GPU: XFX Vega 64 Air
CPU: i5 4690k @ 4.5Ghz
Motherboard: Gigabyte Z97 Gaming 3
PSU: EVGA Supernova B2 750W
RAM: 16GB Kingston 1600 DDR3
I get crashes unless I set a -20% power limit. The screen freezes for a few seconds, goes black for a few more until the driver recovers. temps hit 75c on at any voltage stock fan profile but my ambient temps are pretty high (I'm Australian), and the card has ample airflow. setting a custom fan profile will make to card top out at about 63c, still crashing.
I have noticed some weird readings from GPU-Z, namely a spike in power usage up to a ridiculous 1800w, but I this happens even with my power setting at -20. At stock settings I may even get crashes on the desktop, they are rarer but they do occur.
really hope I don't need a better PSU to run this, it's been an excellent PSU for the few years I've had it, and handled my power hungry R9 290 just fine.
Regarding the power supply, seems fine.
Blower style vega 64 is known to run hot without setting a high fan rpm. Maybe you could try undervolting - also see if there's been a bios update for it. You can use gpu-z to see what bios it has.
If you got the board second hand, it might have mining bios on it - if it has a bios switch, try the other bios first.
There have been issues with power supplies being incompatible with Vega due to their insane power consumption, so it is possible the same kind of thing is happening to you, if you are sure that the +12v supply of your unit is not dropping below 11.9v.
Thank you for your responses, I've got a little more information and an update:
Update: just had 6 crashes in a few minutes booting into windows, yay for me. the power limit was in place as well.
The Card is second hand and was used with stock bios and an undervolt for 9 months (was run with on a corsair 1200w)
The Crashes happens on both BOIS, and GPU-Z reports both as stock XFX vega 64 air (I don't think you can mod Vega bios due to AMD locking it down).I haven't tried updating bois, and I'm not comfortable doing so, but I think that the "updated bios" available might just be for a newer batch of chips as this is a day one Vega card. I have tried undervolting (p6 at 950, p7 at 1050, both 1582 offset) but my issue in games seems to be tied to the power limit, or at least the clocks I run without it engaged (pretty much anything over 1200).
Unless Vega's power spikes are supposed to be this crazy, I see no reason to doubt the power supply, as it's running well within it's limits (stock clock with undervolt reaches a high of 170w on the core) I also don't know how I could check my PSU rail voltage fluctuation without power-couplers, and that's a bit too far out of my league when it comes to testing PC harware.
XFX has responded to my concerns with the answer of "try it in another PCI-E slot, if that doesn't work return it to your retailer" welp, guess I'll try? I'm going to try contact the retailer as I was able to get that from XFX's Website. any other suggestions in the meantime are appreciated, thanks.
Ouch, second hand Vega 64...Means it was quite likely used for cryptocurrency mining with an altered BIOS that was run 24/7 until it became unprofitable, then reflashed with the "original" BIOS and sold.
The updated VBIOS is for Vega II, not Vega 56/64, and adds UEFI support to a small batch of cards which shipped without it.
You can monitor voltages using AIDA64, HWiNFO64, or Gigabyte's motherboard software.
I have issues with my new vega 56's, I have two.
by the looks of wattman, the default clock speed at p7 is above the clock rating for the card I have, its 1620mhz in wattman, but the cards supposed to do 1520mhz.
please check those clocks to see if it might be the same issue.