CMH vs LED

I was about to nab x4 315W CMH for a 5x10 tent, but now I'm questioning whether that's the best investment. I'm using every watt I have available in my house, (with some buffering) so I figure efficiency is gonna be key to increasing yields. With that in mind, what's going to yield the most? Cost isn't a huge issue as I don't need to buy everything yet, but I'm definitely interesting in saving money with DIYs.

I've used both, both are efficient and can be run around the same watt/sq. ft., both produce well. If you're ok with DIY though, COBs or the newer strips/QB style boards might fit better in that space and possibly cheaper. 4x 315's with hoods will give you about 7' x 7' coverage which doesn't lend itself as well as custom panels in the space you're using. That's one of the main reasons why I ended up switching to COBs in my room vs. CMH, the COBs allow me to utilize the space better and run about the same total wattage (including ballasts for the CMH) but with better coverage due to the size of the space I flower in.

1250/50 = 25... Im not saying you cant but that's kinda on the low end. I would look into the strips/qb route personally. I luv my 315 in the colder months.. but whenever i need a new lamp I will probably be wiring a qb

https://www.rollitup.org/t/diy-with-quantum-boards.927159/

CMH arent bad. they are fixed in efficeincy though.

you buy 4 CMH for x dollars and y watts and thats what you got
you buy LEDs for x dollars and your efficiency will be what it is. spend another 50% more or so upfront and youre efficiency will increase substantially

"what will yield more" is at least as much a function of your space, environment, strain, and skillset, as it does your choice of light