what's going on YouTube J's two cents
here one point out it's J's two cents
not J two cent or JZ two cents it's just
James two cents I mean why is that so
hard but we are fast approaching the
warm months of summer and some climates
get super freakin hot and that's when I
notice a lot of questions come my way
about very specific things when it comes
to water cooling so this summer we're
going to try and touch on all of that
we're going to rehash some old topics
and we're going to do something that
I've never actually done on this channel
we are going to talk about pump speed
and does it matter today we're just
going to perform a test here on skunk
works and we're gonna see what happens
in my scenario when it comes to pump
speed I thought it'd be fun but before
we start playing with our pumps let's go
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inevitably what happens every time we
talk about radiators water pumps and
water cooling and computers is people
want to compare it to things like
automotive cooling when it comes to
radiators and thermostats and water
pumps and the thing is you can't
directly compare that you're talking
about very low temperatures here very
low pressures whereas in a car you're
dealing with huge delta temperatures
between ambient temp and the coolant
temp reaching you know over two hundred
and twenty degrees fahrenheit in many
conditions obviously our coolant here
isn't getting anywhere near that hot so
you really can't compare the two it just
isn't directly comparable so inevitably
happens is you you start to hear things
on forms along the lines of well if you
run your pump too slow the coolant is
going to move too slow through the loop
and the coolant is going to touch the
block too long and it's going to get
really hot so if you really
about that the flipside would be so the
coolant is going to stay in the radiator
longer and cool off more so on the flip
side though the other side of the
argument is well if your pumps moving
too fast then the coolant is moving
through the radiator too quickly and
it's not going to cool down fast enough
now pretty much both of those scenarios
are true in the sense of when they talk
about the timing of fluid flow where yes
it's going to sit in the blocks a little
bit longer it's going to hopefully pick
up some heat but it's going to sit in
the radiator longer as well if you run
it really fast it's going to make more
passes per minutes a crummy Oh what if
you were to say be able to track this
one molecule right inside the loop in
time how many times it went around the
entire loop per minute yeah there would
be more times per minute which is going
to mean it's going to run through the
radiator more and in the end of the day
running it slower or running it faster
tends to give you about the same result
and that's what I'm going to hopefully
show you guys here today hopefully
physics aren't going to change suddenly
and I'm going to be making out to look
like a liar and even if that's true it
will stay in the video because this
again is all about facts here I like to
deal with facts they're they're fun to
deal with actually you can't really
change those so here's what we're going
to do right now I'm going to load up
Heaven benchmark on my 3-way Titan X
water loop which gets really hot it's
running a d5 it's independent from the
CPU so there's actually no contamination
of temperature between anything
happening with the CPU and the V RMS and
the GPU so this actually can be a pretty
control to test here now it's three
tight nexus with a 560 radiator and a
280 radiator running a 250 millimeter
reservoir and then again as I said a
variable speed d5 that's a manual
control not a PWM so I'm actually going
to control it I'm going to do a control
here where I let the test run for about
10 minutes in heaven let the heat get
but nice and built up in the system and
then we're going to log what the max
temperature was and then I'm going to
let the system completely idle for about
a half hour I'm going to cool off the
room open the windows let the hot air
get out of here and start all over from
the same ambient temp and then we're
going to pump the move the speed of the
pump to a hundred percent and we're
going to compare the results and see
exactly what happened so I'm gonna go
ahead and do that now and then we'll
come back we'll talk about the results
well for me it'll be a while but for you
it'll be like right now just so you know
what you guys are looking at this is
what we care about right
here these are the three tight necks as
you can see 35 32 and 35 they're running
a bit warmer at idle because I do have
the three panels hooked up so they do go
up a little bit higher on their base
clock as you can see right there encore
clock they're running at a thousand
megahertz right now so they're not
ramped down to idle that's why the
temperature a little warmer so we don't
really care about the minimum we care
about the maximum which is right now 35
C so I'm gonna go ahead and run heav'n
benchmark and then we're going to see
like I said after the system gets full
fully heated up and the settings on here
we're going to push it we've got it
running a 34 40 by 1440p panel
tessellation I'm going to go ahead and
put that on extreme and then
anti-aliasing I'm leading at 2x before I
start the test one other thing I'm going
to do here is I'm going to take fan
speed out of the equation I don't want
it speeding up and slowing down so I've
set my fans static to 70% inside a speed
fan so that's our constant right now the
only thing we want changing is going to
be the actual speed of the pump we don't
want the load to change on the software
and we don't want the fan speed to
change because that can obviously impact
our results
so here's the first result right here
63c was the hottest GPU temp as you can
see the loads were pretty consistent
temperatures had stabilized they weren't
still going up so that was our max
temperature 63 which might lead you to
go wow that's really hot for
water-cooled card yeah it actually
really is and obviously the pump is
running really really slow so what we're
going to do now is I'm going to go ahead
let the system completely cool off as
you can see it's taken a little while to
come down water-cooled systems take time
for the temperature to drop we're going
to pump that we're going to rent that
pump up to 100% and then we're going to
see exactly what we get after that
alright so there's the new result 56c
that came down from what 63 so that's 7c
difference by just changing the pump
speed yeah obviously there's a reason
why that happens so let's go ahead and
talk about that because that's the thing
a lot of people leave out is there's a
lot of variables that lead to these
temperature fluctuations all right so
let's talk here about what just happened
some people might look at this
conclusion and go oh that's it that's a
set conclusion across the board higher
pump speed equals lower temp done ship
it doesn't really work that way guys you
have to understand in my system it's a
bit of an extreme situation here
where I am trying to get as far on one
end of the spectrum as I can and as far
as I can on the can on the other end of
the spectrum to see what the measurable
difference is and then and between that
white of a gap I only saw seven
differences I'm not going to say seven
is a bad number seven is actually a very
very good number when it comes to
temperature difference between just
changing the pump speed but remember in
my system I've got three Titan X's that
are running in a parallel config which
means each one of those cards is only
getting 1/3 of the flow rate entering
through this tube right here so it's
going to divide between all three cards
and then it's going to recollect as it
leaves all three cards and go back to
the pump so really my pumps being at max
speed right here means that my cards are
only getting a third of that max speed
if that makes sense so the reason why
the temperatures were so high when I had
the pump set to zero or and zero
actually being the lowest setting it
doesn't mean off it's because one third
of the lowest flow rate of this d5 with
a 560 radiator and three blocks and
another 280 radiator on the back and
then of course all of the fittings and
bends meant that the flow rate going
through these three GPUs was very very
low probably just a trickle level of low
so what was happening is the fluid
wasn't moving fast enough to actually
cool off the graphics cards effectively
or efficiently so when I said in the
beginning was one of the arguments is if
the pump is moving too slow then the
coolant sits there too long and gets too
hot it doesn't pull the heat out of a
GPU fast enough is partially true now
again remember this situation I'm
talking about here specifically because
of my 3-way parallel config now most of
the time you're not going to see a huge
prints in temperatures between lowest
setting and highest setting in a single
GPU and even a double or sli GPU
configuration or crossfire depending
what you're running because of the fact
that you're not going to see as much of
a flow drop-off again my loop here
having multiple radiators and three GPUs
is a lot of resistance for d5 to have to
overcome so if I had only had one or two
cards in here I would have expected the
results to be a little bit more narrow
and not as big of a difference there now
one thing to keep in mind though is when
you run water cooling pumps at their max
speed they tend to get pretty noisy so
there's going to be a trade-off there
where you're going to really have to
think about you know is the noise factor
of running a pump at max speed D fives
aren't too bad believe it or not and
mines actually isolated with rubber
mounts so it's not really transferring
vibration to the case or the desk can't
feel the case with my hand right next to
it right here some pumps actually will
create vibrations that just resonate and
sound terrible
DBC pumps are perfect example a DDC pump
at max speed is incredibly loud so
you're going to want to keep that in
mind as well but if you guys are
struggling with higher temps and you
would like in your loop and you've got
your pump running a lower speed try
finding a sweet spot where the noise and
the performance is going to help you but
ultimately I wouldn't look at pump speed
as being the kind of thing that is going
to make a huge difference when it comes
to the overall effectiveness of your
loop that's one of the reasons why i
don't run pwm pumps i like to have
manual control over those and i tend to
set it and forget it and i usually don't
have temperature issues now if you're
running a config with a multi speed pump
or variable speed pump once you sound
off in the comments and tell people what
your results have been that way you can
kind of get a collection of data down
there so people can learn from not just
my results but your results as well
remember on setups like this and yours
and other people's mileage is going to
vary not your mileage may vary your
mileage will vary anyway thanks for
watching today's video here again this
is not a conclusive like this can be
applied to all systems you're going to
have to play with yours you don't have
to play with yours and see exactly what
feels good if you know what I'm saying
but you're going to have to determine
for yourself what's best for your system
again ambient temperatures or in fact
airflow in the room was a factor as the
room heats up the loops going to get
hotter it doesn't just stay it's going
to be dependent on the air cooling the
radiators a lot of people forget room
ventilation is as important as you know
your case ventilation anyway time to go
guys thanks for watching today's video I
hope you've enjoyed hope you've learned
something and as always I will see you
in the next one
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