Bitcoin Forum

I got an offer on an XFX/ATI Radeon HD 7770 for $100 I figure I can get away with offering a bit lower, but I was wondering if this is a decent BTC miner? The guy said it would even be a good litecoin miner, but not sure what the main difference is? Still doing some research on the unit...

guy was right.

price is ok,

7770 is
 good for gaming
fair for ltc
bad for BTC
 
 for good gaming, good LTC , and great BTC ,  buy 5830/5850/5870

much , much better BTC power for dolar, a fair amount better in LTC , and even a little beter in gaming
it just will be older and only down thing is a little higher chance of failure due to aging.

I wouldn't buy it. That card uses about 80 watts of power and hashes at around 180Mh/s.  Lets assume that you pay 0.15 cents per kilowatt hour and it will take you over 10,000 days to break even.

Great assessment guys, was just looking at the Consolidated Litecoin Mining Guide and you guys are right on the money! Looking for deals on 5xxx units now... Any recommendations on mobos for multiple GPUs?

For mining, GPU's can run on x1 PCIe slots with the use of risers (http://cablesaurus.com/PCIe-x1-Extender-Cable). CPU/platform really doesn't matter, but LTC uses a fair bit of RAM. So focus more on PCIe slots, a little less on RAM, and the least on CPU (a single core will work fine). Then keep it cheap while getting a quality board. Gigabyte, ASUS, MSI, etc... All make good products

 I've been seeing  used 5850s/5870d  between 70-100, would be  a much  better option

How about this?

http://www.newegg.com/Product/Product.aspx?Item=N82E16813131837 (http://www.newegg.com/Product/Product.aspx?Item=N82E16813131837)

2 PCIe slots, so room for 2 or with 2 risers room for 4?
Does that sound right?

Probably a good board, but if you need to buy a sandy bridge CPU, it could turn into a pricey investment for mining.

Good call... What about power supply? Would it be wise to buy a power supply that could handle 2 or 3 ati 5970 since they seem to be the benchmark?

The more power the better! If you are going to get 3-4 58xx cards, you will want something in the ballpark of 850-1200w respectively. Make sure to have enough 6/8-pin PCIe connectors (usually 2x 6-pin per card for 58xx). If you plan to get 3-4 5970's, you will want powered risers, and 1250w+ PSU.

Are the connectors for powering the GPUs? Can you provide links for the connectors and risers? Im just trying to price a few things... Heres the mobo im currently looking at, i think this may be a good one, let me know your thoughts...

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=5727271&sku=B450-1155] (http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=5727271&sku=B450-1155)

PSU

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=606587&sku=V261-0100] (http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=606587&sku=V261-0100)

That still requires a sandy bridge CPU (as long as you're aware of that) 
Something like this (http://www.newegg.com/Product/Product.aspx?Item=N82E16813128521) would do with an AMD sempron CPU
The powered risers supply 12v power to the cards that would otherwise be supplied by the board when using x16 slots. On top of that, when using multiple high consumption GPU's (5970's) the board will have trouble supplying the required voltage. If you only use 2 5970's you probably won't need the powered risers.

The PCIe power connectors are dependent on the PSU you buy. In the specs, it should list the number of PCIe connectors the unit has.

1x risers: http://cablesaurus.com/PCIe-x1-Extender-Cable
powered risers: http://cablesaurus.com/PCIe-x4--%3E-x16-Adapter-Extender-Cable-w-Molex-Connector

Cablesaurus used to carry 1x risers with molex power but they aren't listed. Maybe you could contact them and see if they are still made.

The mobo is a good option, cheaper especially when you add the CPU mentioned. But it seems the powered risers wouldnt work because they are x4->x16, the mobo doesnt have x4... Unless x4 is no different than x1?

The powered risers I linked were just to illustrate what they are. The x4 is a longer slot so either you'll have to contact cablesaurus about 1x molex powered risers, file out the back end of the x1 slots to accept the 4x risers, or find a different mobo that is AM3 and has 4x slots.

This board has 3 PCIe x16 right out of the box, but is a little more expensive. http://www.newegg.com/Product/Product.aspx?Item=N82E16813157262

For Motherboards have a look here:-https://bitcointalk.org/index.php?topic=37880.0

For info on which Motherboards need pins shorted to run PCIe Extenders, look here:-https://bitcointalk.org/index.php?topic=36061.20

Be aware that Gigabyte M/Bs can be a PITA to boot from a USB Stick.

Dual GPU Cards seem to have a reduced life expectancy compared to Single GPU Cards --- heat issues

 5870 or 5850 Reference cards are my preference.

I was unaware of this! Any known/suspected reason for this?

Yea thats good info as I plan on running from a USB, thanks

i hope this will help you a little bit more: https://en.bitcoin.it/wiki/Mining_hardware_comparison

5970's are the most energy efficient GPU's for mining.  I can refer you to some people who'd sell these and/or some 5xxx series and 6xxx if you want.

P.S. BAMT (Big A Miner Thing) is a good usb sized OS for mining.

EDIT: Looked at the updated mining hardware comparison and 7750 give you 0.24 more Mhash/joule than the 5970 according to the site.

Uhh, 7970 > 5970 for power efficiency

7970 pushes 650mh/s @ 200w on average
5970 pushes 750mh/s @ 275w on average


not rocket science to determine energy efficiency here.

Energy efficiency is not much a priority as ive just had solar panels installed a few months ago. Im mostly concerned with keeping the rig going as long as possible (hopefully years), stable hash rates (not OCd), and keeping the system cool during the summer months down in SoCal. I would like to get about 3000khs, maybe even 3400khs without OCing if possible, so expecting to have at least 3 GPUs purchased and operating by spring. Should have 1 purchased at the same time as the desktop though, gotta learn how to run it.

But of course, I am going off of speculation that LTC will rise in value. But I have read things around this and other forums about not investing in LTC at all and dumping that $ into ASIC. But I've also heard the opposite as well. At any rate I would just like to start mining, just so that I have coins, and if I knew for sure ASIC would be released by the end of jan. Then I would hold my $, but that is not the case.

It is well documented, but if you dont know about it you can be running around in circles trying to figure out WTF is wrong. Seems to be something about DOS and FAT formats. There was a post by someone associated with the BAMT site about using two USB sticks as a work around. First stick loaded something, when that finished, the second stick loaded BAMT. The FAQ on BAMT shows compatible hardware and lists some Gigabyte boards as Not Compatible.
I never pursued it, I simply sold the two Gigabyte M/Bs that had caused me massive angst and bought two MSI M/Bs and that was the end of the problems with USB boot and getting PCIe slots recognised and working.
Only only the Gigabyte Company could tell you why they would set up something as Fxxcked Up as that.

That certainly is eff'ed up. I figured it had something to do with the BIOS, or boot device settings. I only run Gigabyte mobos, and now that you say it, I tried to run a linux bootable usb stick to secure erase my SSD, and had serious troubles, so I just put it on a bootable DVD and it ran with no problem.

5970's used to be the most efficient GPU, I hadn't looked at the new 7xxx series.  Thanks for the correction.

Edit: Looks like the 7750 is the most energy efficient GPU according to the website. NOT the 7970.