I have a Dell Optiplex 9020mt, and I upgraded the GPU from crossfire hd 8490s to a single r7 260x. The recommended PSU is 500w. It currently has a 290w. It doesn't have a 6 pin, so I'm running a 2x sata to 6 pin adapter. I've unplugged all superfluous devices, and I estimated about a 310w power draw peak, which it very rarely reaches. So I guess the question is, am I sitting on a time bomb? Is a catastrophic failure likely, or am I just going to shorten the lifespan of the PSU? A new PSU is on the horizon, this is just a stop gap, but I don't want to keep using my pc if I'm likely to cause damage to other components. I've got the following components drawing power: i7 4770 + stock cooler 2x 4gb & 2x 2gb Ddr3 1600mhz Seagate Barracuda 500gb R7 260x 2gb gddr5 Wireless kb/m Usb wifi adapter 1 80mm case fan
As capacitors age their power output can drop so potentially you might find the PC will power off. Worse case scenario the heat and wear causes something to blow sending a surge through components I've heard horror stories of using molex/stat power connectors to 6pin adaptors melting and causing fires as many are very cheaply made and aren't really designed to take the power draw of a GPU. I wouldn't put my faith in that solution https://outervision.com/power-supply-calculator https://www.bequiet.com/en/psucalculator https://seasonic.com/wattage-calculator# The links above can help you calculate your power usage and at a quick glance you are pushing close to 300W peak load. It's unlikely the power draw will damage components itself but it more likely it will cause the PSU to fail. That failure would more than likely damage something. I remember a few years ago noticing that Dell motherboards don't take the full power allocated to them (Running only the 24pin connector and no 4 or 6 pin supplemental power) yet were still able to run processors just fine, processors that should be using more power than what was provided. I never found out exactly why but surmised they are downclocking or have less aggressive turbo or manage to run incredibly close to the power limits. If it was me, I would get a new PSU sooner rather than later rather than running the risk, especially if it is a Dell PSU currently in there. You can pick up a decent 400W PSU for peanuts these days.
Assuming the 4770 is a non K the peak system pull is probably closer to 250w rather than 300+ with an average pull closer to 200w (unless you are running something that is pegging both the CPU and GPU at full load you shouldn't see peak load). I have based the above on the i7 having a TDP of 84w (can't be overclocked so this should be relatively accurate unlike the K series SKU's) and the GPU rated max of 115w (see below for links to both). The rest of the components you have listed will only pull a handful of watts. https://ark.intel.com/content/www/u...7-4770-processor-8m-cache-up-to-3-90-ghz.html https://www.techpowerup.com/gpu-specs/radeon-r7-260x.c2465 That said I don't know anything about the quality of the PSU in the system (does it have OCP for example) or the impact using the adaptor would have (@javaman has more detail above). In summary, assuming the PSU is decent then it should be able to provide the necessary power based on the components listed.
From my experiance of Dell PC's in the past their PSU's are cheap. Not garbage cheap, but think super budget options. So given its age I'd probably err on the side of caution and pick of a new fairly average PSU and swap it in. Especially as those cases have terrible cooling, so your PSU is half of it, and heat leads to increased aging!