I’ve not tested it because I don’t have a rift yet. I suppose it will be powerful enough. I hope so haha!
The biggest limitation imo is the power supply. It’s an external brick of 330w. Putting a gtx 980 was a bit risky but it works. I had to remove a small fan to make it fit tho. I also removed the HDD and replaced it with an SSD and I removed the DVD also. Need to maximize the power consumption to allow the gtx 980 to ‘‘breathe’’. Some people have made some mods to allow the use of an external psu just to power the gpu separately but it makes the machine a bit less portable! The gpu tray doesn’t really allow gpu longer than 10.5 inches. That’s why I had to remove a fan to make it fit hehe!
Of course, there is not much room for Over clocking.
Motherboard is custom so it’s not really possible to upgrade it. Currently the gtx 980 is the strongest gpu that is possible to put in the x51. Hopefully, in the future, gpus are going to be smaller and less power hungry otherwise I’m going to have to stick with it for a while!
You could check out other small form factor desktop pc like the digital storm. It’s bigger than the x51 but less limited. It’s also more expensive. Asus Rog g20 is similar to the x51 too!
but currently it’s my setup and I like it.
16 Gb ram ( I think the limit is 32 in my x51)
EVGA gtx 980 superclocked
SSD 240 gb + SSD 120 GB