Are you using the latest miner? It's 1.3 avx-aes on the OP. I went from 142 kH/s to 380 kH/s on a stock i7-2600K when I upgraded to that.
Any link ? on the 1st page it's a 1.2c download.
It's on the first page, 1.3. Here's the link:
https://mega.co.nz/#!L1YgUIwB!_Xby8q1OkZCpatrJAkm9GJXrz2vLvYCiLgIsGFB4ph8
it says darkcoin-minerd-1.2c.zip on Mega.
I get it directly on github.
With my i7 4770K @4.4Ghz on minerd-corei7-avx :
[2014-03-11 09:20:19] Stratum detected new block
[2014-03-11 09:20:19] thread 4: 42967 hashes, 83.59 khash/s
[2014-03-11 09:20:19] thread 5: 42212 hashes, 82.12 khash/s
[2014-03-11 09:20:19] thread 3: 39700 hashes, 77.53 khash/s
[2014-03-11 09:20:19] thread 1: 42966 hashes, 83.75 khash/s
[2014-03-11 09:20:19] thread 7: 32619 hashes, 63.33 khash/s
[2014-03-11 09:20:19] thread 6: 41125 hashes, 80.16 khash/s
[2014-03-11 09:20:19] thread 2: 42288 hashes, 82.43 khash/s
[2014-03-11 09:20:19] thread 0: 42807 hashes, 83.28 khash/s
Total : 640kh/s
Very weak... I keep on GPU mining DRK !
By the way, if you want to join me, go on the P2POOL Node :
http://mightypool.net:7903