OptiPlex 5070 SFF and upgrading PSU

Question

I am wondering what the highest possible PSU for this computer is. I have 30 of these machines in a lab and someone purchased, without my knowledge, 30 graphic cards that require a 400-watt PSU.

bradthetechnut · Accepted Answer

If your PC's came configured that way from Dell, they're fine and all is covered under warranty. The RX 550 is only a 50w card.

Spec sheet for the Optiplex 5070 can be Googled. Not linking it since I couldn't currently source it from the Dell site.

As configured from Dell, the 5070 SFF comes with 200w PSU. If in doubt, you can always double-check yours. It's the MT that comes with 260w PSU. 360w PSU redxps630 described as "Dell oem" comes from another model that also works for the 5070.

The RX 550 is one of the graphics options mentioned on the spec sheet. Screengrabs below, 3rd one showing PSU's. (90w PSU is for the micro.)

As for 400w PSU for a 50w card, that I don't know where it came from.

Aftermarket PSU's can be a different story than Dell PSU's. A PSU has various rails, or lines of power. Aftermarket PSU's often have less power on the 3.3v/5v rails than Dell, but boast more total power. So, a 400w aftermarket PSU might have more power on the 12v rails than a 305w Dell PSU, but still less on the 3.3v/5v rails than the Dell. GPU makers will always suggest/recommend a PSU wattage based on covering the bases in regards to aftermarket PSU's and possible PC configurations.

So, as long as your PC's came configured from Dell with RX 550's, then you can be confident the Dell PSU can power it and your PC. If the person that ordered the PC's also ordered the GPU's separate, and let's say the GPU's aren't on the spec sheet (or other Dell documentation), and/or wattages not within Dell specs, then we could be looking at something else.

Hopefully I eased up any confusion. That's fine if you still have questions.

It's also good that you questioned the GPU's. Older Dell specs did require higher wattages for certain GPU wattages.

redxps630 · Answer

Dell oem 360w psu is the top psu for 5070 SFF. when the graphic card says it requires a 400w psu, it is often exaggerated. the 360w psu is most likely sufficient.

8HKG7 360W Liteon Gold

19YR3 Chicony Gold

SolPlyr · Answer

That still won’t provide a buffer though, right? Even if the 400 is exaggerated, I’m still looking at the possibility of not having enough wattage for everything with room to spare.

redxps630 · Answer

the gpu for SFF is low profile and likely of low power. if you give the gpu model we can do an accurate calculation of power need in typical real world scenario. please include cpu and ram and ssd/hdd info as well. I presume your pc uses dvd too.

just to illustrate, assuming i7-9700, 4x8GB DDR4, SATA+Nvme SSD, DVD, and gpu is Nvidia GTX 1060 which has Nvidia "Minimum System Power Requirement 400 W", on line basic psu calculator shows Load Wattage:295 W
Recommended PSU Wattage:345 W

so for typical real world application, the optiplex 5070 would need no more than 300w from psu. A 360w psu gives enough buffer.

SolPlyr · Answer

The card that was purchased is the VisionTek Radeon RX550.

This PC is an Intel i7-8700 CPU, 16 GB RAM, no external drives, I'm assuming the HD is 256 GB (says 237 on the local drive). I'm not sure if it's a SSD or a HDD. I'm assuming HDD.

SolPlyr · Answer

It should also be noted that everything in the system came that way from Dell. We haven't added anything to it.

SolPlyr · Answer

So I'm confused now... why does the GPU say minimum 400 watt PSU? I would hate to purchase one and get it installed and then watch the computer fry because it didn't have enough wattage.

redxps630 · Answer

using the spec you provided, basic online psu calculator result here:

Load Wattage:236 W
Recommended PSU Wattage:286 W

A 360w psu gives you plenty of buffer.

the Dell default psu for 5070sff is 200w, which is too weak for RX550.

redxps630 · Answer

looks like brad has given you a thorough explanation. regarding your confusion, the 400w vendor psu requirement is often an overstatement in order to cover all possible pc configurations. prebuilt pc often needs less power. we still do not know the current psu rating of your sff. but no worries of "frying" because a too weak psu would just have the pc shut down, no damage done.

SolPlyr · Answer

RX 550 is not what came with the tower. It was purchased without my knowledge and sent to me. These are 4 GB cards and not 2GB.

We did open the computer and saw that the PSU is 200 watts, so we definitely know what is in the machine itself as far as that goes.

The packaging for the card says that it's a 4GB GDDR5, 4X mDP, supporting PCIe 3.0. So, I'm not sure if this is the same as the 4GB on the spec sheet that you showed me or if this is a completely different card.

bradthetechnut · Answer

Please see my above reply now that I'm done editing it. I needed to finish it on my desktop.

Could you please upload a photo of the PSU label?

Also, the last screengrab at the bottom mentions a 4GB dual Radeon RX 550. I believe "dual" means dual fan, also meaning it's larger. Yah, I checked on it. It comes in variations of dual fan and dual slot.

Thanks for uploading the box photos. I see now where you got "400w PSU" from. As far as I've been able to research, it's still only a 50w card.

bradthetechnut · Answer

More screengrabs:

The above is more Dell specs showing the RX 550 works with 5070 SFF.

I am going to give this the "however." However, running a 50w GPU on a 200w PSU has never made my recommendation list. Doesn't for sure mean not working if it's within Dell specs.

GPU's and CPU's don't always draw max power. It depends on what's being done on them.

If you don't feel comfortable running those RX 550's, I'd return them if you don't need them.

Also, as redxps 630 said, the wires or PSU won't fry. The Dell PSU will simply trip and shut down if over loaded. I specifically say "Dell PSU" because there are cheap, generic PSU's out there that are a danger regardless.

Please let us know if you have any more questions.

bradthetechnut

SolPlyr · Answer

This is what I have.

bradthetechnut · Answer

I'm going to let the PSU aficiando, @redxps630, answer that one. I can't see the whole thread right now, but I believe the 260w PSU for the MT works in the SFF due to the PSU having the same small form factor. 260w Dell PSU is plenty for a 50w card.

I can easily say that because a 275w PSU powering a 75w card is within Dell specs.

Optiplex Desktops

OptiPlex 5070 SFF and upgrading PSU

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