but in reality i shouldn't have to overclock as it should be hashing at 1.2 TH/s minimum?
in reality, BTC H/w manufacturers tent to estimate the product's hashing speeds and power consumptions. Real world figures can differ dramatically.
My Sierra was stable on 604Mhz and hashing ~1.3THs, but once I took it apart. I could get it to about 1.4THs. Each board behaves differently. See
http://imgur.com/a/94wo7#28 for my last screen shot of cgminer and pics of my Sierra. You will notice different clock speed for each board in the Sierra.
Here's a snap shot of cgminer at the time of posting:
cgminer version 4.3.3 - Started: [2014-05-15 17:29:56]
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(5s):787.5G (1m):1.207T (5m):1.309T (15m):1.332T (avg):1.469Th/s
A:17328394 R:20517 HW:17106 WU:20522.3/m | ST: 5 SS: 0 NB: 97 LW: 20093194 GF: 0 RF: 0
Connected to us.ozco.in diff 461 with stratum as user quiveringgibbage.larry
Block: 4200d5e2... Diff:8.85G Started: [09:02:45] Best share: 58.2M
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[U]SB management [P]ool management [S]ettings [D]isplay options [Q]uit
0: HFB AL : 550MHz 75C 10% 0.79V | 102.6G / 429.1Gh/s WU: 5994.9/m A:5058818 R:5550 HW:14752
1: HFB KEN : 656MHz 85C 48% 0.78V | 299.2G / 484.7Gh/s WU: 6771.5/m A:5711371 R:6063 HW: 1529
2: HFB ROBERTA : 666MHz 85C 72% 0.78V | 453.3G / 555.2Gh/s WU: 7755.9/m A:6558205 R:8904 HW: 825
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[2014-05-16 09:02:58] Accepted 41b0b091 Diff 998/461 HFB 0 pool 0
While i was tuning the boards to find their max. stable hashing rate, cgminer occasionally gets ZOMBIEs and doesn't recover. But once I lay off the OCing, they can hash stable and if one should fail, cgminer tents to be able to recover it automatically after 60 secs of 0 share submitted.
Hash wild and Hash Fast,
QG