Where did my 5 Mhashes/sec go?

[Axez D. Nyde]

Hi!

I replaced three of the components in my PC in order to increase the efficiency of my mining. An ASRock Mobo made room for a Gigabyte P41T-D3 and 1GB DDR2 got replaced by 2GB DDR3. Also the Pentium D 3.0 GHz is now no more, in its spot a Celeron now keep the machinery going.

As expected, the power consumption went down from 355W to 270W. But also the hashrate lost 5 MHashes/sec from 421 to 416. Any ideas what causes this? All other sttings stayed the same. I noticed that CPU-Z now claims GPU usage is down to 97% from 99%.

[Zwenny]

Which Miner? Try Phoenix with pathk2 and post results.

[Axez D. Nyde]

using phoenix 1.50 and phatk 2.2
results see first post.

[BkkCoins]

How does CPU usage look on the new machine? High CPU usage will often detract from GPU utilization. And if by chance you changed driver version that can have an effect.

[Axez D. Nyde]

Oh yes, CPU usage seems to be 100% all the time now.

I did not change, update or remove any drivers.

[bcforum]

Oh yes, CPU usage seems to be 100% all the time now.

I did not change, update or remove any drivers.

Perhaps the Celeron isn't fast enough to carry the load. The CPU has to build the work, deliver it to the GPU, and verify the results when it is done. If your CPU is to slow, you'll lose hash speed.

[Fletch]

Perhaps the Celeron isn't fast enough to carry the load. The CPU has to build the work, deliver it to the GPU, and verify the results when it is done. If your CPU is to slow, you'll lose hash speed.

Not likely. I'm running 3 5850's and the CPU load is about 1%.

Edit: That's on the slowest AMD CPU I could buy. I know there's a bug in the Windows ATI drivers that causes the CPU to be pegged at 100%.

[BkkCoins]

Perhaps the driver that worked fine on the first MB has issues with the new one. Check your driver version and if it's 11.7 or 11.8 (newest) then I'd try a downgrade to 11.6 as that was the latest version that didn't have a CPU utilization bug. But from what I hear on Windows it requires dummy plugs. (I'm using Ubuntu so don't need them anyway).

CPU use should be in the low single digit percent range generally so the fact it's up high indicates something not happy. Loads of miners here are using the lowly Sempron even on 4 card configs so I'd doubt the Celeron isn't able to handle it.

[Axez D. Nyde]

Mmh. That the CPU load is now always 100% bothers me a little. That must surely cost some extra energy. I don't use dummyplugs as I only use one VGA and the monitor is plugged in it. Checking my Catalyst rigth away but I believe I have 11.6 installed. Celeron should be fast enough for any number of cards.

[Fletch]

Mmh. That the CPU load is now always 100% bothers me a little. That must surely cost some extra energy. I don't use dummyplugs as I only use one VGA and the monitor is plugged in it. Checking my Catalyst rigth away but I believe I have 11.6 installed. Celeron should be fast enough for any number of cards.

Yes. 100% will indeed consume quite a bit more energy. Also, 100% CPU is a driver bug, nothing else. Try 11.7 and 11.8 and see if that helps. Also try different stream sdk versions.

[Axez D. Nyde]

Well, I checked and I had been running 11.7. Tried 11.8 withouth any changes and then reverted to 11.6.
Now the CPU's running at 65%, still a little high? And there seems to be no noticable change in power consumption. My wattage meter is to crappy to pick up small changes.