Well I'll get 7 280x at 117$ per pieces.. 4 are gigabyte version and the rest Asus.... They where used for mining and some of them still have warranty.. It's that a good deal?
You will have a problem finding a large enough power supply for 7 280X cards. While it is possible to use dual power supplies, they may not provide a stable environment. If you are in the USA, plugging the rig into the socket(s) for a single room will load the circuit to near capacity. 280X cards do a good job hashing, perhaps ~310 Sol/s.
R9 Fury cards are more expensive, but more power efficient and hash at ~460 Sols/s. A single 1600W power supply can power 4 R9 Furies and 1 or 2 smaller R9 series cards.
Larger rigs are often less stable. If this is your first build, start with 4 cards and expand. Larger rigs are impressive, but start simple first. Two stable four-card rigs with smaller power supplies will produce more hash at less expense, and allow you to turn on a light or make toast. Place the rigs in separate rooms. If you are in a college dorm, that will save the embarrassment of constant circuit overloads. --scryptr
Thank you for your detailed answer.. I'm from Europe so there won't be a problem with the power line .. This is my second build... Well I can't find any used Fury gpus. I'm planning on using 2 psu each with 1000w with a h97 anniversary with 7 pci Slots and USB risers. As for the CPU I'll use a dual core processor, and 8 GB of ram.
I was thinking of making 2 rigs but that will impose buying a new motherboard, ram and CPU and that adds up.
GOOD LUCK! --
I got long-winded and added to my original post. H97 Anniversary is a good choice. 2 micro-ATX boards might cost less, though. My first rig was six 280X and two 1000W PSUs. It crashed constantly running early versions of SGminer. I thought one card was bad and replaced it I now have eight matching 280X cards, all purchased new, and all running fine on 2 four-PCI slot micro-ATX boards, each with a 1200W PSU. They are in different rooms, of course. --scryptr
