How can I work out mhash/s on new graphics cards?

[peterwilliamson]

Hi all

Is there a way of working this out for new graphics cards?  What attributes of the gpu affect the mhash/s rate?  Sorry if this seems like a dumb question but I'm going to buy a few cards this month and want to make sure I make the best buy.  I have never seen any gpu spec from a supplier that states the mhash/s rate.  Any advice will be very appreciated.  I'll post photos of my new miner when its bought and up and running

[buddrulez]

This website should give you a good idea!

https://en.bitcoin.it/wiki/Mining_hardware_comparison

[microxp]

bitcoin or litecoin?
the different coins requires different hardware..

[peterwilliamson]

Thanks for that microxp.  Are there any graphics cards that can do both? 

If so what would be the best premium card for either bitcoin, litecoin or feathercoin? I'm trying to find the best mhash to watt ratio.

I think lite or feather coins seems the most profitable to mine, but for now I'm synching my botcoin wallet so I'd test that 1st.  Currently my hash rate will be painfully low.  I'm at the stage of investigating, but if it works I'll start investing.

I'd also try some of the online get free bit coins sites, but I'm suspicious it could be a scam or virus ridden.  Has anyone used these?

Thanks also to buddruez.  I’ve seen this but how in date is it?  I don’t want to buy what I think is the best to find out for another $50 – 100 that I could have got something twice as good.

Thanks for all the help so far 

[ginjou]

bitcoin or litecoin?
the different coins requires different hardware..

Well, if you look at the charts, it's approximatily the same with cpu mining.
AMD HD 7XXX series are the best for mining efficiently:)

[ginjou]

I'd also try some of the online get free bit coins sites, but I'm suspicious it could be a scam or virus ridden.  Has anyone used these?

I'm using some in a daily basis, and it works fine, but those sites, called faucet, give a really low amount.
It's about some µBTC, don't hope to become rich with those, it's just like they give you some pennys

[peterwilliamson]

Thanks for that I’ll give the sites a go.  My housemate is worried I’ll cause our network problems!

So ideally, according to the chart, I’d be best off buying a 3 or 4 card setup of 7970’s to start with.  But do these work for bitcoin and litecoins?

I’m concerned to buy specifically for bitcoin mining if the asci machines arrive and make it exponentially harder for my new rig to make anything.  I’d love to get just a few bitcoins for the sake of it and then move to lite or feather coins. 

[kgains]

If so what would be the best premium card for either bitcoin, litecoin or feathercoin? I'm trying to find the best mhash to watt ratio.

That really depends on so many factors. Take a 7950, the power consumption while mining can easily vary from 180W or less to 250W+ with the core and memory overclocked like crazy. The secret of mining is to get a good ratio. There is no point pushing a card to, for example, to 1.3V if you only get 5% more hashes vs running at 1.1V or less. Because the extra voltage could use up 20% more power.

ATM, possibly the most efficient card is actually the 7790 (GCN 1.2) but while it's great to get 300MH/s with only 60-80W, that's not a great hashrate these days. Great hash/watt though.

[faraway]

I've tried with two HD7970, and I'm around 680W at 2x 750kH/s. However I've no way to check if the computing done by these board is reliable or not. Is there a cgminer test setup to check if this configuration if the computing done is exact?

[peterwilliamson]

Right thanks for that.  It may be worth losing a little on watt efficiency to get the superior hashrate.  Also need to find the right motherboard.  Apparently the best ones are the ones where the cards are sat further apart so the temperature is easier to control.   

I’m hoping to start with kit to produce around 2000mhash/s.  I know its costly upfront, but the returns should be better in the long run surely as the algorithms become harder to crack?

Once I’ve got the value in the 1st setup I’d buy more and maybe look to lite and feather coins.  What about a pair of 6990s at 850 watt and 1740mhash/s?  I presume if I doubled up and had 4 of these running on a motherboard I’d get 3400mhash/ps but a 1700w power draw.  Apparently on http://ltc.kattare.com/calc.php that would mean $13 a day.

Does this sound right?

Why don’t sellers specify the mhash/s rate on their technical specs?

[miningusa]

There are websites and wiki's to help you calculate this.

[peterwilliamson]

ANIMALPANCAKES thankyou.  Very imformative