so one of the biggest downsides of
buying a locked intel cpu even in 2018
is that you get this thing included in
the box now this may be mistaken for a
piece of scrap metal but it's actually
the stock CPU cooler that comes included
with your CPU now this thing is
sufficient for the i3 80 180 300 but
when it comes to the i-5 series and even
the i7 series the i7 8700 actually ships
with this thing believe it or not it
definitely is not sufficient now combine
that with the automatic voltage
parameters that your motherboard assigns
and you've got a recipe for disaster and
in the worst case your CPU may even be
thermal throttling and costing you some
performance now although you can't
modify the voltage parameters in the
BIOS to correct this since they are
locked CPUs you can apply a voltage
offset in Intel's XTU software and also
a program called the throttle stop but
the purpose of this guide though we'll
be using XT use into the UI is a lot
more user-friendly I think and it also
has a monitoring graph built in before
we get started a quick briefing on what
under vaulting is and why you should
consider it if you're running either a
lock CPU or a processor which you're
running at stop clock speeds so the
basics of under vaulting are this there
are two variables that you should be
concerned with and when it comes to your
CPU that's the clock frequency and the
voltage referred to as V core now with
AMD's rise in CPUs and with Intel's
unlocked CPUs like the 8700 K you can
modify both of these in the BIOS and
establish an overclock for better
performance however if you're just
running the CPU on auto settings it's
common that your motherboard will be
assigning a higher than necessary
voltage to keep all programs stable
which results in a higher than necessary
temperature we can though decrease the
CPU voltage even with locked Intel CPUs
and this is very useful for those
wanting to run their systems as cool as
possible and also for those with
typically hot devices like laptops and
tablets allowing them to boost higher
and for longer which improves their
performance I recently under vaulted my
Microsoft Surface book to
and my score and Cinebench improved from
664 to 747 and thermals in gaming were a
few degrees better as well
under vaulting is also very useful for
small form-factor systems with otherwise
power-hungry processes that generate
quite a lot of heat so the locked CPU
that we're going to be under vaulting
today is Intel's i-5 8400 which is a six
core processor with a boost clock of up
to four gigahertz and we're going to be
locking that into a cheap h3 10
motherboard from asrock the i5 8400 does
come with Intel's stock cooler as well
and that's what we're going to be using
here and in prime95 with small FFTs
tested the CPU was sitting at a 6-quart
average of 88 point seven degrees C
after 10 minutes and although it didn't
fill more throttle it did get pretty
close with the peaks at 91 degrees C the
vehicle at these loads was not too bad
for a h3 10 motherboard I'll say at one
point one six volts but we can decrease
that by a good amount so the first thing
that you'll need to do is download
Intel's XTU software this is a great
piece of software which allows you to
change the V call for the majority of
locked Intel CPUs but it also has a neat
monitoring section down the bottom which
also lets you know if you're running
into any limits note that you can also
use a software called floral stop as I
mentioned previously but the UI isn't as
clean or easy to navigate for beginners
now before we start modifying anything
we want to download a stress test to
test the CPU stability I recommend
prime95 testing small FFTs as it puts
the CPU under the most stress possible
and generates the maximum heat it may be
overkill for most people though so feel
free to use something less demanding
like I 264 or a render program like
Cinebench r15 alright so let's go back
into the Intel XTU software and we're
going to modify this parameter here
called the core voltage offset and it's
exactly what it sounds like it just
takes the stock core voltage of your CPU
and applies an offset now since we're
under vaulting we're going to be
applying a negative offset and I
recommend starting with an offset of
negative 50 millivolts to get things
started and all CPU should be able to
handle this with no issues also make
sure that the core voltage is set to
default and not some static value and
this will allow the CPU to use a dynamic
voltage rather than a static and a Const
one so hit apply and go ahead and stress
test the CPU with the new V core in
action you should notice a drop in
temperature right away but we're not
done just yet
keep decreasing that core voltage offset
by around ten millivolts at the time
until these stress test crashes
indicating that the CPU is unstable when
that happens you should have a pretty
good idea of what the lowest stable v
core offset is for your CPU and for our
i five 8400 that was - 140 millivolts
with this officer the i5 8400 dropped
twelve point four degrees C in prime95
with an effective voltage of one point
zero two volts and this landed us at a
now very comfortable low temperature in
prime95 of seventy six point three
degrees C there is one problem though if
you restart your PC you'll notice that
the V coil offset is no longer effective
and annoyingly you'll have to reopen XTU
punch in the offset and hit apply to get
it going again there is a way that we
can set it to run automatically though
to make that V call offset enabled
whenever your PC is up and running the
first thing that you need to do is
create a PowerShell scripts or open the
PowerShell ISE and copy and paste the
script that I've left in the description
down below and full credits through
reddit user the big bug for showing this
in the surface subreddit the script
checks to see if the Intel XTU software
is running and then changes the ID 34
which is the core voltage offset with
the value in millivolts after V in the
default script that you'll find down
below it changes the value to 100
millivolts but just change this value to
the stable offset that you discovered
earlier and for hours that was 140 next
save the script to a location where it
won't get deleted and here I followed
the big bugs instructions to create a
separate folder in the boot drive called
startup next we need to get task
scheduler to actually open the Intel X 2
software in the background and run the
script whenever your system is running
so click create task give it a name
check run where the user is logged in or
not run with highest privileges and
configure for Windows 10 next go to the
triggers tab and create a new trigger
which starts the task on startup hit OK
and then go to the actions tab now and
this is where we're going to tell the
task to open Intel's XTU software so
click new make sure the action is set to
start a program and then in program
slash script
enter powershell DXE in the add
arguments field copy and paste the
arguments that I've also left down at
the description and are again thanks to
Reddit user the beat bug this is going
to open PowerShell in the hidden mode
and run the scripts that we saved
earlier double check to make sure the
path matches the path of your script
otherwise it won't run lastly head over
to the Settings tab and make sure all
the following boxes are checked hit OK
and to your password and your scheduled
tasks should be good to go
restart your system and double check
that your vehicle off set is still
effective you can check this in a
software like Hardware monitor under the
parameter ia offset if it's not
effective though double check that your
paths and conditions are all correct so
guys I hope you found this helpful and
if you've under volted you'll see if you
let me know down in the comment section
below I find this really helpful for
those who are running you know
power-hungry CPUs in small form-factor
systems with you know limited CPU call
Heights and things like that and as
we've looked at today it's really
effective for those who otherwise have
fairly power-hungry you know I 5s and i7
and are running the stock core as always
guys a huge thanks for watching don't
forget to subscribe if you haven't
already and I'll see you all in the next
one
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