I have been promising a ram overclocking
guide for seemingly forever so I've got
the Kingston HyperX blue 4 gig kit of
ddr3 memory on my test bench today in
addition to that I do have a hyper X Ram
fan which I did an unboxing of a while
back I found it to be extremely high
quality I really liked the look of it
overall and the other relevant things
that I have today on my test bench are
our core i7 at 875 K unlocked CPU so
that's what's going on under the hood
over here and then I'm using a p7 p55 de
premium motherboard in case you are
wondering so the first thing we're going
to do today is we're going to get
everything set up for a baseline reading
so that means I've got my CPU set up at
stock frequency and I've actually turned
off turbo mode so we are just going to
be running it at pure stock frequency
this is going to allow us to see exactly
what impact just changing the memory has
on an otherwise completely stable
baseline system okay the other thing
that I've done is I've enabled the XMP
profile for this memory so that goes
ahead and changes all the memory timings
for me isn't that handy make sure you
buy memory with XMP if you don't want to
fuss around with all this stuff so it
goes ahead changes the frequency to 1600
megahertz changes the timings to 999 27
these are your primary timings the most
important one is this one right here
that is the cast CAS latency so here
this frequency that is the speed of the
memory so that's how how fast it cycles
around these ones are the delay so
higher this and lower this is always
better one N or one T or two n or two T
that's a secondary timing that does have
an impact on performance as well and
then these voltages that it's dialed in
for me 1.65 that's the memory voltage
and one-point-three that is the voltage
of the integrated memory controller on
the CPU you should be aware that with
core i7 and Core i5 CPUs you should
never go over one point six five volts
on the memory because you can damage the
memory controller that is built into the
CPU so we're going to go ahead take some
baseline readings and then we're going
to come back and play around with some
of these settings a little bit and see
how much more
moments we can squeeze out of this
memory now that we've got the RAM dialed
into our stock XMP overclocked profile
you can see here all of these settings
are correct and CPU is running at its
stock frequency we're just going to take
a couple of benchmarks as a baseline
here so SuperPi is a popular memory
benchmark because what it does is it
gives you probably the largest possible
separation between like my mute setting
basically it's it's a very very fine way
of measuring the the performance of the
CPU and RAM and it'll give you
differences that you otherwise wouldn't
be able to measure so you can figure out
if what you're doing is beneficial or
not so you can see we calculated PI to 1
million decimal places and we end up
with a result of zooming in so I can see
oh no that's not right calculate 1
million decimal places it's going to be
the wrong one here so now click to start
ok and let's find out what we get this
time and we're going to take a quick 3d
mark reading as well and then we're
going to come back to these benchmarks
once we've played around with the
frequency latencies of the memory and
we're going to see how much we are able
to improve our system performance so
there that is the real value it is a
fourteen point three oh five seconds
alright so we're going to run 3d mark
and then I'll be back in a minute once
that's done so there you have it our
baseline 3d mark oh six reading is 18
five three four so one 18,000 534 3d
marks it should also be noted I am
running these benchmarks with turbo mode
disabled on the CPU so it is running
only at the default CPU multiplier of 22
X it is not scaling up when I run
intensive benchmarks this is just to
isolate the RAM as the performance
variable that we're looking at today so
the first thing we're going to try today
is leaving our timings at default
leaving all the voltage is the same
because we don't really want it that's
outside the scope of this particular
video we don't want to tinker around
with those and what we're going to go
ahead and do is take
the cpu ratio turn it down so we're
still very close to the two point nine
to six
target CPU frequency and then we're
going to turn up the base clock now
turning up the base clock is going to
give us a bit of a boost at equal
frequency on the CPU and then it's also
going to give us at the same ddr3 speed
so but I'm going to go ahead so 146 is
where I'm headed
so 133 is stock you can see at 133 the
options I have are all of your standard
ddr3 speed options but as soon as I go
up to 146 that's 1600 megahertz option
turns into 1750 so we're going to go
ahead and see if we can boot up at these
speeds and if we're stable and what kind
of performance impact that's going to
make okay I've done some tinkering
around and staying within the same CPU
frequency range so about 2.9 3 gigahertz
I have found that the highest I was able
to go was by lowering the CPU ratio to
17 X and increasing the base clock to
172 so this gives us a ddr3 speed of 2.0
6 4 gigahertz Ram was stable at this
speed so we're going to take some more
benchmarks and we're going to find out
what we gained by increasing the memory
speed to 2 gigahertz now one thing that
I do want to point out is that you do
not have to run the CPU at stock speed
in fact there's probably more benefit to
overclocking the RAM when you're running
an overclocked CPU because the CPU needs
more data to keep it fed but the reason
that I did it this way is because what
you'd normally do is find your max CPU
frequency in this case I'm pretending my
max CPU frequency is stock speed so you
find your max CPU frequency and then you
tune the RAM from there so once you by
the time you're tuning Ram you're
already trying to stay within kind of a
fixed range of CPU frequencies so we'll
go ahead fire up cpz fire up SuperPi so
you can see that we're running our CPU
at stock speed our run is now running
substantially faster this is one half of
the actual data rate because it is DDR
Class of memory so we're running start
to calculate to 1 million decimal places
so here we are we've seen a 25% increase
in RAM speed and let's see how much of a
speed increase we will gain from that so
fourteen point two two seven is our new
SuperPi fourteen point two two seven is
our new SuperPi score and then we'll go
ahead and have a look at the 3dmark
score in a moment so we end up with a
score of eighteen thousand six hundred
and ninety two which is a slight boost
over what we were recording as our
baseline although it's pretty much
within the margin of error so the
overclocking method that we use today
was just increasing the RAM frequency we
found it didn't have much of an impact
but look at it this way you buy the
HyperX blue and obviously your results
may vary you can get upwards of a 25%
increase in speed over what it's
actually rated for which even if it only
gives you like a 1% increase in a couple
of the programs you use it is a free
increase nonetheless so we're going to
see how low we can go with latency
overclocking and see if we can get some
bigger boosts that way stay tuned for
more by simply adjusting the latencies
we were able to go from 9 9 9 27 Layton
sees all the way down to 777 20 when you
consider the cost difference between
kits that are otherwise basically
identical so you look at kits like this
where it's a four gig kit 2x2 gigabyte
ddr3 1600 and NCL 9 vs CL 8 and you see
upwards of a $20 price Delta well it
starts to make like an overclocking
friendly kit like the blue that we're
using today look like a pretty good
value if you can get all of that extra
Headroom out of it so let's have a look
at our super Buy calculation for our c7
overclocking in this case latency
reduction more than like increasing the
clock speed overclocking so it's a
little bit different ok so we see a
score of 14 point no I missed it ok
we'll try again
I apologize for that I guess I couldn't
dear II have just turned off the camera
and gone back and read it but um I
didn't think of that until now and the
cameras been running selling might as
well roll with it okay so fourteen point
two nine that seems a little bit higher
two nine zero okay so I'll run my 3dmark
benchmark and then I will be back in a
moment okay well at 18650 4 3 D marks we
don't see a huge performance difference
between our stock 9 9 9 27 timings and
our tightened up 7 7 7 20 timings but
this has been my ddr3 overclocking guide
I mean if especially if you're done
overclocking your CPU because that's
where you'll see some big performance
gains and you want to tinker with it a
little bit more I highly encourage you
to go ahead try overclocking your memory
don't forget to do stability checks
though all along the way when you're
doing any overclocking and bear in mind
of course that my results today are not
necessarily reproducible if you buy the
same Ram I was lucky enough to get a 25%
overclock in terms of frequency or a
significant uh to speed grade bump down
in latency so improvement in latency but
you may not have the same results so the
best way well not the best way but the
way that I use to to check if memory is
stable is I use prime95 blend I use our
custom one and then I go ahead and let
it use all or most of the memory I have
installed in the system so as long as
this doesn't crash over a period of 8 to
12 hours you can assume that your RAM is
pretty much stable and then that way
even if it's only a small improvement
you can have some performance
improvements so thank you for checking
out my guide don't forget to subscribe
to Linus tech tips as well as NCI XCOM
for all of my videos
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