All indications point to Vega 20 silicon being much more than a 7 nm version of Vega 10. The new kernel has already been presented by Lisa Su at Computex 2018, showing some interesting improvements, which are now added to the alleged use of the PCI Express 4.0 interface.
Latest AMDGPU driver for Linux suggests that Vega 20 will support PCI-Express 4
Vega 20 will come with four HBM2 memory stacks, totalling 32 GB with a 4,096-bit interface, which will offer a bandwidth that doubles that of the current Radeon RX Vega Radeon, although we do not get excited since for now will not reach gaming.
A detailed inspection of the latest AMD GPU driver for Linux includes PCI-Express gen 4.0 link speed definitions, offering 256 Gbps of bandwidth per address in x16 bus width, twice the current PCI-Express Gen 3.0 specification. Vega 20 got its first indication of PCI-Express 4.0 support in a slide leak during the CES 2018.
Vega 20 will support PCI-Express 4.0
These slides suggested that in the second half of this year the first product based on Vega 20, a silicon that has already been announced, would be launched. They also indicated that the third generation of EPYC processors will come with PCI-Express gen 4.0, which could be an important novelty of the Zen 2 architecture.
We’ll have to wait a little longer to find out if Vega 20 finally includes PCI-Express Gen 4.0 support, which would be a major novelty in this first AMD GPU built at 7 nm. It is possible that the first products based on Vega 20 will be announced at the AMD event in July, and there is less to be said for this.