I have 270 and 270X, both Elpida. For 270X I have 445h/s for "-a 1" and 436h/s for "-a 4". Well, the difference is small, so may be in some cases "-a 4" can be better.
Don't forget to use "m" key to see exact immediate hashrate. Main hashrate that miner shows can be less because miner calculates it as TotalHashes/TotalTime, hashes are not growing when miner is connecting to pool or when it is disconnected, but TotalTime is always growing. Therefore main hashrate value becomes less if pool is not working properly. But when you press "m" key you see "raw" hashrate based on one GPU round only, it is useful to compare hashrates for different "-a" and "-h" values.

Send me first 20-30 lines of the log so I can see what card you use and "-a" and "-h" values.

Probably you are trying to start miner for Catalyst 14.7 on the system with Catalyst 13.x installed. Use appropriate miner version.
Also make sure that you updated all files, not only EXE file.

I released two builds of v9.0: for Catalyst 13.12 and for Catalyst 14.x.
Just download miner for Catalyst 13.12 if you use Catalyst 13.12, it is about 1% faster than miner for Catalyst 14.x.

Yes I will release v9.0 for Linux in a few days.

Very nice improvement.

My Results (Using the latest 14.9 AMD Drivers)
X3 270X went from around 1100 to 1280
X2 265X went from around 750 to 877
X3 290 went from around 1950 to 2150
X2 280X went from 1050 to 1150
1X 7750 went from 118 to 130
X2 290X went from 1550 to 1585

You need to release an Nvidia Miner. Keep up the good work.

Finally i tested and this is the best miner so far. I have 290 Tri-x and i am getting around 750/h per card with both drivers 14.7 and 13.12. Thanks for this Claymore.

Elpida is slag , 7950 and 280x are the same speed 450H.
expect Claymore optimization.

1. How many GPUs in rig?
2. How much RAM installed?

6 GPU on every rig and 4GB of RAM, virtual memory is set on 17000MB. I can set it 20k-30k