Decision Of Purchase - Used Vs New GPU ?

[ocl]

Enjoy everyone !

New generation AMD 4xx/5xx GPU's are currently out of stock at my local. Sellers are only willing to sell these new GPU's %20-%30 more than its price.
In deed there are some 280x,290x and HD7970's stand on market.

prices:

(New)RX470 $335
(New)RX480 4G $330
(New)RX480 8G $350

(Used)RX470 $250
(Used)RX480 $250-$300
(Used)R9 280X $125
(Used)R9 290X $160
(Used)HD7970 $140

What would be the most logical and budget friendly choice to dig Zcash ?

Bonus: I m also curious about 280X's TDP. I am a freshly new comer to the mining community and just want to test drive BIOS Modding, undervolting, efficiency and so on. If i can persuade myself that i was succeed, i may invest bigger.
I have a 5 Pci-e slot Gigabayte AM3+MOBO and i plan to make 5 GPU rig with it. But question is how much power needs to be supplied for these hunger 280X's. Can i supply 5x 280X with a Crosair RM1000i after undervolting ?

I will be much appreciated with your directions.

[1715009100]

1715009100

[1715009100]

1715009100

[1715009100]

1715009100

[1715009100]

1715009100

[1715009100]

1715009100

[ahmedjamal1998]

The problem is the proce that you typed in for the new cards is way too high.

Actually a new rx 470 should be about 250-280 but they are sold out everywhere so people are ising thus to put their own prices. Same goes for the 480s

I've been told that this shortage issue is going to be solved in two weeks.

[lautre]

wow insane prices

[Jdope]

These are insane prices, i wouldn't recommend buying new gpus with these prices at all, with these prices they have an ROI of atleast 4 months, that doesn't even count for electricity and mobo/psu set up, i would buy the used ones, they are expensive but at least nit that expensive.

[RobertD]

These old cards are only suitable for big server power supplies. Expect 150-250W from 280x, and 250-400W from 290x.
All my 290x rigs run triple power supplies (ATX + 1200W + 1200W).

4x 290x 1130/1250 129MH/s mining ETH 1250w from the wall using 2x 1200W server power supplies, dual mining 1700w

If you need cards now, buy some RX 560 4GB and return them in two weeks when RX 570 are available. Just make sure you can return them. I think Amazon has 30 day return policy.

[philipma1957]

plenty of nvidia 1080 ti's

make a zec/skein rig

2 of these

https://www.newegg.com/Product/Product.aspx?Item=N82E16814137104

this cpu
https://www.newegg.com/Product/Product.aspx?Item=N82E16819117625


mobo
https://www.newegg.com/Product/Product.aspx?Item=N82E16813128975&ignorebbr=1&cm_re=gigabyte_z270-_-13-128-975-_-Product

psu
https://www.newegg.com/Product/Product.aspx?Item=9SIA07236V1499&cm_re=quark_850-_-17-182-352-_-Product

ram

https://www.newegg.com/Product/Product.aspx?Item=N82E16820148856&cm_re=crucial_ddr4_4gb-_-20-148-856-_-Product

this is a riser free build   will do 650+650 = 1300 sols for zec  or 850+850 =1700 for skein

you can stay riser free and add a third card

https://www.newegg.com/Product/Product.aspx?Item=N82E16814500408&cm_re=zotac_1070_mini-_-14-500-408-_-Product

all 3 on the mobo and the 850 watt psu make for a small package pushing  1700 sols for zec  2150 for skein  and in a pinch  around 95 mh for eth

lower power use about 500 watts for zec and skein.