30 PCWorld AUGUST 2019REVIEWS RYZEN^3000
DDR4/3600
performance and will
update it with
DDR4/3200 once time
permits. We are told by
AMD, however, that
DDR4/3200 CL14
should yield roughly
single-digit performance
differences compared to
DDR4/3600 CL15.
The other variable
here is storage. For the
Ryzen 7 and Core i9,
both were tested with
very fast MLC-based Samsung 960 Pro 512GB
SSDs at PCIe 3 Gen 3 speeds. The Ryzen 9
3900X, however, is the first CPU and platform
we’ve seen to support PCIe 4.0. Because it is
a key feature of the new platform, we used a
2TB Corsair MP600 PCIe 4.0 SSD plugged
directly into the CPU’s PCIe lanes. For the
tests we’re running, storage should not
impact CPU performance.TO MCE OR NOT?
For this review, as with our original Core
i9-9900K review (go.pcworld.com/i99k), we
were torn as to whether to enable the “multi-
core enhancement” feature. MCE is a
motherboard-enabled feature that runs Intel
“K” CPUs at higher clock speeds, while using
more power and producing more heat. What
offends some is that MCE is technically aviolation of the letter of Intel’s law and
considered an “overclock.”
You’d think that makes turning it off an
easy decision. The problem is, just about
every mid- to high-end Intel motherboard
implements MCE set to auto out of the box.
That means that any reviews of these new
CPUs with the feature explicitly set to off, is
not quite an honest portrayal of the true
nature of the Core i9-9900K’s speed that
most consumers will experience.
Leaving it on gets even stickier,
because every motherboard maker
implements it slightly differently. There’s
no easy way to draw an exact bead on
performance with MCE on.
In the end, our tests are all run with MCE
off on the Intel CPU, and AMD’s somewhat
similar Precision Boost Overdrive turned off asCorsair’s MP600 supports PCIe 4 on AMD’s new Ryzen 3000 CPUs.