I need a 500W+ PSU that will fit in my case (Optiplex 780 DT)

[charbleach]

I need a 500W+ PSU that will fit in my case. I had a EVGA 600W PSU, which did not fit in my case by a few centimeters. I am using a Dell Optiplex 780 Desktop. The case has been described as ATX but doesn't seem like it. The standard PSU does not even come close to fitting the needs of my new video card. Thank you!

 

[Mark RM]

Did you measure the dimensions in mm of the one that's in it? That would be pretty helpful.

 

[william p]

It's a Micro BTX Desktop motherboard. The Mini Towers take ATX PSUs. the Desktops and smaller are proprietary. I doubt that you really need a 500W PSU. That MB only supports 95W CPUs, and there are only a couple bays, and expansion slots. It wont take a large 2 slot 2 fan GPU either. What video card are you trying to put in there? It has to be low profile also. a built out Opti 780 DT basically has a Q9650 CPU, 16GB DDR3 1333, some kind of SSD, and a GTX1050TI 4GB low profile videocard. Even that will require some modding to fit. The standard PSU will run all of that. An older PSU from an Optiplex 745 DT that supported Pentium D CPUs might have more watts. Seasonic makes some 350W units. TFX350, and TFX350GT with 6 pin PCIe. The 400W Athenas are bogus.Not as good as the original. i don't mean to discourage you. I would love to see you build a firebreathing Opti 780. But there are a lot of things that have to happen first before you need a 500W PSU.

 

[charbleach]

Did you measure the dimensions in mm of the one that's in it? That would be pretty helpful.

It's a Micro BTX Desktop motherboard. The Mini Towers take ATX PSUs. the Desktops and smaller are proprietary. I doubt that you really need a 500W PSU. That MB only supports 95W CPUs, and there are only a couple bays, and expansion slots. It wont take a large 2 slot 2 fan GPU either. What video card are you trying to put in there? It has to be low profile also. a built out Opti 780 DT basically has a Q9650 CPU, 16GB DDR3 1333, some kind of SSD, and a GTX1050TI 4GB low profile videocard. Even that will require some modding to fit. The standard PSU will run all of that. An older PSU from an Optiplex 745 DT that supported Pentium D CPUs might have more watts. Seasonic makes some 350W units. TFX350, and TFX350GT with 6 pin PCIe. The 400W Athenas are bogus.Not as good as the original. i don't mean to discourage you. I would love to see you build a firebreathing Opti 780. But there are a lot of things that have to happen first before you need a 500W PSU.

125mmx90mm

I am putting a XFX Single Slot Radeon R7 Low Profile (4GB) in the PC. The box isn't always right, but it says that minimal specs are a 400W Power Supply. I also am working with 6 Gigs of RAM and an E8400. Not the best CPU but it pulls through.

 

[Mark RM]

R7 240? You don't need a PSU upgrade for that card. Promise.

I mean it's close on the 255W PSU and I'd actually get the GT 740 as it uses less power and is 50% faster.

 

[charbleach]

Mark RM sorry for the down vote D:, misclicked there. Are you sure a 235W PSU can handle that? I still do want to play it safe.

 

[Mark RM]

I don't mind, downvote away , I just come to help people during the holidays, up or down is just a random number on some computer somewhere.

Actually I totally changed my mind, not because of the PSU but because I was looking at the manual for the MT not the DT, the slot won't support 75W power draw on the DT.

It's max power draw should be silk screened right under the slot itself on a Dell. It might be 25W

 

[charbleach]

Sorry for bugging you about your comment, but what max power draw are we talking about, the PCIE slot? Will this potentially render my GPU useless if the power draw is too much?

 

[Mark RM]

It will potentially render the whole PC useless (literally, not figuratively) if you plug in a card that draws too much power from the slot yes.

Look at the motherboard, look for something like 25W, 40W, 65W right at the pcie slot area.

 

[william p]

The 2 core is a 65W CPU, and the video card is what 30W? 750Ti would be a much better choice. 65W +65W =130W still no problem.
Look around on the GPU hierarchy chart. GT740 DDR5, GT1030, GTX750Ti are all better. Even 30W GT730 outscores it.
http://www.tomshardware.com/reviews/gpu-hierarchy,4388.html
Since you don't need a PSU maybe spend alittle more on the video card.

 

[charbleach]

Mark, there appears to be no number under the slot or around it at all.

 

[charbleach]

But, it is x16 which means it should top out at 75W

 

[Mark RM]

That's actually good news.
OK I confirmed the following, people have in fact run cards in the DT model up to 75W. on the existing PSU

Your PSU has a single 12v rail that puts up 18 amps (216Watts).

I also confirmed the PCIe slot is not a restricted wattage.

So you are left with any PCie half height single slot card that
a)draws less than 75W
b)supports Legacy BIOS

So exactly what is your card model number, lets go look and see if it support Legacy BIOS. Or just plug it in and see if it boots.

 

[charbleach]

The Model Number should be R7-240A-4NFR

 

[charbleach]

I think the card is UEFI, which should mean it would work with my BIOS. I don't want to try it just yet though.

 

[william p]

Opti 780 is UEFI. Dell was a developer of UEFI so they adopted it early.

 

[Mark RM]

yeah if it's the right rev of BIOS, sure.

n/m you're good, all the DDR 3 machines had UEFI.

why don't you want to try it?

 

[charbleach]

Just the worry of blowing my components. I know that's a low possibility but who knows.

 

[charbleach]

Are there any New Micro BTX PSUs that are above 350Watts? I know you guys just told me that I don't need a new PSU, but I want to play it safe and get a new one regardless.

 

[Mark RM]

There is literally no PSU I am aware of that will fit the Dell specialized dimensions except Dell. It's really not even a standard BTX supply.

 

[charbleach]

They are really pricy too. I'll keep looking but in the meantime can I put the GPU in without worrying about anything?

 

[charbleach]

Also if I decide to abandon this project, what PCs use DDR3L-1600 RAM? Sorry for the question.

 

[william p]

The Dell Mini Towers take ATX PSUs. In fact the 24 pin connector came from BTX. But the DT, and smaller are all proprietary. If you really want to be hard core about it, you can get an ATX PSU and run it behind the computer like a super wall wart. The wires should be long enough.
The GPU will be fine. The low PSU rating is because of the 95W CPU limit, and the small number of expansion slots and bays. There just isn't much you could connect to that PSU if you wanted to. Couldn't overload it if you tried.