another 3% mining increase with poclbm kernel.cl

[dinker]

I'll wait for everyone to report back before I try out something from a guy named goxed 

[MiningBuddy]

Just tried this on my quad 5870 setup on ubuntu 11.04 using CC 11.5, SDK 2.1, using phoenix and poclbm + the 3% boost from http://forum.bitcoin.org/index.php?topic=22965.0
my hash rate went from 428.57 down to 426.26

[nelisky]

Well, marking it __local actually hints the opencl compiler on to where you want that variable to be stored. Local memory is the fastest iirc but there's a limited amount of it and if you are already on the limit you may end up getting the wrong thing in local memory, thus making everything slower.

This is obviously an oversimplification. For a little more " to the metal " kind of facts, my experimentation gives me:
- The 1~2% speed increase on a 5870, which can do -w 256 but is at the performance peak at -w 128.
- A fair amount of speed DECREASE on a 5970, with -w 256 which is where it performs best.
- The 1~2% speed increase on the same 5970, with -w 128, although even with the speed increase it's a little slower than the -w 256.

I'm using one of each 5970 and 5870 on a computer, but I don't want to use separate kernels, one for each card, so I'm stuck with the no __local version

[ThatOtherDude]

basically, add a  __local  key keyword to this line and it should increase your performance.

Sorry, this doesn't work for me, performance dropped 33% instead.

Are you using an ATI card? I know that I get a similar drop on my Nvidia, but I only have one and no ATI.  This may only work with ATI, all the reports are with ATI cards.

[bonker]

basically, add a  __local  key keyword to this line and it should increase your performance.

Sorry, this doesn't work for me, performance dropped 33% instead.

Are you using an ATI card? I know that I get a similar drop on my Nvidia, but I only have one and no ATI.  This may only work with ATI, all the reports are with ATI cards.

Only works with ATI card mate. Nvidia are a load of bollocks anyway with Bitcoin, total waste of time. 

[goxed]

I'll wait for everyone to report back before I try out something from a guy named goxed  

[Jack of Diamonds]

Didn't do anything to be honest. No performance dip but no increase either.

Tried on a 6990 and a 5850.

[BombaUcigasa]

basically, add a  __local  key keyword to this line and it should increase your performance.

Sorry, this doesn't work for me, performance dropped 33% instead.

Are you using an ATI card? I know that I get a similar drop on my Nvidia, but I only have one and no ATI.  This may only work with ATI, all the reports are with ATI cards.

'
Sure, but why?!

[bitless]

I've just tried this, didn't help me at all, but I've sent some BTCs your way anyways; thanks for trying to make it better!

[figvam]

Got about 2.5-3% less on a HD 4650.

[PcChip]

Went from 130 MH/s to 70 MH/s on my GTX570

[anty]

Decreases my hashrate on my 5850 from 370 (with the first 3%-fix) to 368.

[huayra.agera]

It seems the new poclbm already includes the 3%+ boost including the phatk kernel. No need to edit code.  . I have tested it and it matches my hashrate with the edited code.
Download here: http://forum.bitcoin.org/index.php?topic=1334.0

[zerokwel]

It seems the new poclbm already includes the 3%+ boost including the phatk kernel. No need to edit code.  . I have tested it and it matches my hashrate with the edited code.
Download here: http://forum.bitcoin.org/index.php?topic=1334.0

When I first looked at this I was thinking yea right... I was using GUI miner but decided I wanted something more command line when I set my second box up so I can just make a .bat file and stick it in startup.

Anyway up from 198mhash to 212 on a 5770. And up from 262 to 285 on a 6870

[Roland68]

Used the file posted here ...

no changes on my 5830 ...

looks like guiminer was already "optimized" for my card ...

nice mod anyway

[N4rk0]

AFAIK declaring those variable as local will make theme shared for all the the threads in the workgroup so it's possible to have a performance increase because you are using less memory , but speed doesn't matter when the calculations are all fucked up! !

[biohazord]

I made this change for my two 6950's (unlocked 908/310 and 850/310). The one clocked at 908 went up about 1 MH/s while the other went up 3-4 MH/s . I did the initial 3% increase mod and my rate shot up from 380 MH/S to 404 MH/s. To say the least I was more then pleased. After making this change it went from 404 to 405 (I sometimes see it jump to 405.. I'm not sure about my other cards numbers pre initial 3% increase but I remember it was on track with 3%.

I'm going to keep my eye on stales and make sure they don't creep up. I'm not too worried.

Every bit helps. Thanks!

[xanatos]

On my 5870 it jumped 16 mh from 385 to 401. I'm using the poclbm "old" kernel + the other +3% patch (that gives me only 1% of speedup :-( )

[ThatOtherDude]

basically, add a  __local  key keyword to this line and it should increase your performance.

Sorry, this doesn't work for me, performance dropped 33% instead.

Are you using an ATI card? I know that I get a similar drop on my Nvidia, but I only have one and no ATI.  This may only work with ATI, all the reports are with ATI cards.

Only works with ATI card mate. Nvidia are a load of bollocks anyway with Bitcoin, total waste of time. 

Ah, thanks for confirming my suspicions.  I've heard that ATI is the way to go when mining; however, Nvidia is a better choice for what I use my computer for mostly. 

[MiningBuddy]

On my 5870 it jumped 16 mh from 385 to 401. I'm using the poclbm "old" kernel + the other +3% patch (that gives me only 1% of speedup :-( )

Weird, what's the rest of your setup? I've listed mine above and this mod decreases my performance on every 5870 I have tried, mix of ubuntu/windows, ati versions & sdk.