PCWorld – August 2019

AUGUST 2019 PCWorld 65

4.0 just for potential improvements to multi-

GPU gaming.

Update: The Radeon RX 5700 series only

supports DX12 and Vulkan’s explicit multi-GPU,

not CrossFire for DX9, DX10, or DX11, per

TechPowerUp (go.pcworld.com/12sp).

Virtually no game developers support explicit

multi-GPU in shipping games at this time.

But there are advantages to having the

Radeon RX 5700 and 5700XT ride the

bleeding-edge PCIe 4.0 interface. Herkelman

says a large percentage of gaming GPU

buyers also run content creation tasks, which

makes sense with Twitch and YouTube

engulfing the world. “There is much more of a

benefit in creative workloads today for that

new standard,” Herkelman told PCWorld.

I wasn’t able to validate the claim, as I

don’t have a PCIe 4.0–compatible system. To

tap into the Radeon RX 5700 series’ PCIe 4.0

than HBM2, whose pricing he called
“volatile.” The power-hungry Vega cards
needed HBM2’s energy efficiency, but AMD
says GDDR6 offers 60-percent-improved
performance per watt versus GDDR5.
Faster, more efficient clocks and faster,
more efficient memory both provide tangible
benefits to PC gamers. One of the flagship
features of the Radeon RX 5700 series, PCIe
4.0 support, doesn’t—at least in normal
gaming scenarios. Modern graphics cards
simply don’t saturate the PCIe 3.0 x16
interface typically used in most gaming PCs.
I’d wondered whether the move to PCIe 4.0
could benefit performance in CrossFire
setups, because those need to tap into a
narrower x8 connection. Herkelman said any
benefits would be “corner case, game-
dependent, and situational.” He said he
wouldn’t recommend people buy into PCIe