This entire post has to do with Phoenix 1.48 for what it is worth and with the poclbm and phatk kernels shipped with it.I found that -q 3 (or 2 or 4) produced extremely high stale rates and there were still network disconnections causing the GPU to idle. Howevever, with Phoenix, I did discover something that seems to be helping [probably with any pool]. People should experiment with setting this and see how their results change once the pool is stable.
-a (average samples) - Sets the number of samples to use for hashrate averaging. Default is 10. You might want to lower this for longer kernel execution times. (high aggression)
My original thought was that this would just affect the display of the hash rate in the miner. Indeed, that may be all it does. However, it occurred to me that perhaps some of the code is written in such a way that tracking the data and calculating this value may be just enough to effect performance [why offer the option otherwise ... almost seems silly]. So, I gave it a shot.
I will know in a bit if it helps with stale/rejected shares or not [or perhaps solve rates?].
Here is what I have:
Machine | Card | Phoenix Options |
Main Workstation - Win7 x64 Pro - Aero on | Radeon 6970 | VECTORS BFI_INT FASTLOOP=true WORKSIZE=128 AGGRESSION=9 -a 8 -k poclbm |
Dedicated Miner 1 - Win 7 x64 HomePrem - Aero off | Radeon 5850 | DEVICE=0 VECTORS BFI_INT WORKSIZE=128 FASTLOOP=false AGGRESSION=12 -a 8 -k phatk |
Dedicated Miner 2 - Vista 7 x64 Ultimate - Aero off | Radeon 5850 | DEVICE=0 VECTORS BFI_INT WORKSIZE=128 FASTLOOP=false AGGRESSION=12 -a 8 -k phatk |
Catalyst 11.5 drivers ONLY without Stream SDK installed [so, it is using 2.4 as supplied by the driver package].
Phoenix has been a stale nightmare for my 6970 and I have been using poclbm.exe to mine with [since the rates are the same as with phoenix and phatk doesn't help the 6970 yet]. My 5850s have averaged with poclbm.exe about 0.5% stale rates, however, with phoenix, the rate would over time go between 0.7% and 1.0% in several thousand shares. Switch to the phatk kernel in phoenix increased the MH/s rate by about 3.4% ... so now the stale rates are more than offset. Since I put -a 8 n there, not a single stale. Having said that, there have been very few long polling pushes since I started the test. My real question is what is the most appropriate value for this additional setting. I used 8 as a conservative start to see if there was an effect, but I am not sure how far it should be pushed. It may also be different with my 6970 since it is both different hardware, faster, lower aggression and using FASTLOOP. I will report back in a few hours.
So far, extremely good results against deepbit.net (the most similar to BTC Guild from a mining perspective I think), although again, the sample size is still very small and I have not many long polling requests yet. Not a single rejected/stale share in over 1000 shares submitted [between my miners]. I anticipate similar results with BTC Guild ... but right now I can't test these settings adequately here, but I will be back soon
. It may very well turn out that -a does absolutely nothing to affect stale shares [which I suspect is probably the case], but so far, it seems otherwise.
When the pool issues are resolved with BTC Guild such that I don't get any more idles or disconnects [need both to test this] and when I have taken a large enough sample on my current test, I will jump on back to BTC Guild and do an extended run, compare ... and stay ... tweaking as necessary.
So, I hope this may help some fellow miners out there and BTC Guild thread readers get the first heads up I guess
For what it is worth, it didn't seem to impact the results with -q 3 (tried -q 2 and -q 4 and -q 3 was the best of the poor options) meaning that things did not get worse than they were with -q 3, but it was impossible to really know what was really happening due to occasional network disconnects.