Live data from Hacker News

Intel 8th Gen Core with Radeon RX Vega GPU Presentation

videocardz.com

11–20 of 29 posts

Re: Intel 8th Gen Core with Radeon RX Vega GPU Presentation

#13
post #9
post #6

Only 8x PCI-E 3.0? That's a little on the low side for a regular card, not to mention chips on the same interposer, no?

It's enough. Even top end discrete cards can't saturate 16x PCI-E 3

I guess I'd like to see much tighter integration between the two chips so that we don't have to write code that avoids the PCI bus at all costs. Today you fit your entire working set into VRAM and don't touch it from the CPU, so it's sort of hard to say "it's not a deal we don't saturate the bus anyway" when that's only because we bend over backwards to not touch the bus in the first place.

Re: Intel 8th Gen Core with Radeon RX Vega GPU Presentation

#15
post #9

Earlier quoted context omitted.

It's enough. Even top end discrete cards can't saturate 16x PCI-E 3

I guess I'd like to see much tighter integration between the two chips so that we don't have to write code that avoids the PCI bus at all costs. Today you fit your entire working set into VRAM and don't touch it from the CPU, so it's sort of hard to say "it's not a deal we don't saturate the bus anyway" when that's only because we bend over backwards to not touch the bus in the first place.

Isn't that the kind of optimizations that you can only make for consoles, where you know that all users have the same hardware?

Re: Intel 8th Gen Core with Radeon RX Vega GPU Presentation

#16
post #9

Earlier quoted context omitted.

It's enough. Even top end discrete cards can't saturate 16x PCI-E 3

I guess I'd like to see much tighter integration between the two chips so that we don't have to write code that avoids the PCI bus at all costs. Today you fit your entire working set into VRAM and don't touch it from the CPU, so it's sort of hard to say "it's not a deal we don't saturate the bus anyway" when that's only because we bend over backwards to not touch the bus in the first place.

I would imagine that they took the best GPU chip they could afford the space and power for, and found that 8 channels was enough for 99% of their customers?

I assume adding more channels takes space, perhaps the GPU would have had to be lower performance to add more channels?

(speculating)

Re: Intel 8th Gen Core with Radeon RX Vega GPU Presentation

#19
post #6

Only 8x PCI-E 3.0? That's a little on the low side for a regular card, not to mention chips on the same interposer, no?

AFAICT, Coffee Lake has 24 PCI-E lanes, 8 of which are used to connect to the chipset. If they used all remaining 16 for the GPU, then NVMe and thunderbolt connections would have to go through the south bridge, affecting latency and throughput.

Re: Intel 8th Gen Core with Radeon RX Vega GPU Presentation

#20

Earlier quoted context omitted.

I guess I'd like to see much tighter integration between the two chips so that we don't have to write code that avoids the PCI bus at all costs. Today you fit your entire working set into VRAM and don't touch it from the CPU, so it's sort of hard to say "it's not a deal we don't saturate the bus anyway" when that's only because we bend over backwards to not touch the bus in the first place.

Isn't that the kind of optimizations that you can only make for consoles, where you know that all users have the same hardware?

No, modern GPU APIs give you plenty of control over data layout, and it's the model AMD had been pimping for a while with their 'HSA' push.
Post reply on HN