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Topic: 3% faster mining with phoenix+phatk, diablo, or poclbm for everyone - page 2. (Read 39054 times)

sr. member
Activity: 280
Merit: 250
Firstbits: 12pqwk
This patch successfully pushed the difficulty up by an extra 3% Cheesy
member
Activity: 112
Merit: 10
382 to 395, awesome.
sr. member
Activity: 378
Merit: 255
This tweek has been implemented into GUIminer.
So if you use GUIminer.
Just update.

Yes. As far as I know this has been implemented into the OpenCL kernel of all the main miners. If you want to implement this just update your miner. You can guarantee the change has been made by opening the kernel file and seeing if the Ma() line has been changed.
newbie
Activity: 37
Merit: 0
4850 no difference... pity... seems it's time to buy a new card...
newbie
Activity: 42
Merit: 0
280 to 289 on a stock speed 5850... will be using this on all my miners, thanks!

exact same here
legendary
Activity: 1428
Merit: 1001
Okey Dokey Lokey
This tweek has been implemented into GUIminer.
So if you use GUIminer.
Just update.
member
Activity: 112
Merit: 10
Firstbits: 1yetiax
410 -> 420 (2.4%) on my HD5870 with the new DiabloMiner! Suh-weeet! Thanks a bunch!
legendary
Activity: 1162
Merit: 1000
DiabloMiner author
On normal Radeons at stock clocks and voltages, and are not overheating, have a known error rate (which is something like 1 error per several hundred million instructions)

One error per several hundred million instructions... where are you getting that information from? (an honest question, I'd like to learn more)

A 58xx series, from information I can find, can do between one and four instructions per clock.  If it is clocked at 775000000 cycles per second (775 MHz), that's up to 3.1 billion instructions per second.  So according to your information there would be many errors per second.

I think I meant 1 per several hundred billion. Its in the chip specification somewhere, ask AMD.

Quote
a silicon chip is not supposed to have errors, and will only occur if: incorrect voltage, incorrect temperature range, the silicon chip itself is faulty, something extremely rare such as a cosmic ray bouncing off and [in the case of RAM] 'flipping a bit' perhaps once every few weeks

Bzzt, wrong. GPU hardware does not use the same manufacturing process CPU hardware typically does. GPUs are not mission critical hardware, and rare calculation errors are considered acceptable.

You are correct about "incorrect" voltage, however you assume that it is incorrect at all. The professional versions of these cards run at lower clock rates and lower voltages to reduce the error rate. Consumer cards are not ran at incorrect settings, they are merely ran at settings that lead to acceptable levels of errors.

This is shown up quite well if you run something like Folding or Seti on your GPU, you will notice a lot more invalid work showing up than you do using the CPU variant and has far as I am aware work for these two does not expire within any reasonable length of time unlike bitcoin so these are actually invalid results and not just "stale".

No, its invalid on mining as well. My miner has a HW error counter, it only ticks up when the HW produces a hash it thinks produces H == 0, but when double checked it doesn't.
legendary
Activity: 1246
Merit: 1011
359 -> 367 (2.2%) on my two 5850's (900/300 1.01V).

Thank you kindly.
member
Activity: 76
Merit: 10
On normal Radeons at stock clocks and voltages, and are not overheating, have a known error rate (which is something like 1 error per several hundred million instructions)

One error per several hundred million instructions... where are you getting that information from? (an honest question, I'd like to learn more)

A 58xx series, from information I can find, can do between one and four instructions per clock.  If it is clocked at 775000000 cycles per second (775 MHz), that's up to 3.1 billion instructions per second.  So according to your information there would be many errors per second.

I think I meant 1 per several hundred billion. Its in the chip specification somewhere, ask AMD.

Quote
a silicon chip is not supposed to have errors, and will only occur if: incorrect voltage, incorrect temperature range, the silicon chip itself is faulty, something extremely rare such as a cosmic ray bouncing off and [in the case of RAM] 'flipping a bit' perhaps once every few weeks

Bzzt, wrong. GPU hardware does not use the same manufacturing process CPU hardware typically does. GPUs are not mission critical hardware, and rare calculation errors are considered acceptable.

You are correct about "incorrect" voltage, however you assume that it is incorrect at all. The professional versions of these cards run at lower clock rates and lower voltages to reduce the error rate. Consumer cards are not ran at incorrect settings, they are merely ran at settings that lead to acceptable levels of errors.

This is shown up quite well if you run something like Folding or Seti on your GPU, you will notice a lot more invalid work showing up than you do using the CPU variant and has far as I am aware work for these two does not expire within any reasonable length of time unlike bitcoin so these are actually invalid results and not just "stale".
legendary
Activity: 1162
Merit: 1000
DiabloMiner author
On normal Radeons at stock clocks and voltages, and are not overheating, have a known error rate (which is something like 1 error per several hundred million instructions)

One error per several hundred million instructions... where are you getting that information from? (an honest question, I'd like to learn more)

A 58xx series, from information I can find, can do between one and four instructions per clock.  If it is clocked at 775000000 cycles per second (775 MHz), that's up to 3.1 billion instructions per second.  So according to your information there would be many errors per second.

I think I meant 1 per several hundred billion. Its in the chip specification somewhere, ask AMD.

Quote
a silicon chip is not supposed to have errors, and will only occur if: incorrect voltage, incorrect temperature range, the silicon chip itself is faulty, something extremely rare such as a cosmic ray bouncing off and [in the case of RAM] 'flipping a bit' perhaps once every few weeks

Bzzt, wrong. GPU hardware does not use the same manufacturing process CPU hardware typically does. GPUs are not mission critical hardware, and rare calculation errors are considered acceptable.

You are correct about "incorrect" voltage, however you assume that it is incorrect at all. The professional versions of these cards run at lower clock rates and lower voltages to reduce the error rate. Consumer cards are not ran at incorrect settings, they are merely ran at settings that lead to acceptable levels of errors.
newbie
Activity: 39
Merit: 0
i dont know what this did but i switched from open CL to phoenix changed a bunch of flags and went from 275Mh to 290MH on each of my 4 6870 cards

thanks!
sr. member
Activity: 418
Merit: 250
On normal Radeons at stock clocks and voltages, and are not overheating, have a known error rate (which is something like 1 error per several hundred million instructions)

One error per several hundred million instructions... where are you getting that information from? (an honest question, I'd like to learn more)

A 58xx series, from information I can find, can do between one and four instructions per clock.  If it is clocked at 775000000 cycles per second (775 MHz), that's up to 3.1 billion instructions per second.  So according to your information there would be many errors per second.

When you talk about hardware errors, are you sure you're not talking about rounding errors?

a silicon chip is not supposed to have errors, and will only occur if: incorrect voltage, incorrect temperature range, the silicon chip itself is faulty, something extremely rare such as a cosmic ray bouncing off and [in the case of RAM] 'flipping a bit' perhaps once every few weeks

Hardware errors cause things like bluescreens, frozen machines, display driver crashes and the like.  You would have to get REALLY lucky for a hardware error JUST SO HAPPEN to only effect something that isn't important, like what color this or that pixel is, or something mundane like that.  Most likely if there's a hardware error the odds are it won't happen on a piece of data where it doesn't matter, it will probably crash the system.

What I can find on cosmic ray bit flips:
http://www.zdnet.com/blog/storage/dram-error-rates-nightmare-on-dimm-street/638
http://lambda-diode.com/opinion/ecc-memory
http://www.cs.toronto.edu/~bianca/papers/sigmetrics09.pdf
legendary
Activity: 1162
Merit: 1000
DiabloMiner author
Diablo showed very very few hardware errors (according to the forums, it was low .. less than 3 in 1000 for any card, and in some one case only 1 in ~2000)

Hardware errors?  Any hardware error means you've pushed the boundaries of either: voltage, clock speed, or heat...  Reduce one

No it doesn't.  Go read carefully.  Hardware checks are turned off intentionally by Diablo (and I believe all GPU mining software)

I'll cut you off there. You cannot shut off error correction via OpenCL, not that there is any to actually shut off.

The only thing I shut off is HW error message spamming when BFI_INT is on (because BFI_INT is a large hack and certain usages confuse the driver). HW error checking is still enabled in the miner, and the counter still ticks up.

legendary
Activity: 1162
Merit: 1000
DiabloMiner author
No it doesn't.  Go read carefully. there are always going to be occasional hardware errors for this kind of thing

All this writing and all I really said is that hardware errors are normal and does occur with ALL GPUs.

I'm sorry Veldy but you're incorrect

GDDR5 does have error correction however, which is why you can push it past its boundaries and not crash, but will get reduced performance from all the error-corrections.  

Aside from GDDR5 and specific ECC ram, any hardware error would cause huge problems up to and including system lockup. Later operating systems (Win7 in my case) have gotten better at coping though, if you're lucky you get a "Display Driver has Stopped Working" error and not a hard-freeze.

Edit: I'll just edit this post in response to the one below to avoid spamming this thread with offtopic posts to say that we'll just agree to disagree

Consumer GPUs do not use ECC-enabled GDDR5.

The HW errors, however, are caused by naturally unstable hardware. On normal Radeons at stock clocks and voltages, and are not overheating, have a known error rate (which is something like 1 error per several hundred million instructions), and do not have excessive (or really, any) internal checks.

This is not a defect in the hardware. GPUs are for playing video games. Scientific apps that are searching for a needle in a haystack (such as what we do) double check the result.
newbie
Activity: 28
Merit: 0
Wow this really worked!!

2 6950's both:

380 -> 395 Mhash/s

Thank you so much!!
member
Activity: 76
Merit: 10
My 5870 (950/315) went from 418 -> 428 Mhash an increase of 10 Mhash or about 2.5%.
newbie
Activity: 32
Merit: 0
anyone notice 'slower' performance? I am noticing 'slower' performance with SDK 2.1
newbie
Activity: 39
Merit: 0
Oh, thanks for such a trick!
5770: 210 -> 214
5850: 364 -> 372
member
Activity: 98
Merit: 10
No it doesn't.  Go read carefully. there are always going to be occasional hardware errors for this kind of thing

All this writing and all I really said is that hardware errors are normal and does occur with ALL GPUs.

I'm sorry Veldy but you're incorrect

GDDR5 does have error correction however, which is why you can push it past its boundaries and not crash, but will get reduced performance from all the error-corrections.  

Aside from GDDR5 and specific ECC ram, any hardware error would cause huge problems up to and including system lockup.

No, I am not wrong and I wasn't referring to GDDR5 or any specific memory.  As you know, memory itself must have error correction or a system simply could not run.  Anything that does I/O will have errors.  There are several types and there are several cases where it is better to let them slide than to fix them [and odd pixel or triangle or hexegon somewhere may be better than the performance cost of using error correction to recover it].   Also, as I have mentioned, hardware error correction/check is turned off by Diablo; with that in mind, one must expect errors [or there would be no need to have the error correction in the first place].

For the sake of this thread and forum, I will leave it at that.  You can respond if you like, say what you need to say.  Interested readers should do their research [including myself].  One thing that I am sure of though is that Diablo3 is no dummy and if errors are expected according to what he wrote about the Diablo miner [see the thread], then I believe he is working off of reliable and true information.
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