All pascal card must use the web driver, they are not supported by the Apple driver at all (nothing to display).
right, but goMac is having problems with a 680, which can use either the Apple driver, or the web driver, right?
All pascal card must use the web driver, they are not supported by the Apple driver at all (nothing to display).
I recall hearing a while back that Apple's Nvidia driver was problematic under High Sierra. Could the difference be that the 1080ti is using Nvidia's driver? Or, are you using the webdriver?
Yeah, to safely power any Vega card (so far) you need Pixlas mod or secondary PSU.
Yeah. Something is funny here. If Vega 56 is drawing mostly from the aux connectors it should still be ok-ish. It’s going to pull the Mac Pro out of reconmended spec but not out of design tolerance. On BIOS B it shouldn’t be pulling more than 90-ish watts from each aux connector. Again, out of Apple supported spec but not out of tolerance. (It seems Apple programmed the tolerance to be about 120.)
I’d have to plug in and take a look, but the only other explanation would be that either Vega 56 has a max much higher than we’re thinking, or the draw is uneven and pulling more than 120 on an aux connector.
Not sure yet how you’d rebalance that on dual 8 pins. You’d almost need a fully custom cable.
Or I could just draw from SATA bay power, or step down to a 580.
AMD is making good products but from a power efficiency standpoint they aren't there yet. There are AMD cards that are dual 8 pin that are only single 8 pin or even dual 6 pin on the nvidia equivalent side.
Even balanced by using 2 y-cables it could still pull too much and SATA bay power could be dangerous too. If you already have the card then just do the pixlas mod. It's not that difficult. You could get a Sapphire PULSE Radeon RX 580 and not worry about it, but it's about half as fast.
The strange thing about Vega 56 is it's efficient enough. It's actually more efficient than some of the Apple cares. It's just drawing power un-evenly.
I may plop mine in and figure out if one aux is being pulled more than another. But if they're being pulled evenly Vega 56, even without drawing much from the PCIe slot itself, should fit nicely inside 120w per aux connector.
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The trick here is I'm not sure you can balance with y cables. At least not with off the shelf cables. Normally you'd push both aux pins into an 8 pin connector but... If I'm actually pulling more than 75w that won't necessarily work. I'm basically trying to shove 1.5x the max load of a single 8 pin into a single 8 pin and that's not probably going to work.
If you could balance I'm pretty sure you wouldn't need the SATA power to begin with.
The issue is that it can draw spikes of power that are too much. The current draw that you can see it taking from like iStat menus is an average. The Vega 56 is a 64 that didn't quite make the cut in the manufacturing process. They were able to sell the slightly defective chips by disabling some of the compute units and downclocking it without changing anything else. To each their own, but I would not use the mini pci-e connectors on the logic board to power it.
Sure. The issue doesn't look like the max TDP though, especially on BIOS B. It looks like an issue with unbalanced draw on the aux power.
Definitely wouldn't be an issue, spikes and all, if Vega 56 would just draw more from slot power. What I'm reading online is that it seems like Vega only uses slot power for the blower.
From what I'm reading about GPUs on the Mac Pro in general, total power isn't usually a problem and the limit is definitely not 75w (it's not 150w either.) It's when a card is imbalanced and not evenly pulling power.
(The Vega 64 is still just no good though because even if you're willing to go beyond 75w the power draw is still just way too much. Especially if it draws, like 56, nothing from slot power.)
This is what I am interested to know as well. The Vega 56 should not pull more than the 1080Ti. And this is confirmed in almost all review. And if I can run Frumark on a 1080Ti with just the mini 6pin. The Vega 56 should able to do that as well. Unless the Vega 56 is programmed to draw almost no power from the slot, and nearly totally rely on the aux power. There is one report here about Furmark will shutdown the Mac straight away even with proper power management (balanced the load).
Since there is just one report, I really want to know more if any other user able to share the load between the mini 6pin and successfully run Furmark without any shutdown. Also, what's the power draw reading when doing it.
Well the difference again would be that Vega doesn't seem to really pull slot power, but puts almost it's full load on the aux connectors.
But even if the slot is only pulling 30w, aux should still be ok. It's more than 75w, but the Apple six pins aren't 75w six pins.
Oooooook. Just spent some time with Vega 56 on the internal connectors. Took some measurements. All measurements are from BIOS B, not A.
I ran Furmark for 10 mins. I know some people might want a longer test but I have to eat so I might run more later. Machine never shut down.
Max power draws according to iStat (approx):
PCI Booster A - 96w
PCI Booster B - 84w
PCI Slot - 25w
Never really moved.
I'm a Furmark newbie so I ran it at the default of 1280x720 because it's not frame capped. If there are better settings let me know.
Both those readings are higher than the 75w of a minimum spec 6 pin, but within known spec for Apple's cables/supply with the extra lead supplied.
A)get a bridge between the mini 6pins and the 8pins. You can just the EVGA PowerLink. Or as simple as dual mini 6pin -> single 8pin -> dual 6+2. No need to worry about overload the single 8pin. There are 3 12V wires inside, and each of them usually able to handle up to 10A. Which means up to 360W in total. You are far far away from that.
Still considering if I want to keep the card. If I do I'll get the aux sources balanced.
But without sleep and fan control, I'll still be waiting for good drivers. And by that time, Vega Nano might improve things again. And the resale prices on this are pretty good.
And the card is wicked fast, which is great, but I feel like it's wasted a bit if you don't have 4k (I don't on my Mac Pro).
At least a bunch of Metal bugs dropped off.
I'll trade you my RX 580 plus cash would make a nice addition to the hackStill considering if I want to keep the card.
This is interesting... Vega is already beating a 1080Ti in a game fully utilizing Metal 2:
http://barefeats.com/dirt_rally.html
Interesting to see once drivers are ready from the new iMac.
This is interesting... Vega is already beating a 1080Ti in a game fully utilizing Metal 2:
http://barefeats.com/dirt_rally.html
Interesting to see once drivers are ready from the new iMac.
The info at that page suggest that the game may be CPU limiting.