GPU under 9.5 inches for Dell Optiplex 7010MT

Anything from the GTX 1660 Super and up will outperform the RX 580. The somewhat older GTX 1060 6GB is roughly equivalent to the RX 580.  GTX 1660 super is 229 mm about 9.0” long. I presume you had updated psu b/c you were attempting RX580 which requires a psu upgrade to have 6 pins:

GTX 1060 is typically 9.8” although some may be 9.5” long https://www.dell.com/en-us/shop/pny-geforce-gtx-1060-cg-edition-graphics-card-gf-gtx-1060-6-gb-gddr5-pcie-30-x16-dvi-hdmi-3-x-displayport/apd/a9204199/graphic-video-cards

ASUS Aorus RX580 is 232 mm 9.1”

https://www.aorus.com/graphics-cards/GV-RX580AORUS-8GD-rev-10-11/Specification

Your MSI RX580 is 269mm.

Always check the spec of card model to get precise length.  Different card makers make different card length.

@redxps630​ Is it possible to vertical mount the GPU so the connectors aren't in the way? I already removed the drive cage, so that isn't a problem

They do make PCIe extenders if you want the GPU outside of the case.

Since you tried an RX 580, I presume you have a higher-watt than stock PSU.  You'll need it for cards like the GTX 1060 and GTX 1660 SUPER.

Also, how would you plug into the GPU if it's mounted vertical inside the PC?

hardware guide suggests using low profile sata cable for the sata ports which hopefully can be plugged in underneath the long gpu.  USB3 port you can try the same, and if that is impossible, sacrifice the usb 3 (leave it disconnected) for the long gpu.

@redxps630​ When I leave the blue USB connector unplugged, it doesn't boot. 

edit: I don't know that for sure, but it was unplugged along with a loose stick of RAM, so that might have been the problem. The power button was also blinking three times during this. 

usb 3 disconnected may trigger a boot start up error.  there may be a way to use jumper to stop that error but I am not clear of the details.  how much clearance do you have between the long gpu and the usb3 port socket?

This one may help you. It is a right angled USB 3 motherboard adapter which will make a low profile connection. The 7010 MT FIO USB 3 cable connector is straight.

https://www.ebay.com/itm/172180586084?

That should fix it. The GPU was about a quarter of an inch from the actual connector on the motherboard, but the cable was blocking it.

@redxps630​ hi, it's been a while, but I just won an auction for this GPU: https://www.ebay.com/itm/126584488325 will this work?  I'm worried that the SATA port will still block it.

you can use 90 degree angled sata data cables to fix it.

the asus card is 9.5 x 5.1 x 1.5" it is borderline in length.  congrats in winning the card at a good price.  you will see if it fits when it arrives.  let the community know and upload a pic if you can

@redxps630​ I have a 90-degree angled SATA cable, but only on one side, can I use the 90-degree side on the motherboard?

yes you can use the angled connector on the motherboard side.  there are right and left angled ones.  the angle may cover adjacent port depending on how and which port you plug in.

for example this red angle plugged in the black port would not block the blue port next to it.

@redxps630​ Hi, it's been a very long time, but I received the card, and the metal on the bottom of the card it being prevented from being slotted in because it's hitting the motherboard. Is there a way to fix this?

can you send a pic showing which metal part of the card is causing issue?

@redxps630 ​