Over/Underclocking motherboards on the fly without rebooting

[Will]

I'm interested in being able to both overclock (when working with HD videos) and underclock (when I'm doing nothing special) for
efficiency as I'd like to be able to have a mobile office in a van and need to conserve power as much as possible. Will be using a
low wattage LCD or LED 22"-24" monitor with a very efficient power supply (probably multiple Picos that are 95% efficient
apparently). Has anyone done this? I need to be able to change the clock speed on the fly without rebooting. That would make it
most convenient and mean I'm using less power more of the time. Opinions welcomed.

 

[JS]

I'm interested in being able to both overclock (when working with HD
videos) and underclock (when I'm doing nothing special) for efficiency as
I'd like to be able to have a mobile office in a van and need to conserve
power as much as possible. Will be using a low wattage LCD or LED 22"-24"
monitor with a very efficient power supply (probably multiple Picos that
are 95% efficient apparently). Has anyone done this? I need to be able
to change the clock speed on the fly without rebooting. That would make
it most convenient and mean I'm using less power more of the time.
Opinions welcomed.

Is this a home built computer if so please
post motherboard make and model.

If it's a store bought computer you most
likely will not be able to do this as the BIOS
may not have the options you need.

 

[Paul]

I'm interested in being able to both overclock (when working with HD
videos) and underclock (when I'm doing nothing special) for efficiency
as I'd like to be able to have a mobile office in a van and need to
conserve power as much as possible. Will be using a low wattage LCD or
LED 22"-24" monitor with a very efficient power supply (probably
multiple Picos that are 95% efficient apparently). Has anyone done
this? I need to be able to change the clock speed on the fly without
rebooting. That would make it most convenient and mean I'm using less
power more of the time. Opinions welcomed.

You could start with a processor like this.

Intel Core2 Q9550S Yorkfield 2.83GHz 12MB L2 Cache LGA 775 65W Quad-Core $350.00

http://www.newegg.com/Product/Product.aspx?Item=N82E16819115210

The product has support for deeper sleep states, as well as being
a slightly lower power processor to start with. (My assumption here,
is that you want a quad core.) I haven't attempted to do any research
on the deeper sleep states, so don't know what motherboards or BIOS
or OSes support it. In at least some cases, attempting to monitor
whether you're in a deep sleep state, prevents the system from
entering deep sleep. So it's tricky stuff.

http://processorfinder.intel.com/details.aspx?sSpec=SLGAE

There are some charts here, of various motherboards that were tested. Generally,
the newest motherboards feature slightly higher power consumption. This is a
fair amount of load to run in your van, even at idle.

http://www.bit-tech.net/hardware/motherboards/2008/08/20/gigabyte-ga-ep34-ds3r/12

You have two controls to start with, for overclocking. They are the FSB clock setting,
and the multiplier choice. On certain AMD and Intel processors, the multiplier
is unlocked. On AMD, they're the "Black" processors. On Intel, they're the
"Extreme" processors. Using multiplier control alone, is pretty
convenient, and marginally safer in theory, than ramping the FSB up and down.

As an example, take EIST (SpeedStep). The Intel processor has two sets
of controls. One called FID, and one called VID. FID is the multiplier
value. On a locked processor, the range of values is limited. (I
don't remember my exact values for sure - they could have ranged from
6X to 13X, where 13X gives me 2.6GHz.) If you try to write outside that
value, the value is stopped at the limit value. If the processor is unlocked,
the upper limit at least, is only limited by the processor crashing. I
presume the register is wide enough, so I can write a value which will
cause the processor to crash.

The VID is supposed to change, over that frequency range as well.
Say my processor has VID_min of 1.000 volts and VID_max of 1.300 volts.
Now, 1.300 volts might not be enough for me to hit 3.5GHz. Again, inside
the processor, the register controlling VID, is limited. If I write
"give me 1.5 volts" in the register, it'll give me 1.300 volts. A
Vcore voltage regulator designed for overclocking, has a separate
boost control. On my board, I added my own (as the regulator chip
design makes it dead simple), and I added +0.1 V all the time, to
Vcore. That is how I escape the limits imposed by the Intel VID register
scheme. But it does mean, my range ends up being 1.100 volts to
1.400 volts, so my low end is higher than it should be. If the boost
range was programmable (not, in my case), then a wider range of
Vcore could be arranged.

So the processor designs (both AMD and Intel), support changing
FID and VID on the fly, with perfect stability. I presume each
part is tested and characterized at the factory, to guarantee the
two limit values.

The third control is the FSB clock. The clock generator chip,
creates a reference input frequency to the chipset and CPU.
Cranking that clock value, increases both the CPU and memory
speed. That offers options for people with limited multiplier
(FID) values. So if my processor had 9X max multiplier, I
could boost my CPU input clock to 500MHz, to get 4.5GHz
with lots of Vcore boost.

SETFSB, is an example of a program that "slews" the FSB clock
on the fly. It does the frequency slew, one step at a time,
on the assumption that if you go slow, it won't crash the
system, and all the PLLs will track the change. So you can
go from 266MHz to 400MHz, and it might take 30 seconds
for the program to finish the slow ramp process.

Anyway, that is a very basic overview, with plenty of details
about how to dial in a system missing. The compromise in your case,
is to get support from programs such as SETFSB, you might need
to buy a popular overclocker motherboard. But the popular
overclocker motherboard may draw more watts due to having
an overvolted chipset. So you really cannot expect "popular"
and "wide ranging conditions" in the same package. Your
setup is more likely to solve your "overclocking" requirement
well, with poorer support for the "underclocking" to save
power requirement. At idle, you could well find that the
motherboard chipset, burns up more power than the processor
is using at idle/halt_state.

*******
Multiplier control programs (similar effects to EIST/Cool N' Quiet)
Control FID and VID. RMClock is more complicated, as it offers to
add a Power Scheme to the Power control panel, for full automation.
For fooling around, I think CrystalCPUID satisfied my curiosity
faster. I like RMClock more for the "throttle" detection graph
capability.

http://crystalmark.info/download/ ( CrystalCPUID )
http://cpu.rightmark.org/products/rmclock.shtml ( Rmclock )
*******

FSB clock input controls. You must check that the clockgen chip is supported!
Very important before buying a motherboard, unless you're a rich guy
and are buying an unlocked processor of some sort. Unlocked AMD processors
are cheaper than unlocked Intel processors.

Each software program, usually includes a list of supported clockgen part
numbers. Custom support for each one, means work for the developer. There are
more than 1000 different clockgen chips in existence. Only a small
percentage are covered. I've been lucky, that three of my motherboards
were on one of the lists.

clockgen (CPUID.com - No longer developed ?)
softfsb (H.Oda - No longer developed?)
setfsb http://www13.plala.or.jp/setfsb/ <--- tried this on my board
*******

To overclock, voltage and frequency go hand in hand. More voltage
is needed for higher frequencies. To prevent overclocking, Intel
capped the VID control register. Motherboard makers responded by
adding "boost" to the control loop. Since the boost is not
controlled via the VID register, it means control is broken up.
On my board, where I added my own boost, the boost is enabled
at all times. So I waste power, when the computer is idle.
I don't know if any boost schemes are tied into VID (such as
simply multiplying the VID value digitally, in a ROM, to make
new VID values). Even the voltage regulator itself has limits,
as it is compliant with the Intel defined VRD/VRM specs. Sometimes
a VRD/VRM spec is too restrictive, and enthusiasts need more voltage
than the top VRD/VRM value. That was true on my Northwood processor.
On Core2 45nm processors, it is not true. Going too high on a 45nm
processor can damage it, so you have to be careful with 45nm, and
a little less so with 65nm.

You could write a book on this subject, and you really need to do
your own research, and take responsibility for damaging your
own hardware

I'm not currently overclocking my system, as it just isn't worth
the fuss. I ran at 3.45GHz long enough to do some test cases,
and then set it back to stock.

Have fun, and keep a backup battery in the van, so you can start it

Paul

 

[Will]

I'm interested in being able to both overclock (when working with HD videos) and underclock (when I'm doing nothing special) for

Is this a home built computer if so please post motherboard make and model.

I was hoping for someone to recommend a decent motherboard manufacturer (Intel, Asus, MSI, Gigabyte, Abit, etc) that might be able
to do this.

 

[Will]

I'm interested in being able to both overclock (when working with HD videos) and underclock (when I'm doing nothing special) for

You could start with a processor like this. Intel Core2 Q9550S Yorkfield 2.83GHz 12MB L2 Cache LGA 775 65W Quad-Core $350.00
http://www.newegg.com/Product/Product.aspx?Item=N82E16819115210

The product has support for deeper sleep states, as well as being
a slightly lower power processor to start with. (My assumption here,
is that you want a quad core.)

I don't think I'll need the speed of a quad core as many dual cores can now overclock past 3 ghz on air easily. That will be plenty
fast enough for my needs I think.

I haven't attempted to do any research on the deeper sleep states,

Don't know what you mean by "deeper sleep states". I never mentioned sleep. I just need to underclock it most of the time then
have the ability to overclock it quickly when I need more power.

so don't know what motherboards or BIOS
or OSes support it. In at least some cases, attempting to monitor
whether you're in a deep sleep state, prevents the system from
entering deep sleep. So it's tricky stuff.

Don't need sleep state of any kind. When I use it its on. When I'm not using it it goes to Standby. That works fine for me.

http://processorfinder.intel.com/details.aspx?sSpec=SLGAE
There are some charts here, of various motherboards that were tested. Generally,
the newest motherboards feature slightly higher power consumption. This is a
fair amount of load to run in your van, even at idle.

Yes - hence the necessity for underclocking as much as possible.

http://www.bit-tech.net/hardware/motherboards/2008/08/20/gigabyte-ga-ep34-ds3r/12

You have two controls to start with, for overclocking. They are the FSB clock setting,
and the multiplier choice. On certain AMD and Intel processors, the multiplier
is unlocked. On AMD, they're the "Black" processors. On Intel, they're the
"Extreme" processors. Using multiplier control alone, is pretty
convenient, and marginally safer in theory, than ramping the FSB up and down.

As an example, take EIST (SpeedStep). The Intel processor has two sets
of controls. One called FID, and one called VID. FID is the multiplier
value. On a locked processor, the range of values is limited. (I
don't remember my exact values for sure - they could have ranged from
6X to 13X, where 13X gives me 2.6GHz.) If you try to write outside that
value, the value is stopped at the limit value. If the processor is unlocked,
the upper limit at least, is only limited by the processor crashing. I
presume the register is wide enough, so I can write a value which will
cause the processor to crash.

The VID is supposed to change, over that frequency range as well.
Say my processor has VID_min of 1.000 volts and VID_max of 1.300 volts.
Now, 1.300 volts might not be enough for me to hit 3.5GHz. Again, inside
the processor, the register controlling VID, is limited. If I write
"give me 1.5 volts" in the register, it'll give me 1.300 volts. A
Vcore voltage regulator designed for overclocking, has a separate
boost control. On my board, I added my own (as the regulator chip
design makes it dead simple), and I added +0.1 V all the time, to
Vcore. That is how I escape the limits imposed by the Intel VID register
scheme. But it does mean, my range ends up being 1.100 volts to
1.400 volts, so my low end is higher than it should be. If the boost
range was programmable (not, in my case), then a wider range of
Vcore could be arranged.

So the processor designs (both AMD and Intel), support changing
FID and VID on the fly, with perfect stability. I presume each
part is tested and characterized at the factory, to guarantee the
two limit values.

The third control is the FSB clock. The clock generator chip,
creates a reference input frequency to the chipset and CPU.
Cranking that clock value, increases both the CPU and memory
speed. That offers options for people with limited multiplier
(FID) values. So if my processor had 9X max multiplier, I
could boost my CPU input clock to 500MHz, to get 4.5GHz
with lots of Vcore boost.

SETFSB, is an example of a program that "slews" the FSB clock
on the fly. It does the frequency slew, one step at a time,
on the assumption that if you go slow, it won't crash the
system, and all the PLLs will track the change. So you can
go from 266MHz to 400MHz, and it might take 30 seconds
for the program to finish the slow ramp process.

Anyway, that is a very basic overview, with plenty of details
about how to dial in a system missing. The compromise in your case,
is to get support from programs such as SETFSB, you might need
to buy a popular overclocker motherboard. But the popular
overclocker motherboard may draw more watts due to having
an overvolted chipset. So you really cannot expect "popular"
and "wide ranging conditions" in the same package. Your
setup is more likely to solve your "overclocking" requirement
well, with poorer support for the "underclocking" to save
power requirement. At idle, you could well find that the
motherboard chipset, burns up more power than the processor
is using at idle/halt_state.

Those are valuable points you make. I'll keep an eye out for that. It may turn out to be best to use 2 systems - one designed
specifically for underclocking and another for overclocking. Hardware is so cheap these days it doesn't make so much difference I
suppose.

 

[Paul]

Don't know what you mean by "deeper sleep states". I never mentioned
sleep. I just need to underclock it most of the time then have the
ability to overclock it quickly when I need more power.

See the section here "C2E and C4E States and Intel VRD 11.1".
When a processor is idle, it doesn't need to do anything until the
next clock tick interrupt occurs. It is possible to put the processor
in a sort of "micro sleep" state, when that happens. So the processor
is not sleeping, like when you go to Start:Turn Off Computer and
select Standby. It is sleeping for some number of milliseconds.
Apparently, one possible option, is to drop Vcore for those
milliseconds, invalidating the cache, and keeping leakage current
pretty low. So these C states, are variations on Halt, Stop Grant
(bus disconnect) and the like. They're improvements in the ways
that subsystems on the processor can be shut down, for milliseconds
at a time.

http://www.bit-tech.net/hardware/motherboards/2008/08/20/gigabyte-ga-ep34-ds3r/12

In a processor design, if you do some of that stuff too much, the
result can be slow real time response, when the processor load is
cyclic. Anandtech has noticed a problem with video playback
on AMD processors, when Cool N' Quiet is enabled. So there
is a balance that needs to be struck, when enabling features that
put the processor into a millisecond sleep condition.

Anandtech had an article a while back, where they tried to get one
of those C states working on a laptop, and there was some issue
with Windows and the USB driver, preventing the processor
from using less power. And in that bit-tech article, there is
similar evidence, that one of the magic states is not working
right. Just the act of attempting to monitor the state, by
having a process active looking for it, can raise the utilization
level of the processor high enough, that the ACPI code doesn't
bother to use the lowest power states.

I did a quick look, for an article that explains all the C-states
in detail. But I didn't find anything I liked. There must be an article
around somewhere, that does a good job of explaining them. I doubt
the ACPI spec would have that kind of detail, as you wouldn't expect
processor technology advancements to be embedded in the spec.

For all the concentration on the processor, there are plenty of
other things in the computer that could use a look as well. Some of my
older hard drives might be 12 watts, while a new SSD could be around 2 watts.
If you used cheesy built-in motherboard graphics, instead of a video card,
that might save 25 watts. So there are other things you could look at.

Paul

 

[JS]

Gigabyte X38-DQ6:
User's Manual:
http://www.gigabyte.us/Products/Motherboard/Products_Overview.aspx?ProductID=2730

 

[Ian D]

I was hoping for someone to recommend a decent motherboard manufacturer
(Intel, Asus, MSI, Gigabyte, Abit, etc) that might be able to do this.

Asus boards with AI Suite will do what you want. It has several
utilities such as TurboV which allows you to change frequencies
and voltages from the OS. EPU-6 Engine will allow you to set up
parameters so that the frequencies and voltages will auto adjust
to system loads according to your settings.

 

[Will]

Asus boards with AI Suite will do what you want. It has several
utilities such as TurboV which allows you to change frequencies
and voltages from the OS. EPU-6 Engine will allow you to set up
parameters so that the frequencies and voltages will auto adjust
to system loads according to your settings.

Ian, that sounds like great news. Any idea how long it actually takes to go from an underclocked state to an overclocked state or
vice versa?

 

[Will]

I think this is the page:
http://www.gigabyte.us/FileList/NewTech/2006_motherboard_newtech/tech_20060605_speed.htm
But it really doesn't explain it much!

 

[Ian D]

Ian, that sounds like great news. Any idea how long it actually takes to
go from an underclocked state to an overclocked state or vice versa?

If you do it manually using TurboV, it would be instananeous.
With EPU-6 Engine, the changes will occur when your preset
conditions are met.

 

[JS]

I think this is the page:
http://www.gigabyte.us/FileList/NewTech/2006_motherboard_newtech/tech_20060605_speed.htm
But it really doesn't explain it much!

This is the manual:
http://europe.giga-byte.com/FileList/Manual/motherboard_manual_ga-x38t-dq6_e.pdf
Go to page #55 (C.I.A.2).
"CPU Intelligent Accelerator 2 (C.I.A.2) is designed to automatically adjust
CPU computing power
to maximize system performance. C.I.A.2 allows your system bus to be changed
dynamically
based on CPU loading through the use of 5 preset states."

With EIST turned on/Enabled (see pages 43 & 44)
you can take a 2.66GHz Quad Core from about
1.6GHz at idle to 2.66GHz at full load.

Here is the part your interested in:
With EIST and CIA2 Enabled (page 54) with the
"Sports" setting (page 55). you can take same Quad Core
from about 1.6GHz at idle to 2.88GHz at full load (9% overclock).

There are 3 additional CIA2 settings that can increase the
overclock up to 19% above the stock CPU speed. But you
better make certain that your CPU cooler, Memory and
other factors allow your system to run overclocked without
crashing.

Easy Tune:
It's "Easy" but it also adjusts some BIOS settings behind the
scenes and one wrong move will end up with either a non
bootable system or all the BIOS settings will revert back to their defaults.

 

[Will]

I'm interested in being able to both overclock (when working with HD

This is the manual:
http://europe.giga-byte.com/FileList/Manual/motherboard_manual_ga-x38t-dq6_e.pdf
Go to page #55 (C.I.A.2).
"CPU Intelligent Accelerator 2 (C.I.A.2) is designed to automatically adjust
CPU computing power
to maximize system performance. C.I.A.2 allows your system bus to be changed
dynamically
based on CPU loading through the use of 5 preset states."

With EIST turned on/Enabled (see pages 43 & 44)
you can take a 2.66GHz Quad Core from about
1.6GHz at idle to 2.66GHz at full load.

Here is the part your interested in:
With EIST and CIA2 Enabled (page 54) with the
"Sports" setting (page 55). you can take same Quad Core
from about 1.6GHz at idle to 2.88GHz at full load (9% overclock).

There are 3 additional CIA2 settings that can increase the
overclock up to 19% above the stock CPU speed. But you
better make certain that your CPU cooler, Memory and
other factors allow your system to run overclocked without
crashing.

Easy Tune:
It's "Easy" but it also adjusts some BIOS settings behind the
scenes and one wrong move will end up with either a non
bootable system or all the BIOS settings will revert back to their defaults.

Interesting link but why would anybody bother with 19% overclock? Most people overclock 50-80%.

 

[JS]

Interesting link but why would anybody bother with 19% overclock? Most
people overclock 50-80%.

To overclock properly at much more than
20% you are going to need a better heatsink and
cooler than the stock Intel unit. Memory must also
be able to run at the higher FSB frequencies and have
good heat spreaders.

Northbridge voltage may need to be jacked up
along with DRAM and other voltages. Case cooling
need to be very good to get the heat out and the power
supply must handle the extra load, just to mention a few
things.

Now as to the time spent on tweaking to get a stable
overclock it depends. Socket 478 were easy for most
anyone to overclock. With the Socket 775 processors
the number and complexity of BIOS adjustments increased
significantly. Socket 1366 (Core i7) processors requires
even more skill without ending up with a fried processor.

Socket 1156 (Core i5 and i7 8xx) processors have just
been released in the last week so I haven't had a chance
to overclock one of these yet. Plus some of these new
processors have the ability to shut down some of the cores
for better power management and automatically overclock
for some single threaded applications.

From your original post you said nothing about extreme
overclocking or Core i7 Extreme processors. So I assumed
you wanted a mild and generally safe overclock.

Besides, overclocking is not the end all be all to improving
your computers performance. High end enterprise level hard
drives, RAID, or Solid State Drives (SSD), Video card(s)
can also improve performance.

 

[Will]

This is the manual: http://europe.giga-byte.com/FileList/Manual/motherboard_manual_ga-x38t-dq6_e.pdf

To overclock properly at much more than
20% you are going to need a better heatsink and
cooler than the stock Intel unit.

No problem. Heatsinks are cheap. I have several high end ones now. Scythe, Thermalright, Thermaltake, etc.

Memory must also
be able to run at the higher FSB frequencies and have
good heat spreaders.

No problem. Memory is dirt cheap. If I don't have it I'll buy it.

Northbridge voltage may need to be jacked up
along with DRAM and other voltages.

I wonder if software overclockers that run in Windows can take into account all these parameters? CPU, Northbridge, Ram, etc.

Case cooling need to be very good to get the heat out and the power
supply must handle the extra load, just to mention a few things.

I have my own case design that runs things absurdly cool. The key is to have no horizontal items obscuring the heat from rising and
escaping. Like optical drives and hard drives.

Now is the time to spend on tweaking to get a stable
overclock it depends. Socket 478 were easy for most
anyone to overclock. With the Socket 775 processors
the number and complexity of BIOS adjustments increased
significantly. Socket 1366 (Core i7) processors requires
even more skill without ending up with a fried processor.

Socket 1156 (Core i5 and i7 8xx) processors have just
been released in the last week so I haven't had a chance
to overclock one of these yet. Plus some of these new
processors have the ability to shut down some of the cores
for better power management and automatically overclock
for some single threaded applications.

Sounds like good potential there for efficiency.

From your original post you said nothing about extreme
overclocking or Core i7 Extreme processors. So I assumed
you wanted a mild and generally safe overclock.

Yes. The Core 2 Duo Intels often went from the stock speed of about 2ghz to over 3ghz easily. Now if I could underclock that down
closer to 1ghz, that would give me tremendous range.

Besides, overclocking is not the end all be all to improving
your computers performance. High end enterprise level hard
drives, RAID, or Solid State Drives (SSD), Video card(s)
can also improve performance.

I'd like to experiment with Raid 0 in 4 x 40gb 7200 rpm Sata drives which are about $10 each if bought used in lots. But that is a
little later. Another interesting option is to watch for eSata Flash Memory sticks. If they come down much, and are available in
very small sizes, one could run several in Raid 0 for your OS and programs.

 

[JS]

I wonder if software overclockers that run in Windows can take into
account all these parameters? CPU, Northbridge, Ram, etc.

< Snipped>

Gigabytes's Easy Tune will adjust these parameters, but there are at least
two problems.
1) Easy Tune will let you push the processor speed up until you see a
message to "Reboot", then you know you have overclocked too far and after
rebooting the BIOS will end up back to the defaults, most BIOS changes you
have made will be lost.
2) Easy Tune will increase the CPU core voltage beyond the max specified by
Intel, it does this dynamically and as a result you find out after the fact
that the voltage is way too high.

Easy Tune does not care about temperatures.
For that you either need to set BIOS limits/Warnings or use a separate
utility.

 

[Will]

I wonder if software overclockers that run in Windows can take into

Gigabytes's Easy Tune will adjust these parameters, but there are at least
two problems.
1) Easy Tune will let you push the processor speed up until you see a
message to "Reboot", then you know you have overclocked too far and after
rebooting the BIOS will end up back to the defaults, most BIOS changes you
have made will be lost.
2) Easy Tune will increase the CPU core voltage beyond the max specified by
Intel, it does this dynamically and as a result you find out after the fact
that the voltage is way too high.

Easy Tune does not care about temperatures.
For that you either need to set BIOS limits/Warnings or use a separate
utility.

Good points. Temps are not a problem. But the first 2 points are very valid. Thanks.

 

[JS]

You're welcome.