rich1.0npub16cadfx8ew8z4qmsmsd9kndvntt4uad7vsdmkjer4jd8wjq4swxrqp2gy5dhttps://nostr.ae/npub16cadfx8ew8z4qmsmsd9kndvntt4uad7vsdmkjer4jd8wjq4swxrqp2gy5dnjumphttps://nostr.ae📅 Original date posted:2012-07-24 📝 Original message:Hi Michael, from what I have noticed, bitcoin blockchain download/verfication all happens in 1 thread. (so multicores doesnt really help) That said, I have never tried on an ssd. What I do have is 6 SATA 6gbs configed as RAID0 Drives. 32gb of ram. ubuntu 64 (yeah I know), this runs upto 16 VM's (I have 4 of these) However I have not tried to download the blockchain on the master os, just in virtulisation. However, the dedicated machines that I have been using for benchmarking the VM's against is a q6600 8gb ram sata2 hdd - Win 7 (seems faster than slackware...) to me it has always felt like network bandwidth was the issue. I might instrument the bitcoin-qt exe to only pick low ping nodes (has someone already done this?) I guess it is time to start some benchmarking (like the gpu comparison page) hte verification for the 5 past 5 days was negliglable. I am off on a flight to australia tomorrrow, so I will set some breakpoints and do some timings in a debugger. This will all happen on an e-450 (wonderful machine!) Thanks very much for your response. it would seem that I am 'doing it wrong' :/ cheers mate, steve (this message isnt signed because I have forgotten my password.) On 24/07/2012 09:25, Michael Grønager wrote: > Hi Steve, > > 45-90 minutes - note that its numbers from March/April, so a bit > longer today, but far, far away from the 12 hours. > > I am using libcoin and the bitcoind build based on this. Libcoin is > based on the Satoshi client, but refactured to use an async > concurrency model. I also did a minor tweeks to the db parameters. It > has earlier been tested up against Satoshi bitcoin where on some > OS'es it performs similarly (at least on some linuxes) and on some > faster (e.g. mac). > > What is your CPU load during a block download ? (both initially/up to > the point where verification sets in and after). The initial download > is typically disk I/O bound, the verification stage CPU bound, though > I lean to believe that even there it is disk I/O bound (at least on > my system ~50% CPU load). What should be better in libcoin is the > concurrency model. The Satoshi client uses a pure reentrant mutexes > model, that is not generally believed to motivate the best coding > practice nor performance, you might end up without the concurrency > you initially strived for *). As mentioned earlier libcoin uses a > pure async concurrency model (and so does libbitcoin btw). > > I would like to stress again that these numbers will depend largely > on the system running the test - I would call my laptop a bit over > the average today (MB Pro, 2.66Ghz i7 dual core, 8GBRAM, 512GB SSD). > But again 12 hours - I only reach such numbers on some of my VPS'es > (linode 1024) that are known for notoriously slow disk I/O. (here I > have a few % CPU load during the verification indicating indeed that > the disk i/o is the culprit). > > Cheers, > > Michael > > > *) I like this Dave Butenhof quote: "The biggest of all the big > problems with recursive mutexes is that they encourage you to > completely lose track of your locking scheme and scope. This is > deadly. Evil. It's the "thread eater". You hold locks for the > absolutely shortest possible time. Period. Always. If you're calling > something with a lock held simply because you don't know it's held, > or because you don't know whether the callee needs the mutex, then > you're holding it too long. You're aiming a shotgun at your > application and pulling the trigger. You presumably started using > threads to get concurrency; but you've just PREVENTED concurrency." > > > > > On 23/07/2012, at 17:54, steve wrote: > > Hi Michael, > > On 23/07/2012 10:00, Michael Grønager wrote: >>>> I get a full blockchain from scratch in 45 minutes on my >>>> laptop, /M >>>> > Hang on a sec, in 45 minutes you can download the entire chain from > the genesis block? > > I have been doing extensive testing in this area and would love to > know what is special about your setup (I have never had the entire > chain in under 12 hours, infact it is normally closerto 24.) I have > an extensive setup of test machines, everything from e4300 to > phenom2x6 to i5's. > > as an example on an amd e-450 with 4gb ram, and approx 3gb/s > internet connection it took 2 hours to sync the last 5 days. > > Maybe i am missing something important... > > Any additional information that you could provide to help me with > testing would be really appreciated. > > cheers, > > steve > >> >> ------------------------------------------------------------------------------ >> >> Live Security Virtual Conference >> Exclusive live event will cover all the ways today's security and >> threat landscape has changed and how IT managers can respond. >> Discussions will include endpoint security, mobile security and the >> latest in malware threats. >> http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ >> _______________________________________________ Bitcoin-development >> mailing list Bitcoin-development at lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/bitcoin-development > > > > >