PSU question

I was thinking of doing half a new PC, IE case, PSU, motherboard, GPU. My PC seems to be acting up less, and was thinking of just getting a new GPU, and do the rest later.

I have a mini ATX tower, Dell thats a couple years old? Looks like a Mid tower just not as tall. The PSU is 450. I was looking to get a GTX 770. I think I watched a newegg video on one of the 770s and they said you need a minimum 5-600 watt PSU. May have been a overclocked card though. The one Im looking says needs 250 watts...One other page said 230 on PC parts picker ><

Looks like my CPU a I5-2400 quad core 3.1GHZ needs about 95 watts+250=345watts so 105 watts to spare. Other then that 2 hard drives, CD/DVD I never use, and minor things plugged into USB ports like a camera, PS3 controller, and a small charging dock for an electronic lock box key for work. Most of that stuff not even on, or idle states.

So I would maybe be pushing the 450 PSU near its max? Is 250 the maximum load on the GPU? Is that safe to use the 450 PSU with a GTX 770?

Looking at this card http://www.newegg.com/Product/Product.aspx?Item=N82E16814500303&nm_mc=AFC-C8Junction&cm_mmc=AFC-C8Junction-_-na-_-na-_-na&cm_sp=&AID=10446076&PID=3938566&SID=

Had been looking at this PSU for the half a new build, but rather not spend an extra 100 if I dont need to right now. https://pcpartpicker.com/part/cooler-master-power-supply-rs650amaag1

Then saw this one https://pcpartpicker.com/part/raidmax-power-supply-rx700acb But wondering why that one is so dirt fucking cheap. Less efficient, but its still way below others on cost which worries me. Any thoughts on that thing? Never bought or installed a PSU before so....

This seems like a decent inexpensive 600W PSU. You generally don't want to get a dirt cheap no-name PSU because it might fail or just catch on fire.

A regular 770 doesn't consume more than 230 watt's at most.

The reason they said 5-600 minimum is partly because they have to guard against bogus advertised power supplies. ( potentially including your own )But also because margin doesn't hurt.
The graphics card and CPU, along with most other components take their juice from the 12 volt rail.Some power supplies have a total delivery of 600 watt simultaneously, but only 400 of those are from the 12 volt.

Others actually deliver the full load and then some on the 12 volt rail.
Check your PSU sticker for exactly how much your power-supply claims that it can deliver on that rail.

Your math is sound, but even if you have 450 on the 12volt, I'd probably feel that it 100 watt is borderline too close for comfort.

If you have a Dell, your existing PSU may not even have the required free 6 and 8 pin PCIE power connectors. Beyond that, the case may not even be able to accept an aftermarket PSU at all. If it even will fit, the motherboard in that Dell may require a proprietary connector that the aftermarket PSU won't have.

Seen this situation happen countless times with people wanting to put high end GPU's in their inexpensive or older off the shelf PC's, with Dell especially.

I always get 700 or 750 watt PSU. Unless you're trying to penny pinch there's no reason to make a big deal out of it. 600 is probably enough for your needs. Never go minimum, though (400 or 450w).

What MB said is also a major thing you need to consider, though. Your tower size and your mobo would determine what PSU (among other parts) you can even use.

That's just my thoughts, though.

@mb: the dells i've seen are often those weird BTX cases with power supply on the top and the L-angle cables for the hard drives, so it's hard to get the straight plugs to fit in, at least without mashing them in a way i'm not comfortable with. also the 24 pin depending on the PSU may have trouble reaching where it needs to go in those cases.

ugh, prebuilts...

This is pretty much how I feel. There's no real point in buying something that just barely cuts it and leaving yourself no room to grow. You'd end up wasting a bunch of money if you ended up upgrading again down the line. They seem to be one of the cheaper bits of the whole building a machine anyway, might as well get a decent one.

Actually, I kind of feel the same about a case. I bought a full tower for the machine I'm currently building. I'm just building a bare essentials machine right now, but I want to give myself plenty of room to grow. With a decent tower and a good PSU, I don't have to feel limited next year when I want to push just a little more out of my games.

Cool, thank you for the input. Sounds like I should just do the half build then, So I dont run into issues. Hopefully it will go well. Ive installed CD drives/Hard drives, GPUs, memory sticks. Never done a CPU, motherboard and PSU before.