Performance anyone?!

[p2501]

Okay I was searching for some additional stats for poclbm. What I found was the following:

http://forum.bitcoin.org/index.php?topic=22965.0

I'm quoting here:



You can go to phatk's kernel.cl file (don't worry, it just sits there in the open, no need to recompile anything), find this line
#define Ma(x, y, z) amd_bytealign((y), (x | z), (z & x))
and change it to this line
#define Ma(x, y, z) amd_bytealign( (z^x), (y), (x) )
Once you've done it, restart the miner.

Using phoenix you find both kernels in the kernels folder (I know, kind of obvious, isn't it?! :p: ). This modification works for both kernels but only if you're using BFI_INT.

My results: Cayman cores gain ~14MHash consistently. 5xxx cores should gain even more. :up:

[Alpha]

hmm... i am going to have to try this... i could use an extra few hashes...

reporting back in a few...

update:

ok, went from ~308 mh/s on my 5830's at 1000/300 to ~ 315mh/s with just this change

[dairyFarmer]

Thanks, I just tried this out and got an extra 9 Mh/s on each of my 5830's.
Im running phatk in guiminer June 2011 release.

[Jen]

worked for me as well , better stable mhash

Jen

[OldChap]

+10 and 12 for me on 5870's Thanks p

[KaptainBlaZzed]

worked for me.

Nice find.:up:

[jcool]

If anything, this had a negative effect for me. Running 5870's on 2.1 SDK with poclbm, I went from 395-398 to 389-395 @ 900 core.

[OldChap]

I only have 5870's which on sdk 2.4, phoenix, phatk and this mod will run 400Mhash/sec @ core 900 now all I need is a working auto re-start for miners "connecting" longer than x seconds

[Musho]

I only have 5870's which on sdk 2.4, phoenix, phatk and this mod will run 400Mhash/sec @ core 900 now all I need is a working auto re-start for miners "connecting" longer than x seconds

Had problems with auto reconnecting with Phoenix 1.48 as well. 1.50 fixed this completely for me! Up and running for close to 2 days now, with a few disconnects in between. Didn't have to manually interfere a single time! Might be worth downloading the new release :) Don't forget applying this mod to the freshly downloaded 1.50 build

[cajer]

Mhashes went up from 315 to 330 on my 6950's, but stales are uncomfortably high at 2.2%.

[Musho]

Mhashes went up from 315 to 330 on my 6950's, but stales are uncomfortably high at 2.2%.

That's almost a 5% increase in MHashes/Sec, so it's actually performing better, even though you are getting a higher percentage stales. So don't worry too much about it :)

[Tom128]

I updated my 5 cards all of which had a good gain from this :up:

Now I just need to figure out why I have ONE card that keeps losing its connection and sits there for the entire day when I am at work connecting. It's a 5830, in a machine with a second 5830, using the exact same settings. The other one has NEVER went idle, this one does it daily. I went home for lunch today and restarted it, and just saw on BTCGuilds page that the same one has yet again stopped.

[don_xvi]

Maybe just try putting that one card onto another pool?

[OldChap]

If running wcg too try moving to just cancer or something like that or freeing up a core so your miner always has cpu available... and try phoenix 1.50 as mentioned above.

If you have an alternate gigabit card or port maybe look at that too.

[Tom128]

I was still running 1.48, switched to 1.5 hopefully that helps. I had 3 cards stalled when I got home today :( Not sure what they changed in the new phoenix but the file size went from 22k to over 6MB :eek: Looks like they also changed the output pattern, GPUMiner does not report the speed anymore, but it does report the accepted/stales at least. I ran it on the command line just to see and I got a slight Mhash increase as well, like 3 per card.