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Title: usb drive vs hard drive less stales? Post by: stryker on October 30, 2011, 08:27:41 PM hmmm,
tonight I've converted my usb pen drive BAMT install to HD and already it looks like it may be a few percent lower on the stales. Dont get me wrong it was typically just under or around 1% to start with but now its 0.01 rock solid. The stales issue is all down to timing I guess, all sorts including internet connection can affect it to a degree. Just thought it was worth a mention. Question is if you have no other reason to use a hard disk will the reduction in stales pay for the hard disk being run?? :-) Title: Re: usb drive vs hard drive less stales? Post by: bulanula on October 30, 2011, 08:33:57 PM hmmm, tonight I've converted my usb pen drive BAMT install to HD and already it looks like it may be a few percent lower on the stales. Dont get me wrong it was typically just under or around 1% to start with but now its 0.01 rock solid. The stales issue is all down to timing I guess, all sorts including internet connection can affect it to a degree. Just thought it was worth a mention. Question is if you have no other reason to use a hard disk will the reduction in stales pay for the hard disk being run?? :-) Yes because the HDD produces an invisible magnetic field which reverses the polarity on the electrons in your 6990 which means they slow down which will cause them to be processed less fast so this will result in more stale shares. I think I have explained this new Bitcoinomagnetic effect. Faraday be dammed ! Title: Re: usb drive vs hard drive less stales? Post by: DeathAndTaxes on October 30, 2011, 09:03:37 PM No.
1 HDD doesn't reduce stables. 2) Even if they did, say from 0.5% to 0.01%it wouldn't pay for the increased energy usage. 0.49% increased throughput on a 1GH rig is worth about an extra $0.0004739 per hour (current difficulty and price). Break even would be <5W of power. Average hard drive uses ~10W (90% standby, 10% active) so you are still behind. 2. Short term stale rate is somewhat meaningless. Wait 7 days you may see your total stales back where they were before. My rigs average <0.1% stale rate from USB drive. If you are running linux on a dedicated mining rig (not going to be used for anything else) there is absolutely no reason to use a HDD, especially since 4GB flash drive is <$10. Title: Re: usb drive vs hard drive less stales? Post by: DeathAndTaxes on October 31, 2011, 05:33:58 PM There's another good reason, but also a caveat from my experience. The good reason is that USB mass storage is nice and easy in the logic board BIOS and you can switch off any SATA channels that may or may not support AHCI and may or may not consume power. If you like Macs but run all your dedicated miners on Linux (like me) then you don't need the additional confusion of AHCI vs IDE etc. The caveat is that if you run the Phoenix miner, and have multiple dedicated GPUs, you're likely to be running multiple instances of Phoenix, sending the output of the program to a logfile. I don't know whether this has been fixed AT LONG LAST yet... but if you leave Phoenix running for a day redirecting stdout to a logfile, you will end up with 100 MB of logs. Leave a few weeks on a flash-drive based Linux system and you may end up running out of space. The constant writing to the device also trashes the poor wear-levelling on cheap flash drives. They're not SSDs, don't treat them like such - it's actually a great idea to consider using a different filesystem (like btrfs or at least anything that doesn't run journals) if you're installing a 'normal' Linux distro install onto a flashdrive. I've broken an 8GB flashdrive stick from running Linux on it, using standard Ubuntu filesystem settings and a phoenix miner setup that wrote to logfiles and then created / deleted short versions every 3 seconds... flashdrives are NOT good for LOADS of I/O.... A +1 for cgminer then. It supports custom logging intervals. I set it to 2 minutes which is enough granularity while keeping logs small. Title: Re: usb drive vs hard drive less stales? Post by: stryker on November 01, 2011, 08:49:24 AM From way back in the early days of linux on an eeepc netbook I vaguely remember there are lots of things you can do to reduce writes to the file system when using ssd or mem stick.... seem to remember many tweaks to be done to the ext file system.
Title: Re: usb drive vs hard drive less stales? Post by: Gabi on November 01, 2011, 05:25:04 PM What about doing a ramdisk? You do not use the hard disk AND you do not use the usb drive. Less energy wasted, less wear and tear on them and you use the fastest memory on your system
Title: Re: usb drive vs hard drive less stales? Post by: DeathAndTaxes on November 01, 2011, 05:29:46 PM What about doing a ramdisk? You do not use the hard disk AND you do not use the usb drive. Less energy wasted, less wear and tear on them and you use the fastest memory on your system I thought about that. Two potential issues: 1) if system crashes or becomes unresponsive you will lose log (which is likely when you want the log) 2) most rigs use a small amoun of ram to save cost. As long as you you aren't excessively writing to usb drive (like miner updating log every second) usb are fine. My oldest rig has been running on a $5 USB drive for 7 months now. Title: Re: usb drive vs hard drive less stales? Post by: stryker on November 02, 2011, 01:27:29 PM I guess setting up a syslog server would answer that gabi.... plus as d&t says especially if you log elsewhere I don't think any RAM based usb storage solution is going to die any time soon....
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