I understand this as "long enough with the motherboard, without any similar issues."
Do you still keep these two old components to try and experiment cross-combination for a long enough period (core2 duo+gtx, core2 extreme+radeon)? If s.th. else has been changed, too (ram, etc) also recombine.
So we are talking about QX6800, not for the X6800, which 'd work normally, but the quad-cores seem to need the 710/720 version, not the 700 of the motherboard.
Just see this (copy-paste) from dell: " 2 ground ref. lines were missing from the 700 PCB board but added to the 710 to make it quad compatiable. "
Check these, though not from the sites I usually use:
https://www.dell.com/community/Desktops-General-Read-Only/XPS-700-Processor-Upgrade/td-p/3137827
How can I find out what the "top end" CPU would be for my Dell XPS 700? Right now I have a Intel Dual-Core 6400 running at 2.13GHz... I've seen reviews with much faster CPU's so I'm g...
www.dell.com
Update bios to latest version, if not already, but with your current motherboard it mb 'll not work normally if it is just 700.
https://www.dell.com/community/Desktops-General-Read-Only/XPS-700-BIOS-update/td-p/2471324
1.4.1 seems to be the latest version.
This GTX 1050 Ti version does not need a 6-pin connector...right?