Yes the idea is good. But you get them cheaper on Ebay. Plain regular risers or USB3.0 ones that are very nice in terms of use of space.

If you buy the ASRock H81 BTC mobo you don't need powered risers as the mobo has 2 4 pin molex connectors you can connect the PSU to so the extra 75W comes from them.



For the Linux users; is it possible to run more than 5 cards there? Win8 has a max of 5 and only for the HD79** series there is a custom driver available to run 6.

Listen to this. I have 3 280X.

 1 Gigabyte 280X windforce OC
 2 Sapphire 280X regular model.

The -t 0,0,1,1,2,2 -a 1 scrypt did not work well enough for my setup. I reached 8400 CPM with it.
I think I found out why.

 The sapphires run now each in their own window @ 3496 & 3457 CPM each using 2 threads and -a 1 algorith

 The Gigabyte does not like that. It stays around the 1.400 cpm mark. I do use it for the monitor but ok.
 So i delete the -a 1 scrypt; 1600 cpm. MEH
 So I take it back to basics: 1 thread and no algorith choice.
 Now it runs happily at 2.600 cpm.

 ODD

So one 280X is not the other 280X and for PTS mining I would RIGHT NOW recommend the Sapphire regular version of the 280X. BUT just because of my own experience. I like the Gigabytes but I can't find the optimal configuration yet.

 I am happily chugging away at 9700 cpm in total now with these 3 cards
 And @ 1150 shares per hour.

 Not too shabby. With the right cards a full rig of 280Xs (5 pieces) would ramp up to 16.500 cpm and 1.800+ spm.

Tested under power, increased from 780 watts to 880 watts, increase the percentage of 12.8%
Speeds from 11200 CPM raised to 14020 CPM, increase the percentage of 25%

4 * 280x win7 64bit

I am a bit confused over the correct scrypt to use.

Can you please show yours?

I am using 3 280X cards running @ 1150/1500 and I get 7880 cpm in a single screen. When I open a second thread I get 2330 cpm on that thread and the first thread slowly goes lower and lower untill it goes under the 7880 total cpm together. Should I use the -t 0,0,1,1,2,2 command? And also add -a 1 or not at all?