JULY 2019 PCWorld 93and relatively painless hit, given that it’s still
the equal of a x8 PCIe 3.0 connection.
PCIE 4.0 WILL RUN HOT
Heat will be a challenge for PCIe 4.0. With
the move from PCIe 2.0 to PCIe 3.0, a
considerable amount of performance was
squeezed out of it by increasing the efficiency
of the protocol. With PCIe 3.0 to PCIe 4.0,
most of the performance comes from
increased clock rate, which brings more
heat—so much that the fancy heat sinks aren’t
just fashion statements, but necessity to
maintain performance.
The chipset to supply the PCIe 4.0 is
hotter, too. Vendors tell us it’ll generate
anywhere from 11 watts (at idle, most likely) to
16 watts of heat. It’s hot enough that just
about every PCIe 4.0 motherboard we’ve
seen featured a fan for the chipset. Fans on
southbridge chips were actually fairly
common just 10 years ago as well.
This is a consideration but likely not a
concern. Fans do add to system noise, but if
done properly, you’ll be hard-pressed to
hear it.PCIE 4.0 IS NOT
BACKWARD-COMPATIBLE
Initially, AMD fans were juiced to hear that
PCIe 4.0 compatibility could be done on
older x470 motherboards. In fact, Gigabyte
released a UEFI update that appeared to
show an older x470 going from PCIe 3.0
to PCIe 4.0.
AMD officially dumped a bucket of cold
water on that idea. “PCIe 4.0 will not be
supported on motherboards released prior to
the X570, so 400-series
and 300-series will have
PCIe 3.0 support,” an
AMD spokesperson told
PCWorld. “These boards
were designed and built
prior to the capability to
ensure PCIe 4.0
functionality, and we
cannot adequately ensure
a performant, stable user
experience. We do not
believe this is an
acceptable experience for
our consumers.”One Reddit user had high hopes after a Gigabyte BIOS/UEFI update
seemed to enable PCIe 4.0 support on older AMD motherboards.