Z800 Black Screen and Restart under load

[Makers2020]

Hi Guys,

I recently upgraded my GPU in my Z800 workstation to a EVGA 1080 SC from a GTX670. Since upgrading I have been experiencing a 'Black Screen' when under load such as gaming at 1440p. My previous card simply used the two 6 pin connectors  but my new card uses 1 8 pin connector. Originally I was using a single 6 pin to 8 pin adapter but that didn't work correctly and I experienced black screening all the time. I switched to a dual 6 pin to one 8 pin connector which certainly helped but I still get the issue. By tweaking the maximum power limit in MSI afterburner to 80% I was able to greatly reduce the frequency of these crashes at a cost to performance. I would like to be able to run this card with at least stock performance and I've turned to this forum due to finding very little information else where. I have the 850W PSU which I thought would be enough but maybe it isn't, I would also appreciate any information you have on the power rails as I'm clearly overloading something as there is no blue screen it simply just restarts.

System Specs:

HP Z800 Workstation

HP 850W PSU

2X Intel Xeon x5650's

1x EVGA 1080 SC

32 GB of DDR3 ECC Memory

400gb hdd

150gb ssd

[DGroves]

unless you have the optional 1115 watt power supply, using a 1080 overclocked card (200 watts) with the stock 850 watt supply is not really recommended depending on how/what hardware you have installed in your z800

read the z800 "HP service manual" from the HP site for more details on the z800 power related specs

http://h10032.www1.hp.com/ctg/Manual/c04490361

https://support.hp.com/us-en/product/hp-z800-workstation/3718645/manuals

the highest rated official HP nvidia video card was the quadro 6000 6GB model at 204 watts, and this was again only with the optional 1115 watt supply installed

[Makers2020]

Thanks for the fast response, that definitely seems like the issue. Rather than upgrading the Z800 PSU to the 1115 W PSU  I was thinking of running a second PSU just for the GPU. Is that advisable?

[DGroves]

several years ago there 5.25 bay "AUX" power supplies made but they were expensive and had quirks/issues

i strongly recommend just buying a 1115 watt z800 supply it works as intended and the cost is not that great considering it's wattage and availability on ebay