Best bang for buck card(s)?

[Remuz]

So I'm building myself a new PC and I'm looking to repurpose my old rig into a dedicated hashing system.

I'm looking for a few GPU's to stick in it, preferably 3 or so. My budget is around $6-700 USD. I don't particularly mind 2nd hand cards. 

From my initial googling the reference 970 looks like my best bet.

What card(s) would you guys recommend I get?

[royce]

Just throwing some ideas out there:

If cost of electricity is not a concern, agreed about 970s. They're going on eBay for around $200-$220, so 3 of those would be a good fit. (And I wouldn't go older or smaller). But for the same price, a single new 1080 (when in regular stock) is close to 2 used 980 Tis or 3 used 970s. If electricity matters, a single 1080 is more attractive. A 1080 will probably also be supported longer by NVIDIA, but that's a ways out.

These links may be useful for comparing performance:

https://gist.github.com/epixoip
https://docs.google.com/spreadsheets/d/1...SsYEqOoqco

Double-check my work with your own research (on price and performance), but back of my napkin, for MD5, stock clocks, theoretical max watts:

970 SC: 10.8 GH/s, 170W (SCs are factory overclocked a little), ~3 for your budget = 32.4 GH/s, 510W
980 Ti: 16 GH/s, 250W for most, almost 2 for your budget = 32 GH/s, 500W
1080: 25 GH/s, 180W for most, 1 for your budget = 25 GH/s, 180W

In practice, power consumption will be a little lower. You'll also probably be able to overclock them a bit. And with fewer cards, you have room to add another later without having to pull one and sell it.

Hope that helps!

[Remuz]

Just throwing some ideas out there:

If cost of electricity is not a concern, agreed about 970s. They're going on eBay for around $200-$220, so 3 of those would be a good fit. (And I wouldn't go older or smaller). But for the same price, a single new 1080 (when in regular stock) is close to 2 used 980 Tis or 3 used 970s. If electricity matters, a single 1080 is more attractive. A 1080 will probably also be supported longer by NVIDIA, but that's a ways out.

These links may be useful for comparing performance:

https://gist.github.com/epixoip
https://docs.google.com/spreadsheets/d/1...SsYEqOoqco

Double-check my work with your own research (on price and performance), but back of my napkin, for MD5, stock clocks, theoretical max watts:

970 SC: 10.8 GH/s, 170W (SCs are factory overclocked a little), ~3 for your budget = 32.4 GH/s, 510W
980 Ti: 16 GH/s, 250W for most, almost 2 for your budget = 32 GH/s, 500W
1080: 25 GH/s, 180W for most, 1 for your budget = 25 GH/s, 180W

In practice, power consumption will be a little lower. You'll also probably be able to overclock them a bit. And with fewer cards, you have room to add another later without having to pull one and sell it.

Hope that helps!

How would you compare the 970 SC to the R9 290X ?
They seem to be more reliably available a bit cheaper each and they seem to perform similar. Power around here is very cheap, so it's not a worry and they won't be running 24/7 365 (yet).

[royce]

The numbers that I posted, plus the Google doc, should let you compare R9 290X with 970 SC. I prefer NVIDIA over AMD, even with a slightly lower speed, but YMMV.