HP Z840 Refusing to boot with RTX 3080ti

[izools1986]

So the good old Z840 being picky with GPUs issue.

BIOS updated to latest version 2.61

Removed all add in cards except GPU

Secure Boot disabled

RTX 3080ti (which I've tested in another machine, it's fine) triggers the six beeps and no display on boot issue.

Install an old AMD RX470 instead, with no BIOS changes, boots fine.

There's clearly something the system doesn't like about this 3080ti (which is fully functional) but I don't know what BIOS settings I'd need to change, or if I need to use a different card, how can I be confident it's gonna work (without going for a Quadro)?

[NonSequitur777]

@izools1986,

Welcome to our HP Community forum!

First of all, an RTX 3080 Ti should be perfectly compatible with an HP Z840 Workstation as this User shows: https://www.userbenchmark.com/UserRun/54950066.

Now, an RTX 3080 Ti has a hefty 350-watt TDP, and most models require three (3) 8-pin PCIe power cables and requires at least a 750-watt power supply. Your HP Z840 Workstation is powered by an 850-watt or a 1125-watt power supply, so in theory even the 850-watt PSU should have sufficient juice to power your graphics card.

Please explain how you hooked the RTX 3080 Ti to your power supply, because your GPU issue could be explained suffering from insufficient power.  These cards require three separate PCIe power rails, each providing 12V x 18A = 216-watt of power.

Kind Regards,

NonSequitur777

[SDH]

NS777,

You may have the answer in your post above. If the video card really demands 3 separate graphics supplemental power cables the 850W HP power supply version only provides 2. The HP 1125W power supply provides 4:

Only two graphics supplemental PCIe circuits...

versus:

1125Wversion provides 4 separate graphics power circuits instead

I just checked eBay here in US... best price for the 1125W version is 65.00 USD including shipping to US. The ZX40 workstation parts have really come down due to them coming off lease and being parted out. I've installed used HP workstation power supplies from eBay in the past as needed and never had even one go bad later.

[NonSequitur777]

@SDH,

Thank you -Yes, an outstanding observation: if the OP doesn't have the 1125-watt power supply, the OP should seriously consider this.

At least based on my experience with Z4xx and in extension Z8xx power supplies, the PCIe power cables are all 6-pin, thus the OP will also have to purchase 6-pin to 8-pin PCIe power adapter cables.  You can do this sans any worries since each PCIe power cable as I mentioned can provide up to 216-watt of power.

You can purchase a 1125-watt power supply under $65 via eBay: https://www.ebay.com/sch/i.html?_nkw=1125+HP+Z840+power+supply&_sacat=0&_from=R40&_trksid=p2553889.m....

And you can buy the 6-pin to 8-pin PCIe power adapter cables (HP p/n: 721859-001) also via eBay under $9 each: https://www.ebay.com/itm/135593828377?_skw=HP+721859-001&epid=24023795596&itmmeta=01K27XW6VSVA86R4D9....

Kind Regards,

NonSequitur777 aka NS777