is it safe to set core frequency to 300Mhz (Extreme) for avalon?

[cypherdoc]

I have a new firmware we ( ckolivas,xiangfu ) just built.

newest cgminer 2.10.5a, much more stable. no more restarts.

PM for a download link if you wish to try.

Reply was 'STATUS=S,When=1365179845,Code=11,Msg=Summary,Description=cgminer 2.10.5a|SUMMARY,Elapsed=64024,MHS av=74133.46

thank you for this.

is the cgminer 2.10.5a solely for Avalon use?

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[Bogart]

I have been running mine at 300MHz for a while now.  I have not noticed any ill effects.  The fans seem to run a little faster.

I believe ngzhang said that running at 300MHz will increase power consumption, and will raise the HW error percent slightly.

[BitSyncom]

I have been running mine at 300MHz for a while now.  I have not noticed any ill effects.  The fans seem to run a little faster.

I believe ngzhang said that running at 300MHz will increase power consumption, and will raise the HW error percent slightly.

it's proportional, fan is dynamic according to temp.

[SebastianJu]

I did some overclocking with GPUs and as far as i read the fear of people that simple overclocking can dramatically reduce the lifetime of a chip isnt correct. The biggest problem for chips is when you set the voltage higher. The electron migration (or something called similar) will make the chip go down faster this way. Thats a fast way to crash a chip.
The second way, but far less dangerous is high temperature. At least GPUs shut down when they are too hot. Asics dont do this so one should be cautious with the temperature. But a higher temperature is shortening the life of a chip but not very much.
The third is to overclock the frequency. It doesnt hurt in its own. The only danger is the high temperature. So if one manages to keep the temperature at the same level while overclocking it shouldnt hurt the chip in way that its noticeable.
If you want to make your chip live long and have better power then overclock and undervolt it. That will give higher speed, lower temperature and the overall live of the chip will be extended.

Im not a pro so if im wrong let me know.

[allinvain]

300Mhz = safe, but result may vary.

I tried this this morning.  Hash went from 68,000 -> 71,000.  It ran for about 2 hours and then stopped.  I had to call my wife an teach her how to restart the computer over the phone.  We set it back to 282 MHz and it has been running for 5 hours.  In 4 days it has never stopped when set to 282 Mhz.  I think I will leave it there.

I have a feeling the reason it stopped was because the power supply could not handle it.

[allinvain]

I did some overclocking with GPUs and as far as i read the fear of people that simple overclocking can dramatically reduce the lifetime of a chip isnt correct. The biggest problem for chips is when you set the voltage higher. The electron migration (or something called similar) will make the chip go down faster this way. Thats a fast way to crash a chip.
The second way, but far less dangerous is high temperature. At least GPUs shut down when they are too hot. Asics dont do this so one should be cautious with the temperature. But a higher temperature is shortening the life of a chip but not very much.
The third is to overclock the frequency. It doesnt hurt in its own. The only danger is the high temperature. So if one manages to keep the temperature at the same level while overclocking it shouldnt hurt the chip in way that its noticeable.
If you want to make your chip live long and have better power then overclock and undervolt it. That will give higher speed, lower temperature and the overall live of the chip will be extended.

Im not a pro so if im wrong let me know.

Maybe someone can correct me if I'm wrong but I do believe the Avalon ASICS will shutdown if they get too hot. Now I doubt that each chip has a thermal sensor in it but at the very least they might have a thermal sensor somewhere on the ASIC PCBs or somewhere around. It would be pretty silly if they went through all the trouble of designing bitcoin mining ASICS and built no thermal protection in the system whatsoever. After all these are money printing machines, no?

[Tyger]

Well the fans adjust there speed so i guess there are sensors on there yeah.

[allinvain]

Well the fans adjust there speed so i guess there are sensors on there yeah.

True, but the sensors could be just ambient air temp sensors - meaning they just sense the temp in a given area, and not exactly on or near the ASIC die itself.

[thebaron]

I'm surprised they're running the power supplies so close to the rated capacity. I wouldn't feel comfortable running anything less than an 850w one.

I wouldn't be surprised if you got a better hashrate with more power headroom either.

[BitSyncom]

I did some overclocking with GPUs and as far as i read the fear of people that simple overclocking can dramatically reduce the lifetime of a chip isnt correct. The biggest problem for chips is when you set the voltage higher. The electron migration (or something called similar) will make the chip go down faster this way. Thats a fast way to crash a chip.
The second way, but far less dangerous is high temperature. At least GPUs shut down when they are too hot. Asics dont do this so one should be cautious with the temperature. But a higher temperature is shortening the life of a chip but not very much.
The third is to overclock the frequency. It doesnt hurt in its own. The only danger is the high temperature. So if one manages to keep the temperature at the same level while overclocking it shouldnt hurt the chip in way that its noticeable.
If you want to make your chip live long and have better power then overclock and undervolt it. That will give higher speed, lower temperature and the overall live of the chip will be extended.

Im not a pro so if im wrong let me know.

Maybe someone can correct me if I'm wrong but I do believe the Avalon ASICS will shutdown if they get too hot. Now I doubt that each chip has a thermal sensor in it but at the very least they might have a thermal sensor somewhere on the ASIC PCBs or somewhere around. It would be pretty silly if they went through all the trouble of designing bitcoin mining ASICS and built no thermal protection in the system whatsoever. After all these are money printing machines, no?

correct, there's an hard-control on shutdown on when it overheats.

[Tyger]

so its secure, and it has its own sesnsors in it. I love it

[allinvain]

Well I took the plunge and clocked it at 300 a few minutes ago. Hashrate went up to 74G for a bit..average is 71G. Not sure for how long it will remain stable at this clock rate or if the PSU can handle it. If the Antec unit is just 650 running it at 300 mhz is probably running the PSU at 100% load. I really need to get a 850w PSU.

[PuertoLibre]

Someone else mentioned on a different thread (can't remember which one) that if you set the clock to 300 the hashrate bounces all over the place from 60 to 80 GH/s. Can anyone else confirm this wild fluctuation in hashing rate and what would be the average hashrate for an Avalon clocked at 300?

I can confirm this is the case. The Hashrate bounces all over the place, from 54GH/s to 80+.

Average is about 72~74. Consider though that the average is usually also all over the place.

[PuertoLibre]

the default is 282, and hashrate is  60G.

Does anyone tried to set it to 300?

I tried mine at 300 for about 20 minutes.  The hash rate and the shares submitted didn't change.  So I put it back to 282.  My unit was in a cold room, 0 C.

The thing is running so well that I am loath to mess with it.  I have a better spot to put it but I don't want to turn it off.

lol I'm in the same situation. I think a good investment would be to put it on a UPS. I got my eyes on a 1500VA unit - should be more than enough juice to keep it mining during brief power outages.

I looked into this last week. Though the 1500VA (by APC) are only rated for 6 minutes operation with a standalone Avalon unit.

To be honest, you'd need more juice than that just to keep it going while the power goes out. Average power outage is about 2 hours over here. 1500VA is definitely not a lot.

[allinvain]

Someone else mentioned on a different thread (can't remember which one) that if you set the clock to 300 the hashrate bounces all over the place from 60 to 80 GH/s. Can anyone else confirm this wild fluctuation in hashing rate and what would be the average hashrate for an Avalon clocked at 300?

I can confirm this is the case. The Hashrate bounces all over the place, from 54GH/s to 80+.

Average is about 72~74. Consider though that the average is usually also all over the place.

In my case it appears the hashrate does not bounce around. It's usually staying in the 68 to 74 GH/s range. My Average is 71. I'm running 03-25 firmware. Ambient temps are between 15 to 17 C.

So far I'm happy with the overclock but my main concern now is how much longer can the PSU hold under this heavy stress. But I already said many times on this thread and others that I plan to swap out that overworked antec 650 unit.

[allinvain]

the default is 282, and hashrate is  60G.

Does anyone tried to set it to 300?

I tried mine at 300 for about 20 minutes.  The hash rate and the shares submitted didn't change.  So I put it back to 282.  My unit was in a cold room, 0 C.

The thing is running so well that I am loath to mess with it.  I have a better spot to put it but I don't want to turn it off.

lol I'm in the same situation. I think a good investment would be to put it on a UPS. I got my eyes on a 1500VA unit - should be more than enough juice to keep it mining during brief power outages.

I looked into this last week. Though the 1500VA (by APC) are only rated for 6 minutes operation with a standalone Avalon unit.

To be honest, you'd need more juice than that just to keep it going while the power goes out. Average power outage is about 2 hours over here. 1500VA is definitely not a lot.

True, but higher VA units are not so easy to setup in a residential type of situation. I don't want to wire 30 amp (or heavier) circuits for a UPS. The electrical work alone will be expensive, and so will the UPS itself ($5000 to $10,000). There are other factors too that make it a challenge to engineer a adequate 100% uptime solution for these units in a RESIDENTIAL situation. A 1500VA unit is enough to ride the usual power flickers that happen. Here in my area we have reliable power and the worst that typically happens is brownouts. One solution would be to keep another miner at a family member that you trust. This way if you have an extended outtage at your home location you at least aren't losing out as much in daily earnings.

Ideally you'd want to host these in a data center, but that's a whole other discussion. Would you trust someone else with your miner?

[cypherdoc]

Someone else mentioned on a different thread (can't remember which one) that if you set the clock to 300 the hashrate bounces all over the place from 60 to 80 GH/s. Can anyone else confirm this wild fluctuation in hashing rate and what would be the average hashrate for an Avalon clocked at 300?

I can confirm this is the case. The Hashrate bounces all over the place, from 54GH/s to 80+.

Average is about 72~74. Consider though that the average is usually also all over the place.

In my case it appears the hashrate does not bounce around. It's usually staying in the 68 to 74 GH/s range. My Average is 71. I'm running 03-25 firmware. Ambient temps are between 15 to 17 C.

So far I'm happy with the overclock but my main concern now is how much longer can the PSU hold under this heavy stress. But I already said many times on this thread and others that I plan to swap out that overworked antec 650 unit.

how are u monitoring your avalons?  via ssh over the network?

[Soros Shorts]

I got an Avalon that initially appeared to be a lemon. cgminer would not start through the web interface. It could only be started from an SSH term using a start - ctrl-C - start - ctrl-C ... sequence until the units were coaxed into hashing properly. Otherwise I'd get "FPGA contoller mess up" "Avalon initialized" messages looping over and over. Once started, hashing at 282 MHz was a little unstable with the hash rate bouncing around a little.

After reading some of the comments in the other thread, I replaced the supplied Corsair GS700 PSU with a Fortress 750W Platinum I had lying around. This solved the cgminer  starting problem and the unsteady hash rate. In fact, when I switched the clock to 300 MHz it now hashes perfectly at a steady 71.5 Gh/s with the somewhat upgraded PSU.

You might want to have look at your power supply if you are having these problems.

[allinvain]

Someone else mentioned on a different thread (can't remember which one) that if you set the clock to 300 the hashrate bounces all over the place from 60 to 80 GH/s. Can anyone else confirm this wild fluctuation in hashing rate and what would be the average hashrate for an Avalon clocked at 300?

I can confirm this is the case. The Hashrate bounces all over the place, from 54GH/s to 80+.

Average is about 72~74. Consider though that the average is usually also all over the place.

In my case it appears the hashrate does not bounce around. It's usually staying in the 68 to 74 GH/s range. My Average is 71. I'm running 03-25 firmware. Ambient temps are between 15 to 17 C.

So far I'm happy with the overclock but my main concern now is how much longer can the PSU hold under this heavy stress. But I already said many times on this thread and others that I plan to swap out that overworked antec 650 unit.

how are u monitoring your avalons?  via ssh over the network?

Both. I typically just keep an eye on the cgminer status page via http, and also if I notice that cgminer has been running for a short time I hop on over to ssh and see if the actual system rebooted. Typically it's just cgminer acting up and having to be restarted.

[allinvain]

I got an Avalon that initially appeared to be a lemon. cgminer would not start through the web interface. It could only be started from an SSH term using a start - ctrl-C - start - ctrl-C ... sequence until the units were coaxed into hashing properly. Otherwise I'd get "FPGA contoller mess up" "Avalon initialized" messages looping over and over. Once started, hashing at 282 MHz was a little unstable with the hash rate bouncing around a little.

After reading some of the comments in the other thread, I replaced the supplied Corsair GS700 PSU with a Fortress 750W Platinum I had lying around. This solved the cgminer  starting problem and the unsteady hash rate. In fact, when I switched the clock to 300 MHz it now hashes perfectly at a steady 71.5 Gh/s with the somewhat upgraded PSU.

You might want to have look at your power supply if you are having these problems.

Very nice. I just finally pulled the trigger on a AX860 (80 Plus Platinum rated) so hopefully that will work out ok. Just a word of caution to those of you who are thinking of replacing the PSU, watch out and make sure the length of the PSU is not over 7 inches. A decent 800+ watt unit should be around 6 to 6.3".