Catalyst 11.7 mining speed fluctuation

[Mr.Prayer]

Earlier i used 11.6 catalyst drivers. I got stable 440 MH/s mining speed from my OC'd 5870 with any combination of miners.

Today, after updating to 11.7 i noticed something strange.
While mining with single miner with AGGRESSION=12 i still get 440 MH/s, but if i'll add to that one more miner with AGGRESSION=6 the speed is starting to jump from 440 up to 550 MH/s.

Is that normal?
Did anybody else noticed that?
Is it really the speed changing or just inaccurate calculation?

PS: I'm using GUIMiner, with poenix miner and custom phatk kernel.

[RvdE]

I'm currently using cgminer by ckolivas (http://forum.bitcoin.org/index.php?topic=28402.0) and some users have reported issues with GPU mining after upgrading to 11.7.

It could lead to high CPU usage and other issues. Downgrading seems to be the only solution for now.

[Mr.Prayer]

Actually i continued mining with two miners config and i got higher speeds confirmed by pool i'm using.
Strange, but it looks like it really works better that way.

I'll continue monitoring and report back later.

[RvdE]

Actually i continued mining with two miners config and i got higher speeds confirmed by pool i'm using.
Strange, but it looks like it really works better that way.

I'll continue monitoring and report back later.

I'm interested to know your findings since I'm delaying the upgrade to 11.7 until more information on the (supposed) bug has been collected.

Glad it works for you though.

Just out of curiosity... is your CPU usage high now that you've upgraded ?

[dishwara]

I used 11.7 July 4 preview, where i didn't find any difference in hashing.
I have 2 5870 cards mining @ 434 & 427 Mhash/s.

Then i tired the 11.8 preview, that too i see no difference.
So, even though i didn't use stable 11.7, i can say in beta 11.7 i saw no difference & jumping as mentioned in 1st post.

[Mr.Prayer]

Just out of curiosity... is your CPU usage high now that you've upgraded ?

I'm using Phoenix 1.5, so i got 100% on single core even when i used 11.6.
No difference after updating to 11.7.

So, even though i didn't use stable 11.7, i can say in beta 11.7 i saw no difference & jumping as mentioned in 1st post.

Try to add second miner for each card. I got no difference while using single miner.

[dishwara]

2 miners for one card?

[Mr.Prayer]

Yes.
I did it for partial backup, since GUIMiner doesn't support normal backup for Phoenix miner.
So, primary miner get around 90 MH/s less speed, but second one can mine at ~400 MH/s if first one fails.
With 11.6 i got the same 440 with single/double miner config.
With 11.7 i'm getting 440 with single and 430-480 (sometimes it jumps to 530+) with two miners on single card.