z 820 rebooting

[Tortoise420]

Dear Support,

I have installed two RTX 2080 TI GPUs in HP z820.

Its power supply was kept in mind as 1100 watts. Since there is second GPU installed, as soon as I put load on GPUs, it reboots the machine. Can you guide me how to handle the situation and how to use two GPUs without restart, 

OS is CentOS 7.5. 

it has two E5-2640 Intel Xeon.

Ram is 64 GB. 

Please your kind help and suggestions are awaited. I want to use two gpus on this machine.

[DGroves]

the z820 optional 1200 watt supply uses a multi rail type pwr supply, as such it's possible to overload the GPU rail while being under the total wattage requirement

your pwr supply has 3 GPU 6 pin connectors, with two of them being on the same rail, and the third on a seperate GPU rail

make sure your video card is using BOTH GPU power rails and not just the single rail with the two gpu connectors

you want GPU-1 and GPU-3 as i recall

next, cheap no name 6 to 8 pin converters are a poor choice due to it possibly using thinner wire and substandard connectors

but a 6 to 8 pin adapter from a name brand and not a no name amazonbasics one

the above is for one video card,..... the z820 system/supply IS NOT RATED FOR TWO OF THESE CARDS as installing two of them will overload the GPU power rail as you have found out

[Tortoise420]

This means, 

GPU1 should be connected with two GPU rail power.  with 6 to 8 pin converter

GPU 3 has 1GPU rail power and from where better it can get the remaining power?

or in either case this is not possible to use the second GPU on this board?  i mean both GeForce RTX 2080 ti on board?

Please your helping solution will ease my way on this machine. 

[DGroves]

ONLY ONE VIDEO CARD IS SUPPORTED due to power constraints (the 2080 TI draws 280 watts)

the single card should be powered by BOTH GPU RAILS if using the 1200 watt supply which has dual gpu power rails

use GPU-1 and GPU-3 connectors each are on different power rails (each connector is marked)

do not use GPU-1 and GPU-2 connectors, both are on the same power rail

[Tortoise420]

OK. I understood.  

Than guide me another way. 

1) combination of 2080 ti and 1650 can work? or that will also fail ?

2) and single 2080 Ti in HP xw 8400  can work?

[DGroves]

no-1 will work the 1650 draws only around 70-80 watts you should be able to also use up to a 2060 which is a 160 watt card but that's pushing it to the limit

the xw8400 is not a suitable system for a 2080 TI as the card will be bottlenecked by the older systems cpu/memory speed

in other words the card will not reach 2080 speeds, rather the slower 2060 speed which will be quite a waste

[Brian1965 · Accepted solution]

[EDIT - IMPORTANT!!!  -  Please note the HP Zx20 workstations do NOT support SLI as used in gaming, the second GPU card can only be used as an additional compute card, (providing your software specifically supports multiple GPU's and/or compute cards), or for additional video outputs, (e.g. multi-monitor set-ups)].

Hi Tortoise420,

According to the HP Z820 Maintenance and Service Guide the Z820 supports either 2x 300W GPU's, or 3x 225W GPU's;

This guide has a detailed section on how to install and configure multiple GPU cards in the Z820. I would recommend you download and study this document, (pages 92 & 93 - you must use specific slots based on the GPU's power requirements), e.g.

Also, as DGroves pointed out, it is very important that you use good quality cables. G1, G2 and G3 are on different power rails;

The HP Z820 power supply auxilliary PCIe power cables should be identified as G1, G2 and G3. Connect the G1 plug in to one of the 8-pin sockets on the first RTX card and connect the G2 plug in to one of the 8-pin sockets on the second RTX card - you will need two 6-pin to 8-pin auxiliary power cable adapters.

Use a 6-pin to 2off, 8-pin auxiliary adapter cable to split the power from the G3 plug to the vacant 8-pin sockets on each of the RTX cards.

Do you have any other PCIe cards installed apart from the GPU card(s)?

[Tortoise420]

Dear Respected Brain. 

Thank you so much. You made my day. 

trillions of thank you. apparently the load has been accepted by machine. If there is any more problem, I will ask for the help. 

Thank you again. 

Stay healthy always. 

Greetings.