CPU speeds and bus speeds.

[half_pint]

As I understand it, whilst CPU speeds have increased several fold over
the past 10 years, bus speeds have barely doubled.

So.. is your Pentium 9. 'SuperFatBastard' 4.0 GHZ CPU really going to things
15 times faster than my Cyrix 'Tortoise' 266 Mhz?

half_pint.

 

[JT]

As I understand it, whilst CPU speeds have increased several fold over
the past 10 years, bus speeds have barely doubled.

So.. is your Pentium 9. 'SuperFatBastard' 4.0 GHZ CPU really going to things
15 times faster than my Cyrix 'Tortoise' 266 Mhz?

half_pint.

Considering that Cyrix was a PR rated chip (actual speed was probably
200mhz), with marginal performance partly caused by a small cache and very
poor FPU, I would expect that many current processors would be 15 times as
fast. Add in much faster memory, faster disk drives, much faster video
cards, basically faster everything, and a 15x speed up is not really that
far fetched. That is unless you are still stuck on a 56k dial up
internet connection, in which case your internet is just about as slow as
it ever was.

JT

 

[Eric Gross]

As I understand it, whilst CPU speeds have increased several fold over
the past 10 years, bus speeds have barely doubled.

So.. is your Pentium 9. 'SuperFatBastard' 4.0 GHZ CPU really going to things
15 times faster than my Cyrix 'Tortoise' 266 Mhz?

half_pint.

Your Cyrix's 66Mhz system bus is quite a bit slower than a newer P4's 200Mhz
Quad-Pumped (effectively 800Mhz) system bus. That's over a 12x increase in
raw bus bandwidth right there. Additonally, the 66Mhz SDRAM your system is
probably running can only transfer 500MB/sec or so (I don't even remember
any chipsets actually ever managed to hit that kind of theoretical speed
anyways). Compared to a modern dual-channel DDR400 system that can push
5-6GB of memory bandwidth, that's about 10x slower. So yeah, there's a huge
difference in speed....

-Eric

 

[Matt Merkey]

As I understand it, whilst CPU speeds have increased several fold over
the past 10 years, bus speeds have barely doubled.

So.. is your Pentium 9. 'SuperFatBastard' 4.0 GHZ CPU really going to things
15 times faster than my Cyrix 'Tortoise' 266 Mhz?

half_pint.

Is this a trick question?

Just for the sake of the uninformed, while the latest processors,
especially ones from a certain brand (*cough*Intel*cough*), are a bit
ridiculous with their 733 mHz busses and multiple gigahertz CPU's, they
are going to be just a tad bit faster than your old Cyrix. A tad being
relative, when I say a tad faster, I mean something like Niagara Falls
puts out a tad of water.

 

[half_pint]

Considering that Cyrix was a PR rated chip (actual speed was probably
200mhz), with marginal performance partly caused by a small cache and very
poor FPU, I would expect that many current processors would be 15 times as
fast. Add in much faster memory, faster disk drives, much faster video
cards, basically faster everything, and a 15x speed up is not really that
far fetched. That is unless you are still stuck on a 56k dial up
internet connection, in which case your internet is just about as slow as
it ever was.

I think the limit on bus speed is about 200mhz without 'tricks'.
My machine is capable of surfing the net just as fast as one
with a 'SuperFatBastard' processor. CPU speed is irrelevant
surfing speed to, just as the size of the ash tray is irrelevant to
a cars top speed.

 

[half_pint]

Your Cyrix's 66Mhz system bus is quite a bit slower than a newer P4's 200Mhz
Quad-Pumped (effectively 800Mhz) system bus. That's over a 12x increase in
raw bus bandwidth right there. Additonally, the 66Mhz SDRAM your system is
probably running can only transfer 500MB/sec or so (I don't even remember
any chipsets actually ever managed to hit that kind of theoretical speed
anyways). Compared to a modern dual-channel DDR400 system that can push
5-6GB of memory bandwidth, that's about 10x slower. So yeah, there's a huge
difference in speed....

-Eric

I was looking at a chart posted in this group (recently) which showed the
history
of cpu and bus speeds. I was surprised at how low the modern bus speeds
were on may of the newer models whilst the cpu speed seemed to
have increased considerably.
A lot of the bus speeds were 100mhz which is not much faster than my 66mhz.
Some were a bit higher but they looked very recent ones with various
'tricks'

Unfortunately I cant find the chart again so I would be thanful if someone
could repost the link.


But will not harddrive speeds be basically the same anyway? 5400, 7200?
Making bus speed irrelvant on many operations?

 

[Eric Gross]

I think the limit on bus speed is about 200mhz without 'tricks'.
My machine is capable of surfing the net just as fast as one
with a 'SuperFatBastard' processor. CPU speed is irrelevant
surfing speed to, just as the size of the ash tray is irrelevant to
a cars top speed.

I don't see why you call the ways that bus speeds have increased "tricks."
Sure, the clock may be at only 200Mhz, but if you're transferring 4 pieces
of data every clock cycle, it is identical to an 800Mhz bus transferring one
piece of data per cycle. It removes the problem of distributing an 800Mhz
clock across a bus yet gets the same bandwidth.

As for CPU speed not affecting your websurfing speed, you're right that it
doesn't quite matter the difference between say a 3Ghz processor and a 4Ghz
one. However, modern pages using very complex nested tables and style sheets
are going to render a heck of a lot slower on your 200Mhz Cyrix than a
faster CPU. Perhaps you're using an outdated browser which doesn't handle
any of the fancy new additions and so you don't notice the speed difference?
Try downloading Mozilla 1.4 and tell me how many minutes (hours?) it takes
to start up on your Cyrix...

-Eric

 

[half_pint]

I was looking at a chart posted in this group (recently) which showed the
history
of cpu and bus speeds. I was surprised at how low the modern bus speeds
were on may of the newer models whilst the cpu speed seemed to
have increased considerably.
A lot of the bus speeds were 100mhz which is not much faster than my 66mhz.
Some were a bit higher but they looked very recent ones with various
'tricks'

Unfortunately I cant find the chart again so I would be thanful if someone
could repost the link.

Actually I have found it again.
http://www.tom.womack.net/x86FAQ/faq_time.html
Thats one for my favourites folder.

Take this line as an example. I know there are faster ones though.

15/05/02 Intel Celeron 1400 100 FCPGA2 Tualatin/256k

It has a bus speed of 100mhz not that much faster than mine,
and I think I could have bought a PC with a 100mhz bus when
I bought mine (if I was made of money).
Anyway its bus speed is 50% faster than mine but its CPU
speed is around 300% faster.

 

[Eric Gross]

15/05/02 Intel Celeron 1400 100 FCPGA2 Tualatin/256k

It has a bus speed of 100mhz not that much faster than mine,
and I think I could have bought a PC with a 100mhz bus when
I bought mine (if I was made of money).
Anyway its bus speed is 50% faster than mine but its CPU
speed is around 300% faster.

Yes, but keep in mind CPU's are designed to rely on *not* having to go to
the main bus for every piece of data. That is why we have caching. The
Tualatin you mentioned has 256KB of *on-die* cache running at full speed of
the processor. This is a heck of a lot faster than the external cache
sitting on the slow system bus that your Cyrix uses. By having a built-in
cache running at the full speed of the processor, the processors scale in
overall speed much better than being tied to a cache running at a slow,
fixed speed on the motherboard.

While memory bandwidth is important in many applications, raw cpu power is
often all that's needed. If you have an optimized algorithm that fits
entirely into the large cache on newer CPU's, the bus speed becomes
practically irrelevant to performance. Everyday applications do still get
benefit from faster bus speeds, but raw CPU power can make a huge difference
in many cases.

-Eric

 

[JT]

I think the limit on bus speed is about 200mhz without 'tricks'.

Lets just do a couple quick calculations here. According to what I can
find, your Cyrix is actually runnign at 3.5*66 (real speed 233). Means your
memory is running at 66mhz. raw clock speed, DDR 400 is 6 times as fast.
Make that Dual Channel, and you are 12 times as fast. Just on data that is
transferred to and from memory. DDR is not a "trick", but a better
technology. Same with dual channel.

My machine is capable of surfing the net just as fast as one
with a 'SuperFatBastard' processor. CPU speed is irrelevant
surfing speed to, just as the size of the ash tray is irrelevant to
a cars top speed.

As long as there is no multimedia, streaming video, video conferencing,
etc.. that make use of high compression ratios and lots of processor to
make up for the low band width you can get by. Throw in even a simple
online game on any broadband connection, and your Cyrix isn't even in the
game. As long as you just use it for Usenet, basic email, and other simple
browsing, you can get by for a little while longer. We are talking drive
trains and engines, not ashtrays to stay with you attempted automotive
analogy.JT

 

[half_pint]

Lets just do a couple quick calculations here. According to what I can
find, your Cyrix is actually runnign at 3.5*66 (real speed 233). Means your
memory is running at 66mhz. raw clock speed, DDR 400 is 6 times as fast.
Make that Dual Channel, and you are 12 times as fast. Just on data that is
transferred to and from memory. DDR is not a "trick", but a better
technology. Same with dual channel.

I don't quite get the DDR thing surely the data has to travel on the
data bus at speeds faster than the bus can handle.

I did read somewhere that DDR memory was nowhere near
twice as fast as normal ram, more like 10-15% faster, although
that article could well have been wrong. Actually I still have that
article somewhere.
This is the actual quote, word for word.

"So what is the advantage of DDR memory? Well the performance
advantage of DDR memory as opposed to SDRAM is normally around
5 to 10%.However with dome applications you will not any advantage at
all, but with memory intensive games you will notice up to 30%
improvement."

So going by that you system will not be hugely faster than mine but
around 3 times maybe?

As long as there is no multimedia, streaming video, video conferencing,
etc.. that make use of high compression ratios and lots of processor to
make up for the low band width you can get by. Throw in even a simple
online game on any broadband connection, and your Cyrix isn't even in the
game.

I am not even sure about that, even with fast broadband with
high compression I estimate my CPU easily cope.

Remember my CPU is running at 233 mhz.
Say you have a 1 megabit connection thats 62,500 16 bit
words a second or 31,750 32 bit words a second.
My 66mhz databus can transfer data *TWO THOUSAND TIMES*
faster. Os it will be mainly idle 90%of the time.

Playing music at my end and running a java internet application
can slow down the application though, but the reason may
not be my processor or bus. ( Probably my small upstream
channel).

As long as you just use it for Usenet, basic email, and other simple
browsing, you can get by for a little while longer. We are talking drive
trains and engines, not ashtrays to stay with you attempted automotive
analogy.

I can play pool online and voice chat at the same time.
I am unlikely ever to want to do much more.

 

[JT]

I don't quite get the DDR thing surely the data has to travel on the
data bus at speeds faster than the bus can handle.

I did read somewhere that DDR memory was nowhere near
twice as fast as normal ram, more like 10-15% faster, although
that article could well have been wrong. Actually I still have that
article somewhere.
This is the actual quote, word for word.

"So what is the advantage of DDR memory? Well the performance
advantage of DDR memory as opposed to SDRAM is normally around
5 to 10%.However with dome applications you will not any advantage at
all, but with memory intensive games you will notice up to 30%
improvement."

So going by that you system will not be hugely faster than mine but
around 3 times maybe?

With conventional SDRAM, data is only transfered on one edge (either rising
or falling) of the clock. With DDR, data is transfered on each edge. twice
the data in the same amout of time. When DDR first came out, and processors
were a lot slower than they are today, 10% was in the ball park for speed
increases seen. On chip cache, which had been designed was the main reason.
Processor speeds have more than doubled since that time, and cache alone
can't make up for the memory bottleneck.

I am not even sure about that, even with fast broadband with
high compression I estimate my CPU easily cope.

You seem to do a considerable amout of guessing about that which you have
no experiance with. I still have some machines around that are almost as
slow as your Cyrix. There is a lot of content that will not be useable on
your Cyrix. Pegs the CPU usage on faster machines easily.

Remember my CPU is running at 233 mhz.
Say you have a 1 megabit connection thats 62,500 16 bit
words a second or 31,750 32 bit words a second.
My 66mhz databus can transfer data *TWO THOUSAND TIMES*
faster. Os it will be mainly idle 90%of the time.

We are not talking just picking up a piece. We are talking about actually
doing something with it. It can easily take several thousand memory cycles
to process data from the internet into something on the screen. Add game
play logic, overhead for the protocols, interuptions from popup windows,
(or the overhead of the program that blocks them) and your Cyrix is pretty
well left in the dust.

Playing music at my end and running a java internet application
can slow down the application though, but the reason may
not be my processor or bus. ( Probably my small upstream
channel).

Music is not a terribly bandwidth hungry application. Java is running on
your machine, so your internet connection is not likely a major problem
there. You could always do something like actually look at processor load,
but it seems you would rather guess than learn the facts.

I can play pool online and voice chat at the same time.
I am unlikely ever to want to do much more.

In that case, it is adequate for your needs for today. Not for mine or most
of my customers and friends.

JT

 

[half_pint]

With conventional SDRAM, data is only transfered on one edge (either rising
or falling) of the clock. With DDR, data is transfered on each edge. twice
the data in the same amout of time.

This is where I have a slight problem.
Its a while since I looked at any bus timing diagrams for
computers but you appear be saying data is traveling at twice
the frequency of the clock, which it self is travelling as fast as the
bus can manage, which appears to be a contradiction but maybe
not. As i said I am a little 'rusty' on this

When DDR first came out, and processors
were a lot slower than they are today, 10% was in the ball park for speed
increases seen. On chip cache, which had been designed was the main

reason.

So you are saying most data is fetched from cache so bus speed (FSB)
doenst make that much difference.

Processor speeds have more than doubled since that time, and cache alone
can't make up for the memory bottleneck.

I see.

You seem to do a considerable amout of guessing about that which you have
no experiance with.

Well I admit I haven't familarised myself that much which the recent
technology untill recently. But I think 'guessing' is a bit over the top.

I still have some machines around that are almost as
slow as your Cyrix. There is a lot of content that will not be useable on
your Cyrix.

Such as?

Pegs the CPU usage on faster machines easily.
Pegs?


We are not talking just picking up a piece. We are talking about actually
doing something with it. It can easily take several thousand memory cycles
to process data from the internet into something on the screen.

If microsoft wrote the code maybe.
I have tried doing a search in regedit you know, which take a hundred or
more
times longer than necessary, as does most of the microsoft sh*te.

You can so a hell of a lot in 2000 cycles.

The big bandwith 'things' are file downloads which require minimal
processing.

Add game
play logic, overhead for the protocols, interuptions from popup windows,

Which contain data which has to be sent and would make zero difference
to through put.

(or the overhead of the program that blocks them) and your Cyrix is pretty
well left in the dust.

I very much doubt that.
I am pretty sure my machine would be just as quick as a modern one.

Music is not a terribly bandwidth hungry application. Java is running on
your machine, so your internet connection is not likely a major problem
there. You could always do something like actually look at processor load,
but it seems you would rather guess than learn the facts.

Says someone who hardly ever puts any facts in his posts!!!!!!

You are doing plenty of 'guessing' yourself so don't be so condescending.
I did look at the CPU when playing music just after I posted, I can't
do everything at once you know. I only have one pair of hands.
I presume you have DDR hands.

In that case, it is adequate for your needs for today. Not for mine or most
of my customers and friends.

Well please elabotate and don't leave me guessing what it is you do,
thats rather rich coming from someone who so dispised people
guessing isn't it don't you think!!!!

I can't think of anything which required more processing and anyway.
I doubt you disk drive can spin 10 times faster than mine!!
Nowhere near it infact.

 

[Eric Gross]

I am not even sure about that, even with fast broadband with
high compression I estimate my CPU easily cope.

Remember my CPU is running at 233 mhz.
Say you have a 1 megabit connection thats 62,500 16 bit
words a second or 31,750 32 bit words a second.
My 66mhz databus can transfer data *TWO THOUSAND TIMES*
faster. Os it will be mainly idle 90%of the time.

Ok, have a look at some of this multimedia content:
http://www.microsoft.com/windows/windowsmedia/content_provider/film/ContentShowcase.aspx

We're really not *that* far from the day that this level of high-definition
video is available in real-time over the internet. You have to be kidding if
you think your Cyrix can even attempt to play this video.


-Eric

 

[half_pint]

Ok, have a look at some of this multimedia content:
http://www.microsoft.com/windows/windowsmedia/content_provider/film/ContentShowcase.aspx

We're really not *that* far from the day that this level of high-definition
video is available in real-time over the internet.

Well we are a long time away from it.
You would need a 10 megabit per second line to download it in
real time.
Currently the recommended minumum specification for broadband
appears to be a 166mhz pentium.
So my machine should have no problem with broadband.

You have to be kidding if
you think your Cyrix can even attempt to play this video.

Well it would take me 5-10 hours to download it anyhow.
Hardly worth it for 2 minutes of video.

 

[Eric Gross]

Well we are a long time away from it.
You would need a 10 megabit per second line to download it in
real time.
Currently the recommended minumum specification for broadband
appears to be a 166mhz pentium.
So my machine should have no problem with broadband.

Well, I downloaded it at well over realtime 25+megabit/sec here (thank you,
Akamai), so its not that uncommon. Given that around 50% of households with
internet access in the US currently have broadband access, and pretty much
all broadband companies are looking to further compete as newer standards
become available for faster access, its really not hard to imagine the
current 3Mbit/sec most cable companies offer, for example, will not begin
moving to 10Mbit or more within the next few years.

-Eric

 

[half_pint]

Well, I downloaded it at well over realtime 25+megabit/sec here (thank you,
Akamai), so its not that uncommon. Given that around 50% of households with
internet access in the US currently have broadband access, and pretty much
all broadband companies are looking to further compete as newer standards
become available for faster access, its really not hard to imagine the
current 3Mbit/sec most cable companies offer, for example, will not begin
moving to 10Mbit or more within the next few years.

Well I am in the UK and most broadband is 512kbs few people
have faster connections, mainly because of the huge cost.
SOme companies even offer 150kbs as 250kbs as 'broadband'.

I should think the number of people with a 25mbs connection for
home use is probably 1 in a million and I expect that is the same for the UK
too.
The days of the average home user being able to watch such things realtime
are probably decades away. BY which time I might have upgraded my
computer anyway.

 

[Trent©]

This is the actual quote, word for word.

"So what is the advantage of DDR memory? Well the performance
advantage of DDR memory as opposed to SDRAM is normally around
5 to 10%.However with dome applications you will not any advantage at
all, but with memory intensive games you will notice up to 30%
improvement."

That's an exact quote? It doesn't seem to make any sense.


Have a nice week...

Trent

What do you call a smart blonde?
A golden retriever.

 

[half_pint]

That's an exact quote? It doesn't seem to make any sense.

Apart from a few typo's yes. dome/some
Source issue 178 of Micro Mart (UK) 1/1/03.
Obviously even doubling memory speed will not double overall performance.

Actually reading or writing RAM may only take a small proportion of
a computers processing time, most of the data it requires will be in it's
own registers or cached locally, so thinking about it it does sound fairly
reasonable.
Makes you wonder if forking out the extra cash is really worth it.
Upgrading my Cyrix CPU 266mhz would be a better option for me,
but that means a new motherboard :O(

half_pint