ddr3 vs. ddr4 and will my cpu bottleneck crossfired RX 580s?

[mw1122]

I would like to save some money by using my old ddr3 1600mhz ram 16gb but don't know if that will affect my pc's ability to mine effectively. I know most of it's on the GPU but I don't want there to be any sort of bottleneck. Would an I5 4690 bottleneck two RX 580s that are mining? does anyone else have a similar rig or questions?

[MATHReX]

If you are GPU Mining, then there is seriously no bottleneck with any CPU or RAM type.
My 10 GPU Rig runs on G4400 CPU (Dual Core CPU) and 4GB DDR4 RAM and I have had no problems as such.
So your CPU and 16 GB RAM is actually overkill for mining but I am thinking it is your gaming rig.
Anyway, Crossfire will affect your hashrate, I'll suggest disabling it and setting Compute Mode to Workload in Radeon settings before starting to mine.

[rdluffy]

No bottleneck, I used to have some rigs with old Athlons 

You can even underclock/undervolt your cpu to consume less energy
And forget about crossfire, you just need to activate compute mode, do the overclock or make a bios mod, there is a lot of content of how to do on youtube and here on BitcoinTalk

[Johny101010]

I would like to save some money by using my old ddr3 1600mhz ram 16gb but don't know if that will affect my pc's ability to mine effectively. I know most of it's on the GPU but I don't want there to be any sort of bottleneck. Would an I5 4690 bottleneck two RX 580s that are mining? does anyone else have a similar rig or questions?

No. Don't worry about anything other than optimizing your gpu's. I'm running a 10 rx580/480 rig with the cheapest Celeron I could find and 4gig of ram I found in a yard sale.

[Ken_terrance]

You don't have to worry ,use any one you can get your hands on either ddr3 or ddr4 ,I have rigs using both and 5-6 rx580 running in both so you are fine

[mw1122]

Thank you guys for the fast responses I really appreciate it! Have a safe weekend!

[nc50lc]

And FYI, you don't need to "crossfire" the two GPUs to be able to mine. That's only multi-GPU support for games and graphics.

When mining, each GPU works independently.
Your selected mining software will do the job for you.