S7 or s9

[Jigor]

Should i add another s7 or save up for a s9?

[aakashsangwan]

If you refer to this link on 99bitcoins.com
https://99bitcoins.com/2016-bitcoin-mining-hardware-comparison/

Here is a comparison between s7 and s9 and you can clearly see that s9 is the winner and as far as I know you should always check the Joule per GHs rating of miner, whichever is low is more power efficient and will use less electricity per GH.
So my advise is to save money for s9.
Although I'm a newbie in mining.

[SA Bitcoin Brothers]

Should i add another s7 or save up for a s9?

It depends. If you have cheap power. S7s go for cheap secondhand. But if your electricity is expensive, go for S9

[sidehack]

And depending on the specific model of S7 there are different ways of going about it, but they can usually be made to run more efficiently or at a much higher hashrate. Sometimes 4TH/1KW for $200 beats out, at least in the short term.

[Jigor]

my power is 9.5 cents per kw

[leowonderful]

my power is 9.5 cents per kw

Definitely S9 then. It's a little on the high side but if you were to add an S7 you would hardly be making anything. I wouldn't even touch the S7 at all at that price, instead I would really be looking at altcoin mining as profit margins are usually higher. It's still possible with an S9, though.

[DoomDumas]

Should i add another s7 or save up for a s9?

Is the S9 are the one from Bitmain with few backdoor ??

I so, I'll never buy one !

[NotFuzzyWarm]

Should i add another s7 or save up for a s9?

Is the S9 are the one from Bitmain with few backdoor ??
I so, I'll never buy one !

After all the kerfuffle about that (never activared) code it has been entirely removed by Bitmain. Introduced in the 1st s7's it was for folks to have remote-access to their miners via the Cloud but the service was never implemented.

[swogerino]

Should i add another s7 or save up for a s9?

Is the S9 are the one from Bitmain with few backdoor ??

I so, I'll never buy one !

It is fixed in the latest firmware from Bitmain so there is not anymore any backdoor. At least this is what Bitmain claims and the community has not reported anything wrong for the time being so I guess they have really fixed it.

OP, S9 is the perfect choice for your energy cost as with the S7 you will lose more money than you will invest.