Here is my 4GH [scrypt] Rig, with 6x HIS 7950 IcqQ x2 @666 khash/s - update: 673 
This was fun to build while waiting way too long for my grakas
http://i42.tinypic.com/ojhu1u.jpg
old:
http://i41.tinypic.com/ixs8lx.jpg
new:
http://i41.tinypic.com/5vd5w.png
(actual hashrate value in cgwather and shares accepted count in cgminer are buggy)
The current setup is:
MSI Z77A-G45
6x HIS 7950 IceQ X2
LEPA 1600W NT
4GB G-Skill Ripjaws
40 GB Seagate HDD
current Riser: 3*powered x1, 1*non powered x1, 1*x16 riser@2nd Slot(always counted from Top)
Rig consumes 1490W now.
-skipped using 4th Slot.
-used shortening mod on 5th Slot.
-flashed Bios with 1003,1490@1.087 VDDC
-used optimized kernel binary from https://forum.litecoin.net/index.php/topic,6058.75.html
-used 13.1 Driver from techpowerup, installed it without sdk and manually installed amd app sdk(dont know which version is installed right now)-
-currently running under Windows8 64 bit with cgwatcher and cgminer3.5 with param:
CoreClock: 1092 Mhz
MemClock: 1490 Mhz
Powertune: 14
VDDC: 1.087V
ThreadConcurrency=22400 Intensity=19 GpuThreads=1 Vectors=1 Worksize=256
My old config was 21712TC with 1003(Core)x1490(Mem)@1.087V - By increasing core hashrate fall down - I stucked at 599kh/s.
Each card consumed 208W
With the new kernel binary and TC switch to 22.4k, it increased to 616Kh/s (2.75%)
..and it had also brilliant secondary effect:
Now i`m able to increase core frequency almost linear to my hashrate. I stopped with 1092Mhz with 666Mhz and...
FINALLY GOT MY 4 GH/s !!!!
Each card now consumes 224W so I think i have to do some more undervolting again
--
Edit:
Did a lot fine tuning and ended with:
+ pushed core to 1104 on 5 cards => + 7 Kh/s each
+ decreased vddc to 1.081V => - 2.5 W each
+ switched TC to 24k => + 2 KH/s each
just love the result
plus ~47 Kh/s, for 12.5W less power !
pictures get updated, when it pass the long term stability test
--
Quirks:
With my second rig I had some stability issues. The reason for that had been those fucking default energy-saving options of windows.
- Switch to your energy profile menu and select advanced settings. Disable energy saving for PCI Express
Scrypt mining just sends a few instructions & results over PCI Express, so this could be missinterpreted as a low bus usage.
when you want to rebuild this, you first have toundervolt the graphicards bios before mining, cause you would exceed the PSU limits!
--
gpu mining is just a wonderful hobby
hope u enjoy it and could probably find anything to incease your hashrate too
This was fun to build while waiting way too long for my grakas
http://i42.tinypic.com/ojhu1u.jpg
old:
http://i41.tinypic.com/ixs8lx.jpg
new:
http://i41.tinypic.com/5vd5w.png
(actual hashrate value in cgwather and shares accepted count in cgminer are buggy)
The current setup is:
MSI Z77A-G45
6x HIS 7950 IceQ X2
LEPA 1600W NT
4GB G-Skill Ripjaws
40 GB Seagate HDD
current Riser: 3*powered x1, 1*non powered x1, 1*x16 riser@2nd Slot(always counted from Top)
Rig consumes 1490W now.
-skipped using 4th Slot.
-used shortening mod on 5th Slot.
-flashed Bios with 1003,1490@1.087 VDDC
-used optimized kernel binary from https://forum.litecoin.net/index.php/topic,6058.75.html
-used 13.1 Driver from techpowerup, installed it without sdk and manually installed amd app sdk(dont know which version is installed right now)-
-currently running under Windows8 64 bit with cgwatcher and cgminer3.5 with param:
CoreClock: 1092 Mhz
MemClock: 1490 Mhz
Powertune: 14
VDDC: 1.087V
ThreadConcurrency=22400 Intensity=19 GpuThreads=1 Vectors=1 Worksize=256
My old config was 21712TC with 1003(Core)x1490(Mem)@1.087V - By increasing core hashrate fall down - I stucked at 599kh/s.
Each card consumed 208W
With the new kernel binary and TC switch to 22.4k, it increased to 616Kh/s (2.75%)
..and it had also brilliant secondary effect:
Now i`m able to increase core frequency almost linear to my hashrate. I stopped with 1092Mhz with 666Mhz and...
FINALLY GOT MY 4 GH/s !!!!
Each card now consumes 224W so I think i have to do some more undervolting again
--
Edit:
Did a lot fine tuning and ended with:
+ pushed core to 1104 on 5 cards => + 7 Kh/s each
+ decreased vddc to 1.081V => - 2.5 W each
+ switched TC to 24k => + 2 KH/s each
just love the result
plus ~47 Kh/s, for 12.5W less power !pictures get updated, when it pass the long term stability test
--
Quirks:
With my second rig I had some stability issues. The reason for that had been those fucking default energy-saving options of windows.
- Switch to your energy profile menu and select advanced settings. Disable energy saving for PCI Express
Scrypt mining just sends a few instructions & results over PCI Express, so this could be missinterpreted as a low bus usage.
when you want to rebuild this, you first have toundervolt the graphicards bios before mining, cause you would exceed the PSU limits!
--
gpu mining is just a wonderful hobby
hope u enjoy it and could probably find anything to incease your hashrate too