Dell 3260 pci e slot

Compact model is relatively low-power PC with 240W PSU max,
(high-performance options sacrificed to get a smaller size),
they even had to mount chipset on another side of a board to win some space
(and x16 slot would have to be much longer),
you can't fit it with high-processing power PCIe device which would require high bandwidth,
x8 PCIe is more than sufficient to drive NVidia T1000 PCIe Gen3
(I think via W680 chipset, not CPU-bound lines)
without having bandwidth bottlenecks
(it doesn't need x16 Gen3 but would need x16 for older Gen2 PCIe).

Hi there. Thanks very much for the explanation. Ive got an nvidia A2000 in mine but not had the chance to use it yet as im waiting for ram to run up a VM (using it as a ProxMox hypervisor) it appears to be working as it is drawing power.

Good to know thanks...ive got the thinner of the 2 psu's so i might pick up one of the higher capacity ones. Many thanks.

A2000 does work with x4 PCIe Gen4 slot without problems,
it consumes 70W (temp peaks to 80W), W680 chipset has Gen4 PCIe.

you need up to 75W for other system components with Precision 3260 (without CPU)
TDP for i9-12900 is 65W, peaks to 200W on high-end systems
(capped on this machine lower, you will hit thermal throttling before reaching power limit anyways)

70W+75W is 145W, plus 65W for CPU (CPU/GPU peaks are probably 95% uncorrelated).

If machine is supplied with 180W PSU brick - this might lead to instabilities on heavy workloads.

Dell' second option with 240W power supply is highly recommended if you have extra GPU.

P.S. If you manage to fit A2000 in there without issues (it does accept some dual-slot PCIe cards, just has to be low profile short version) - then be careful if you're using too thick old-school 2.5'' SATA drive with this machine (not M.2) as it will probably significantly block airflow on a suction-side of NVidia A2000 card (e.g. some enterprise versions of 2.5'' drives are much thicker than standard consumer ones).