All tests ran with the same frequency etc..
Each algo can be optimized, but for comparison, it's good.
Power at the wall:
80-90w
scrypt
550W - 2 x 720khs
Scrypt-N
537W - 2 x 350khs
Scrypt-jane
485W- 2 x 133khs
Groestl
271W - 2 x 7 025khs
Myr-G
295W - 2 x 9 920khs
skein
440 W - 2 x 212 500khs
Keccak
430W - 2 x 316 000khs
X11
285W - 2 x 2 080khs
Result : Groestl is the most gpu friendly algo, for power, temp and noise, even better than X11
a little tuning on one of mine:
4 R9 280x + 1 x 7950.
3 R9 are overclocked at 1250MHz, the 4th at 1150MHz - 1.2v
The 7950 runs at 1100MHz - 1.15v
Memory for all 4 run at 1000MHz
Look at the temp (scrypt : between 75 to 83°C)
--------------------------------------------------------------------------------
(5s):38.01M (avg):37.30Mh/s | A:2108 R:0 HW:0 WU:136.074/m
ST: 1 SS: 40 NB: 18 LW: 1538 GF: 0 RF: 0
Connected to Pool 0 (stratum) diff 0.000 as user azhago.2
Block: 244150fe... Diff:101 Started: [20:44:59] Best share: 4.35K
--------------------------------------------------------------------------------
[P]ool management [G]PU management [Settings [D]isplay options [Q]uit
GPU 0: 45.0C 3366RPM | 8.036M/8.035Mh/s | R: 0.0% HW:0 WU:29.886/m I:24
GPU 1: 45.0C 3258RPM | 8.036M/8.035Mh/s | R: 0.0% HW:0 WU:28.166/m I:24
GPU 2: 48.0C 3337RPM | 8.036M/8.035Mh/s | R: 0.0% HW:0 WU:33.747/m I:24
GPU 3: 48.0C 3233RPM | 7.392M/7.378Mh/s | R: 0.0% HW:0 WU:20.878/m I:19
GPU 4: 38.0C 5277RPM | 5.845M/5.835Mh/s | R: 0.0% HW:0 WU:23.396/m I:20
--------------------------------------------------------------------------------
[20:45:30] Accepted 0958aa9c Diff 27/0.000 GPU 4 at Pool 0
[20:45:38] Accepted 0eb6b909 Diff 17/0.000 GPU 2 at Pool 0
[20:45:39] Accepted 1dbce2e6 Diff 0.000/0.000 GPU 0 at Pool 0
[20:45:41] Accepted 181052de Diff 10/0.000 GPU 2 at Pool 0
[20:45:45] Accepted 05700585 Diff 47/0.000 GPU 0 at Pool 0
[20:45:49] Accepted 131f1947 Diff 13/0.000 GPU 1 at Pool 0
[20:45:50] Accepted 06b61d40 Diff 38/0.000 GPU 4 at Pool 0
[20:45:54] Accepted 307ecd9e Diff 1.35K/0.000 GPU 4 at Pool 0
[20:46:02] Accepted 10c2d09e Diff 15/0.000 GPU 0 at Pool 0
[20:46:04] Accepted 126ecee9 Diff 13/0.000 GPU 0 at Pool 0
I can only get 6.4 Mh/s from my R9 280's what are your settings?