Why Radeon Vll dont support pci express 4.0 when lower priced X5700 does ?
Why doesnt a 20 yr old Ferrari ( that cost $500,000) have a touchscreen, when a Tesla ( that cost $80,000) have one?
Because the Vega II came out long before the RX 5700 and before the PCiE 4 standard was released. The new navi cards do not have a top tier card that replaces the top card of GCN yet. I am sure when they do it the replacement will support 4.0.
Well the Radeon VII is based on the same chip as the Radeon Instinct MI50 and that card was released last year and support
There's more to the card than just the GPU chip.
So you are comparing a professional grade GPU to a consumer grade one?
Yeah really helpful post!
According to Anandtech.
"Radeon VII also cuts back a bit on Vega 20’s off-chip I/O features. Though AMD hasn’t made a big deal of it up to now, Vega 20 is actually their first PCI-Express 4.0-capable GPU, and this functionality is enabled on the Radeon Instinct cards. However for Radeon VII, this isn’t being enabled, and the card is being limited to PCIe 3.0 speeds (so future Zen 2 buyers won’t quite have a PCIe 4.0 card to pair with their new CPU). Similarly, the external Infinity Fabric links for multi-GPU support have been disabled, so the Radeon VII will only be a solo act."
https://www.anandtech.com/print/13923/the-amd-radeon-vii-review
For what it is worth it really isn't an issue either way. None of these cards even saturate the bandwidth of PCiE 3 so 4 is just a new standard to support not a necessity by any means.