HP Z840 Power supply

[Sovy75]

Hi,

We bought a HP Z840 recently but we're a bit underwhelmed with the available power supply connections.

There's no 8-pin PCIe power cable, and only three PCIe 6-pin cables. Is there any way to have more of these?

[old_geekster]

@Sovy75, welcome to the forum.

Here is a 6-pin to 8-pin PCIe adapter that should work for you.  I suggest using their Chat Live option to talk to a Tech to make certain that it will work.

Please click the Thumbs up + button if I have helped you and click Accept as Solution if your problem is solved.

[Sovy75]

Thanks for the response and the welcome.

I'll be ordering the adapter. However, I'm still at a loss why there are only three six-pin adapters. The 840 service manual states that the Z840 can accomodate two 300W cards each. Those cards would usually require a 6-pin and an 8-pin, per card. Looks like I'll be needing a molex to PCIe adapter too when I order a second Titan X.

[old_geekster]

Thank you for the additional information, @Sovy75.

Since I am not an HP employee I can't answer your questions about why there aren't certain components.  Here is the information for the video cards:

Graphics cards
● PCIe Gen3 (PCIe3) bus speeds; can support three PCIe Gen3 graphics cards in PCIe3 x16 slots

● Up to one 150 W or two 75 W graphics cards with 850 W power supply

● Up to two 300 W or three 225 W graphics cards with optional 1125 W power supply (other configuration restrictions may be required)

It appears, however, that the two 300W video cards are with the optional 1125W power supply unit (PSU).

With the standard 850W PSU, only one 150W video card can be used.  The PCIe slots provide 75W of power each without an additional power dongle.

[SDH · Accepted solution]

There is a post in the forum here made about the Z620 power supplies and the designation on the power supply label specifying how much wattage can go through each 6-wire PCIe supplemental power cable.... they can carry significantly more than the ATX standard of 75 W each.  For high power video cards bought through HP for their workstations there are references to included splitters and converters that take a single 6-wire plug and convert it to two 6-wire plugs, and a single 6-wire plug and convert it to an 8-wire plug, respectively.

I'm sure the same applies to the Z840 power supplies.... they are built to standards well above ATX.  I have no idea how to get those converters individually from HP, however.

The link to that post is  HERE.

Note that there also is an added link in that post to HP documentation that mentions those adapters...... the HP power capacity for each of their 6-wire cables is much higher than you'd expect, as you'll see (18A x 12V = 216 watts each, from the Z620 power supply side sticker).

http://h30434.www3.hp.com/t5/Business-PCs-Workstations-and-Point-of-Sale-Systems/really-only-1-6pin-...

[Sovy75]

I put in a second Nvidia Titan X (Pascal edition) today, with the remaining 6-wire cable convert to an 8-wire plug and another molex to 6-wire plug, and it seems to run fine so far. So it looks like the Z840 is able to handle it.