[SOLVED] Optiplex 780 + gtx 1050 very unstable

[dakotadriggers132]

I recently bought a dell optiplex 780 (core 2 duo e8400, 2×2gb ddr3, 120gb ssd, 450 watt psu) with the intention of putting a gtx 1050 in it, and when I installed one (gigabyte windforce oc) it had become extremely instable, to the point of being unusable. If I launch any type of game it'll crash within ten minutes, and it's very likely to crash just doing basic web browsing. If I remove the card and use the integrated graphics it works just fine, what could be the cause? Also I had to use a pcie riser cable to get the card to fit

 

[william p]

What size OPti case do you have? What brand and model PSU? What brand and model riser cable? Is the card a 1050 or a 1050TI? Specific video card part numer would help also.
4GB RAM isn't really enough but I don't think that would make it unstable. Frame freezes and slowdowns, but not unstable.
I'm running a GTX1060 3GB in an Optiplex 380, and had a 1050Ti on a stock Dell PSU. My guess is the PSU or riser cable are the problem. That's a BTX layout and very hard to fit video cards into.

 

[dakotadriggers132]

It's a mid tower, its got an insignia 450w psu, the card is a base 1050, and the riser is an unbranded one I got for $10 off Amazon

 

[william p]

The Dell OEM PSU is a quality part and can run that card. The ZOTAC GTX1050 MINI drops right in an Optiplex MT with no mods.(ZOTAC1050Ti Mini also).
Some riser cables don't supply the 75W needed for the GPU. Other have a Molex to power them. I suspect the riser more than the PSU.
The Opti 780 is UEFI. A non UEFI GPU will require Secure Boot be disabled in BIOS, and Legacy Compatability Mode selected.The ZOTAC is not UEFI.
Booting into Safe Mode and removing the old GPU drivers, then doing a clean install is almost always needed.
http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=71
https://www.hardwareinsights.com/dell-h305p-01-power-supply-review/

 

[dakotadriggers132]

My card needs a six pin plug, so I can't use the oem psu. I'll definitely try replacing the riser cable and disabling secure boot to see if that makes any difference