ANTONY LEATHER’S
Customised PC
Case mods, tools, techniques, water-cooling gear
andeverything to do with PC modding
MODDING / OPINION
Puttinga
waterblockona
RadeonRX 5700
XTcanknock
38°Coffthecore
temperatureat
peakloadIsit worthwater-coolingNavi?
O
ver on p102 you’ll find a guide
to installing a waterblock on
AMD’s latest Navi cards,
which is likely going to be a popular
decision for Navi cards, despite their
sub-£400 prices. I certainly wouldn’t
want to sit next to the blower cooler of
the RX 5700 XT for long periods of time,
but as there are plenty of reference
models around, buying one and water-
cooling it is easy. However, there are
other benefits to water-cooling your
hardware other than noise reduction.
Processors are becoming more
intelligent in the way they boost
frequencies and respond to your
cooling system’s capabilities, adding
extra megahertz to their clock speed if
temperatures are kept below certain
levels, or maintaining a higher boost
frequency for longer. This is true for
CPUs as well as graphics cards, and
Navi is no exception.
As well as the GPU core, the
waterblock I used in the guide covers
the VRMs, memory and various
other small hotspots on the PCB,
plus it has a passive backplate. I
set about seeing just how much
cooler the RX 5700 XT ran when it
was water-cooled, compared with
using the stock cooler, while also
monitoring its boosting frequencies.
To start, the stock cooler hit 82°C
in AMD’s Radeon Settings WattMan
section during a ten-minute stress
test at standard fan speed settings,
with a peak boost frequency of
1930MHz. The software also reported
that the card was drawing 169W of
power. I then used a 240mm radiator
with two 120mm fans spinning at
1,000rpm, along with an EKWB D5
pump and reservoir as the cooling
system, plus EKWB’s EK-Vector
Radeon RX 5700 XT D-RGB Special
Edition waterblock.
After the same stress test, the
software showed an increase in peak
power draw to 190W, along with a
noticeably higher peak clock speed
boost. This figure rose from 1930MHz
at stock speed to 2007MHz once
water-cooled – a handy 77MHzhigher. The memory speed also
ramped up further, hitting 982MHz
compared to 872MHz at stock speed.
The GPU temperature fell massively
too, down to just 44°C at the end of the
stress test.
With boost frequencies being
responsible for a great deal of the peak
performance of modern hardware, it’s
useful to identify any metrics that the
hardware uses to determine those
frequencies, as well as whether there’s
any way to manipulate them, such as
boosting cooling.
Even if you don’t plan to overclock
your graphics card, AMD’s RX
5700-series cards respond well to
water cooling, with significantly higher
boost frequencies being observed. In
fact, the 2007MHz I saw with my
reference card is similar to many pre-