Bitcoin Forum

hi
i wanted to build a scrypt mining rig. but with just 1 graphics card as i dont want to invest much right now.

can you suggest me which is the best graphics card (for the price) available on amazon.com and how much hash power should i expect.
also, after i get the card, what all will i need to get the rig mining? will i be able to do it or will i have to go to some computer shop?

thanks a lot!

Radeon outperforms Nvidia for mining and i've been told that the 7790's are a good price and mine enough for it to be worthwhile.

R9 270 has the best hash/watt ratio. You can get 450 hashes out of it if you know hoe to tweak. I am assuming you are talking about the new cards.

I am running a rig with 3* R9 280X Radeons... its a nice & hungry little machine :) --> 850 to 950 W/h

:)

I stay in a condo...so free electricity :-D
So power consumption doesn't matter!
Yes new cards, and I'm looking for the beat price per hash!

https://litecoin.info/Mining_hardware_comparison
You've probably seen this but this has all of the individual GPU model performances.  With Scrypt you'll typically see that the more GPU memory the more possible hashes.  To find the best possible dollar/hash amount you'd have to rely on that list for the k/hash and divide that number by the lowest price you can find the GPU at.  Then compile a list and look at the secondary variables: heating issues, power issues, manufacturer issues, etc. to determine the best buy.

I started mining recently, and tried out several cards, starting with Nvidia ones I used for folding...  No more folding for me :).  AMD/ATI cards beat Nvidia easily though, even A-series processor are better than mid-range NVidia.  To start small, look at 7700 series, 7790 needs one PCI-E external power plug, can still be had around $100 after rebates, and mines decently fast; however even 7850 gives nice hashing power bump (~50% faster) while still being budget friendly. HTH.

Using TomsHardware figures, the R9 280x consumes 255W, while the 7950 consumes 188W. Let's take something a bit less than the top figure from the mining comparison page, and you get, say, 780 kh/s for the R9 280x, and 700 for the 7950

700/188 = 3.72 kh/s/W
780/255 = 3.05 kh/s/W

So, if you accept the performance selections I chose, the 7950 is still the superior card (by a fair margin, I'd say). Of course, there are other factors, such as the limited number of cards you can get in a rig, and of course, the price. The R9 280x is a bit pricier, but it seems most people are shifting to the R9 280x because of the extra hashes per rig.

Hi,

I have actually quite good success with two very cheap Powercolor 7990s. They have a design power of <400W (specs, not measured by myself) and they consistently deliver 1300kH/s each in an open-bench setup. If you go this route, make sure you have a 750W PSU (that's enough to run one 7990 card).

I picked these up at Newegg for ~$600 each. I feel I got a good deal.

Another thing you might want to consider is the power efficiency of your PSU. It's quite often overlooked as these cost more, but gold or platinum rated PSUs do really have a higher efficiencies :)

If you run more than one of these cards, you might need to use PCI risers to get the cards further apart. Otherwise one card will 'breath' the hot air from the other one. The hashing speed on these is on the one end limited by the heat, but also (if cooled really well) by the on-card voltage regulators. They limit the clock rate to about 1GHz GPU and ~1575 GHz on the memory. For short times it seems you can exceed these (I reached up to 1100MHz on the GPU and ~1750 MHz on the memory without damage).

Cheers,
Haku