oh yeah, I just realised that in a post in reply to that other Geezer
in the thread.
btw, Some software tells me that my RAM is operating at a multiple of
the processor speed. I can put my FSB=100 and have 266MHZ
DDR-SDRAM(actual speed 133MHz) So si sandra tells me it's a multiple
of my FSB.
Is it correct that RAM uses a multiplier too? It sure looks like it
from si sandra, though there is no option in the BIOS to set it, I can
only set the ram frequency. I thought that RAM derives its speed from
the FSB, the FSB is like the base clock, so it must multiply it,
strange that there's no option in the bios to set the ram multiplier.


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Obviously I see the benefit of more cycles. What do you think I meant
when I said "push the multiplier really high". That increases the
cycles per second.

theres no point having a 2000mhz CPU if its connection to the rest of the
system is only 100mhz.

if the ram is running at 200mhz, and the fsb is running at 100mhz do you
really think it gets max performance out of the ram? no it just sits there
waiting for stuff to do, exaclty what the CPU does also, sure it can do
stuff at 2000mhz but it has to send it down a small 100mhz pipe, dont you
think thats a rather SLOW way of doing things?

the fsb is the limit on todays systems hence the reason for pushing it so
high, id much rather have a 8x250 than a 10x200 A64 system.


Oh and about the locks:

Intel P3 and P4s can not be unlocked (ES dont count)
A64s cant go up on multiplyers, just down.
FX's are totaly unlocked.
2003 week 39 XP's are unlockable, but alittle harder than before
2003 week 39 XP's are unlockable with ease.


--
From Adam Webb, Overlag
www.tacticalgamer.com
CS:SOURCE server now active


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Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
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On 31 Oct 2004 04:21:20 -0800, (James
Hanley) wrote:

GTD wrote in message . ..
Obviously I see the benefit of more cycles. What do you think I meant
when I said "push the multiplier really high". That increases the
cycles per second.

CPU cycles = yes, memory frequency = no. Only raising the FSB
increases the speed at which the CPU can access the memory.
----------------------------------------------------------------------

memory frequency can be increased to a multiple of the FSB even before
DDR is 'applied'. I have an option in my BIOS to set my DDR-SDRAM
frequency, I can set my FSB to 100 and my SDRAM to 266 (effective).
So my actual RAM speed is operating at a frequency of 133 internally,
which is FSB*(5/4). I don't know if it uses its own multiplier to do
that, I think it probably does.
So both RAM and CPU can operate at a frequency that is a multiple of
the FSB.
So memory frequency can be increased without increasing the FSB.
Yes, that is correct


However, against me, I will say that it just occurred to me that the
speed at which the CPU and RAM interfaces with the FSB is still going
to be the speed of the FSB, regardless of how high their internals
speeds are.
Yes, that is what I was trying to articulate. I forgot about the
presence of FSB/Memory Dividers

Thus if one were to weigh doubling the FSB against
doubling the Multiplier(timesing the current value of the multiplier
by 2), they would find that doubling the FSB makes for a faster
computer, since it would have doubled not just both the internal
frequency of the CPU and RAM - thus their bandwidth, but the speed
and thus bandwidth of the bus.

(i'm assuming bandwidth=throughput, but I cannot check at this moment,
since I'm leaving in a minute, so I have to click Send now!!

Thanks for your response.

----------------------------------------------------------------------

You should start drinking prune juice and KY jelly cocktails right now,
that will make things a lot smoother.
-Felatio Love